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/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.commons.text;

import java.io.IOException;
import java.io.Reader;
import java.io.Serializable;
import java.io.Writer;
import java.nio.CharBuffer;
import java.util.Iterator;
import java.util.List;
import java.util.Objects;

/**
 * Builds a string from constituent parts providing a more flexible and powerful API
 * than StringBuffer.
 * 

* The main differences from StringBuffer/StringBuilder are: *

*
    *
  • Not synchronized
  • *
  • Not final
  • *
  • Subclasses have direct access to character array
  • *
  • Additional methods *
      *
    • appendWithSeparators - adds an array of values, with a separator
    • *
    • appendPadding - adds a length padding characters
    • *
    • appendFixedLength - adds a fixed width field to the builder
    • *
    • toCharArray/getChars - simpler ways to get a range of the character array
    • *
    • delete - delete char or string
    • *
    • replace - search and replace for a char or string
    • *
    • leftString/rightString/midString - substring without exceptions
    • *
    • contains - whether the builder contains a char or string
    • *
    • size/clear/isEmpty - collections style API methods
    • *
    *
  • *
  • Views *
      *
    • asTokenizer - uses the internal buffer as the source of a StrTokenizer
    • *
    • asReader - uses the internal buffer as the source of a Reader
    • *
    • asWriter - allows a Writer to write directly to the internal buffer
    • *
    *
  • *
*

* The aim has been to provide an API that mimics very closely what StringBuffer * provides, but with additional methods. It should be noted that some edge cases, * with invalid indices or null input, have been altered - see individual methods. * The biggest of these changes is that by default, null will not output the text * 'null'. This can be controlled by a property, {@link #setNullText(String)}. *

* * @since 1.0 * */ public class StrBuilder implements CharSequence, Appendable, Serializable, Builder { /** * The extra capacity for new builders. */ static final int CAPACITY = 32; /** * Required for serialization support. * * @see java.io.Serializable */ private static final long serialVersionUID = 7628716375283629643L; /** Internal data storage. */ char[] buffer; // package-protected for test code use only /** Current size of the buffer. */ private int size; /** The new line. */ private String newLine; /** The null text. */ private String nullText; //----------------------------------------------------------------------- /** * Constructor that creates an empty builder initial capacity 32 characters. */ public StrBuilder() { this(CAPACITY); } /** * Constructor that creates an empty builder the specified initial capacity. * * @param initialCapacity the initial capacity, zero or less will be converted to 32 */ public StrBuilder(int initialCapacity) { super(); if (initialCapacity <= 0) { initialCapacity = CAPACITY; } buffer = new char[initialCapacity]; } /** * Constructor that creates a builder from the string, allocating * 32 extra characters for growth. * * @param str the string to copy, null treated as blank string */ public StrBuilder(final String str) { super(); if (str == null) { buffer = new char[CAPACITY]; } else { buffer = new char[str.length() + CAPACITY]; append(str); } } //----------------------------------------------------------------------- /** * Gets the text to be appended when a new line is added. * * @return the new line text, null means use system default */ public String getNewLineText() { return newLine; } /** * Sets the text to be appended when a new line is added. * * @param newLine the new line text, null means use system default * @return this, to enable chaining */ public StrBuilder setNewLineText(final String newLine) { this.newLine = newLine; return this; } //----------------------------------------------------------------------- /** * Gets the text to be appended when null is added. * * @return the null text, null means no append */ public String getNullText() { return nullText; } /** * Sets the text to be appended when null is added. * * @param nullText the null text, null means no append * @return this, to enable chaining */ public StrBuilder setNullText(String nullText) { if (nullText != null && nullText.isEmpty()) { nullText = null; } this.nullText = nullText; return this; } //----------------------------------------------------------------------- /** * Gets the length of the string builder. * * @return the length */ @Override public int length() { return size; } /** * Updates the length of the builder by either dropping the last characters * or adding filler of Unicode zero. * * @param length the length to set to, must be zero or positive * @return this, to enable chaining * @throws IndexOutOfBoundsException if the length is negative */ public StrBuilder setLength(final int length) { if (length < 0) { throw new StringIndexOutOfBoundsException(length); } if (length < size) { size = length; } else if (length > size) { ensureCapacity(length); final int oldEnd = size; final int newEnd = length; size = length; for (int i = oldEnd; i < newEnd; i++) { buffer[i] = '\0'; } } return this; } //----------------------------------------------------------------------- /** * Gets the current size of the internal character array buffer. * * @return the capacity */ public int capacity() { return buffer.length; } /** * Checks the capacity and ensures that it is at least the size specified. * * @param capacity the capacity to ensure * @return this, to enable chaining */ public StrBuilder ensureCapacity(final int capacity) { if (capacity > buffer.length) { final char[] old = buffer; buffer = new char[capacity * 2]; System.arraycopy(old, 0, buffer, 0, size); } return this; } /** * Minimizes the capacity to the actual length of the string. * * @return this, to enable chaining */ public StrBuilder minimizeCapacity() { if (buffer.length > length()) { final char[] old = buffer; buffer = new char[length()]; System.arraycopy(old, 0, buffer, 0, size); } return this; } //----------------------------------------------------------------------- /** * Gets the length of the string builder. *

* This method is the same as {@link #length()} and is provided to match the * API of Collections. * * @return the length */ public int size() { return size; } /** * Checks is the string builder is empty (convenience Collections API style method). *

* This method is the same as checking {@link #length()} and is provided to match the * API of Collections. * * @return true if the size is 0. */ public boolean isEmpty() { return size == 0; } /** * Clears the string builder (convenience Collections API style method). *

* This method does not reduce the size of the internal character buffer. * To do that, call clear() followed by {@link #minimizeCapacity()}. *

* This method is the same as {@link #setLength(int)} called with zero * and is provided to match the API of Collections. * * @return this, to enable chaining */ public StrBuilder clear() { size = 0; return this; } //----------------------------------------------------------------------- /** * Gets the character at the specified index. * * @see #setCharAt(int, char) * @see #deleteCharAt(int) * @param index the index to retrieve, must be valid * @return the character at the index * @throws IndexOutOfBoundsException if the index is invalid */ @Override public char charAt(final int index) { if (index < 0 || index >= length()) { throw new StringIndexOutOfBoundsException(index); } return buffer[index]; } /** * Sets the character at the specified index. * * @see #charAt(int) * @see #deleteCharAt(int) * @param index the index to set * @param ch the new character * @return this, to enable chaining * @throws IndexOutOfBoundsException if the index is invalid */ public StrBuilder setCharAt(final int index, final char ch) { if (index < 0 || index >= length()) { throw new StringIndexOutOfBoundsException(index); } buffer[index] = ch; return this; } /** * Deletes the character at the specified index. * * @see #charAt(int) * @see #setCharAt(int, char) * @param index the index to delete * @return this, to enable chaining * @throws IndexOutOfBoundsException if the index is invalid */ public StrBuilder deleteCharAt(final int index) { if (index < 0 || index >= size) { throw new StringIndexOutOfBoundsException(index); } deleteImpl(index, index + 1, 1); return this; } //----------------------------------------------------------------------- /** * Copies the builder's character array into a new character array. * * @return a new array that represents the contents of the builder */ public char[] toCharArray() { if (size == 0) { return new char[0]; } final char[] chars = new char[size]; System.arraycopy(buffer, 0, chars, 0, size); return chars; } /** * Copies part of the builder's character array into a new character array. * * @param startIndex the start index, inclusive, must be valid * @param endIndex the end index, exclusive, must be valid except that * if too large it is treated as end of string * @return a new array that holds part of the contents of the builder * @throws IndexOutOfBoundsException if startIndex is invalid, * or if endIndex is invalid (but endIndex greater than size is valid) */ public char[] toCharArray(final int startIndex, int endIndex) { endIndex = validateRange(startIndex, endIndex); final int len = endIndex - startIndex; if (len == 0) { return new char[0]; } final char[] chars = new char[len]; System.arraycopy(buffer, startIndex, chars, 0, len); return chars; } /** * Copies the character array into the specified array. * * @param destination the destination array, null will cause an array to be created * @return the input array, unless that was null or too small */ public char[] getChars(char[] destination) { final int len = length(); if (destination == null || destination.length < len) { destination = new char[len]; } System.arraycopy(buffer, 0, destination, 0, len); return destination; } /** * Copies the character array into the specified array. * * @param startIndex first index to copy, inclusive, must be valid * @param endIndex last index, exclusive, must be valid * @param destination the destination array, must not be null or too small * @param destinationIndex the index to start copying in destination * @throws NullPointerException if the array is null * @throws IndexOutOfBoundsException if any index is invalid */ public void getChars(final int startIndex, final int endIndex, final char[] destination, final int destinationIndex) { if (startIndex < 0) { throw new StringIndexOutOfBoundsException(startIndex); } if (endIndex < 0 || endIndex > length()) { throw new StringIndexOutOfBoundsException(endIndex); } if (startIndex > endIndex) { throw new StringIndexOutOfBoundsException("end < start"); } System.arraycopy(buffer, startIndex, destination, destinationIndex, endIndex - startIndex); } //----------------------------------------------------------------------- /** * If possible, reads chars from the provided {@link Readable} directly into underlying * character buffer without making extra copies. * * @param readable object to read from * @return the number of characters read * @throws IOException if an I/O error occurs * * @see #appendTo(Appendable) */ public int readFrom(final Readable readable) throws IOException { final int oldSize = size; if (readable instanceof Reader) { final Reader r = (Reader) readable; ensureCapacity(size + 1); int read; while ((read = r.read(buffer, size, buffer.length - size)) != -1) { size += read; ensureCapacity(size + 1); } } else if (readable instanceof CharBuffer) { final CharBuffer cb = (CharBuffer) readable; final int remaining = cb.remaining(); ensureCapacity(size + remaining); cb.get(buffer, size, remaining); size += remaining; } else { while (true) { ensureCapacity(size + 1); final CharBuffer buf = CharBuffer.wrap(buffer, size, buffer.length - size); final int read = readable.read(buf); if (read == -1) { break; } size += read; } } return size - oldSize; } //----------------------------------------------------------------------- /** * Appends the new line string to this string builder. *

* The new line string can be altered using {@link #setNewLineText(String)}. * This might be used to force the output to always use Unix line endings * even when on Windows. * * @return this, to enable chaining */ public StrBuilder appendNewLine() { if (newLine == null) { append(System.getProperty("line.separator")); return this; } return append(newLine); } /** * Appends the text representing null to this string builder. * * @return this, to enable chaining */ public StrBuilder appendNull() { if (nullText == null) { return this; } return append(nullText); } /** * Appends an object to this string builder. * Appending null will call {@link #appendNull()}. * * @param obj the object to append * @return this, to enable chaining */ public StrBuilder append(final Object obj) { if (obj == null) { return appendNull(); } if (obj instanceof CharSequence) { return append((CharSequence) obj); } return append(obj.toString()); } /** * Appends a CharSequence to this string builder. * Appending null will call {@link #appendNull()}. * * @param seq the CharSequence to append * @return this, to enable chaining */ @Override public StrBuilder append(final CharSequence seq) { if (seq == null) { return appendNull(); } if (seq instanceof StrBuilder) { return append((StrBuilder) seq); } if (seq instanceof StringBuilder) { return append((StringBuilder) seq); } if (seq instanceof StringBuffer) { return append((StringBuffer) seq); } if (seq instanceof CharBuffer) { return append((CharBuffer) seq); } return append(seq.toString()); } /** * Appends part of a CharSequence to this string builder. * Appending null will call {@link #appendNull()}. * * @param seq the CharSequence to append * @param startIndex the start index, inclusive, must be valid * @param length the length to append, must be valid * @return this, to enable chaining */ @Override public StrBuilder append(final CharSequence seq, final int startIndex, final int length) { if (seq == null) { return appendNull(); } return append(seq.toString(), startIndex, length); } /** * Appends a string to this string builder. * Appending null will call {@link #appendNull()}. * * @param str the string to append * @return this, to enable chaining */ public StrBuilder append(final String str) { if (str == null) { return appendNull(); } final int strLen = str.length(); if (strLen > 0) { final int len = length(); ensureCapacity(len + strLen); str.getChars(0, strLen, buffer, len); size += strLen; } return this; } /** * Appends part of a string to this string builder. * Appending null will call {@link #appendNull()}. * * @param str the string to append * @param startIndex the start index, inclusive, must be valid * @param length the length to append, must be valid * @return this, to enable chaining */ public StrBuilder append(final String str, final int startIndex, final int length) { if (str == null) { return appendNull(); } if (startIndex < 0 || startIndex > str.length()) { throw new StringIndexOutOfBoundsException("startIndex must be valid"); } if (length < 0 || (startIndex + length) > str.length()) { throw new StringIndexOutOfBoundsException("length must be valid"); } if (length > 0) { final int len = length(); ensureCapacity(len + length); str.getChars(startIndex, startIndex + length, buffer, len); size += length; } return this; } /** * Calls {@link String#format(String, Object...)} and appends the result. * * @param format the format string * @param objs the objects to use in the format string * @return {@code this} to enable chaining * @see String#format(String, Object...) */ public StrBuilder append(final String format, final Object... objs) { return append(String.format(format, objs)); } /** * Appends the contents of a char buffer to this string builder. * Appending null will call {@link #appendNull()}. * * @param buf the char buffer to append * @return this, to enable chaining */ public StrBuilder append(final CharBuffer buf) { if (buf == null) { return appendNull(); } if (buf.hasArray()) { final int length = buf.remaining(); final int len = length(); ensureCapacity(len + length); System.arraycopy(buf.array(), buf.arrayOffset() + buf.position(), buffer, len, length); size += length; } else { append(buf.toString()); } return this; } /** * Appends the contents of a char buffer to this string builder. * Appending null will call {@link #appendNull()}. * * @param buf the char buffer to append * @param startIndex the start index, inclusive, must be valid * @param length the length to append, must be valid * @return this, to enable chaining */ public StrBuilder append(final CharBuffer buf, final int startIndex, final int length) { if (buf == null) { return appendNull(); } if (buf.hasArray()) { final int totalLength = buf.remaining(); if (startIndex < 0 || startIndex > totalLength) { throw new StringIndexOutOfBoundsException("startIndex must be valid"); } if (length < 0 || (startIndex + length) > totalLength) { throw new StringIndexOutOfBoundsException("length must be valid"); } final int len = length(); ensureCapacity(len + length); System.arraycopy(buf.array(), buf.arrayOffset() + buf.position() + startIndex, buffer, len, length); size += length; } else { append(buf.toString(), startIndex, length); } return this; } /** * Appends a string buffer to this string builder. * Appending null will call {@link #appendNull()}. * * @param str the string buffer to append * @return this, to enable chaining */ public StrBuilder append(final StringBuffer str) { if (str == null) { return appendNull(); } final int strLen = str.length(); if (strLen > 0) { final int len = length(); ensureCapacity(len + strLen); str.getChars(0, strLen, buffer, len); size += strLen; } return this; } /** * Appends part of a string buffer to this string builder. * Appending null will call {@link #appendNull()}. * * @param str the string to append * @param startIndex the start index, inclusive, must be valid * @param length the length to append, must be valid * @return this, to enable chaining */ public StrBuilder append(final StringBuffer str, final int startIndex, final int length) { if (str == null) { return appendNull(); } if (startIndex < 0 || startIndex > str.length()) { throw new StringIndexOutOfBoundsException("startIndex must be valid"); } if (length < 0 || (startIndex + length) > str.length()) { throw new StringIndexOutOfBoundsException("length must be valid"); } if (length > 0) { final int len = length(); ensureCapacity(len + length); str.getChars(startIndex, startIndex + length, buffer, len); size += length; } return this; } /** * Appends a StringBuilder to this string builder. * Appending null will call {@link #appendNull()}. * * @param str the StringBuilder to append * @return this, to enable chaining */ public StrBuilder append(final StringBuilder str) { if (str == null) { return appendNull(); } final int strLen = str.length(); if (strLen > 0) { final int len = length(); ensureCapacity(len + strLen); str.getChars(0, strLen, buffer, len); size += strLen; } return this; } /** * Appends part of a StringBuilder to this string builder. * Appending null will call {@link #appendNull()}. * * @param str the StringBuilder to append * @param startIndex the start index, inclusive, must be valid * @param length the length to append, must be valid * @return this, to enable chaining */ public StrBuilder append(final StringBuilder str, final int startIndex, final int length) { if (str == null) { return appendNull(); } if (startIndex < 0 || startIndex > str.length()) { throw new StringIndexOutOfBoundsException("startIndex must be valid"); } if (length < 0 || (startIndex + length) > str.length()) { throw new StringIndexOutOfBoundsException("length must be valid"); } if (length > 0) { final int len = length(); ensureCapacity(len + length); str.getChars(startIndex, startIndex + length, buffer, len); size += length; } return this; } /** * Appends another string builder to this string builder. * Appending null will call {@link #appendNull()}. * * @param str the string builder to append * @return this, to enable chaining */ public StrBuilder append(final StrBuilder str) { if (str == null) { return appendNull(); } final int strLen = str.length(); if (strLen > 0) { final int len = length(); ensureCapacity(len + strLen); System.arraycopy(str.buffer, 0, buffer, len, strLen); size += strLen; } return this; } /** * Appends part of a string builder to this string builder. * Appending null will call {@link #appendNull()}. * * @param str the string to append * @param startIndex the start index, inclusive, must be valid * @param length the length to append, must be valid * @return this, to enable chaining */ public StrBuilder append(final StrBuilder str, final int startIndex, final int length) { if (str == null) { return appendNull(); } if (startIndex < 0 || startIndex > str.length()) { throw new StringIndexOutOfBoundsException("startIndex must be valid"); } if (length < 0 || (startIndex + length) > str.length()) { throw new StringIndexOutOfBoundsException("length must be valid"); } if (length > 0) { final int len = length(); ensureCapacity(len + length); str.getChars(startIndex, startIndex + length, buffer, len); size += length; } return this; } /** * Appends a char array to the string builder. * Appending null will call {@link #appendNull()}. * * @param chars the char array to append * @return this, to enable chaining */ public StrBuilder append(final char[] chars) { if (chars == null) { return appendNull(); } final int strLen = chars.length; if (strLen > 0) { final int len = length(); ensureCapacity(len + strLen); System.arraycopy(chars, 0, buffer, len, strLen); size += strLen; } return this; } /** * Appends a char array to the string builder. * Appending null will call {@link #appendNull()}. * * @param chars the char array to append * @param startIndex the start index, inclusive, must be valid * @param length the length to append, must be valid * @return this, to enable chaining */ public StrBuilder append(final char[] chars, final int startIndex, final int length) { if (chars == null) { return appendNull(); } if (startIndex < 0 || startIndex > chars.length) { throw new StringIndexOutOfBoundsException("Invalid startIndex: " + length); } if (length < 0 || (startIndex + length) > chars.length) { throw new StringIndexOutOfBoundsException("Invalid length: " + length); } if (length > 0) { final int len = length(); ensureCapacity(len + length); System.arraycopy(chars, startIndex, buffer, len, length); size += length; } return this; } /** * Appends a boolean value to the string builder. * * @param value the value to append * @return this, to enable chaining */ public StrBuilder append(final boolean value) { if (value) { ensureCapacity(size + 4); buffer[size++] = 't'; buffer[size++] = 'r'; buffer[size++] = 'u'; buffer[size++] = 'e'; } else { ensureCapacity(size + 5); buffer[size++] = 'f'; buffer[size++] = 'a'; buffer[size++] = 'l'; buffer[size++] = 's'; buffer[size++] = 'e'; } return this; } /** * Appends a char value to the string builder. * * @param ch the value to append * @return this, to enable chaining */ @Override public StrBuilder append(final char ch) { final int len = length(); ensureCapacity(len + 1); buffer[size++] = ch; return this; } /** * Appends an int value to the string builder using String.valueOf. * * @param value the value to append * @return this, to enable chaining */ public StrBuilder append(final int value) { return append(String.valueOf(value)); } /** * Appends a long value to the string builder using String.valueOf. * * @param value the value to append * @return this, to enable chaining */ public StrBuilder append(final long value) { return append(String.valueOf(value)); } /** * Appends a float value to the string builder using String.valueOf. * * @param value the value to append * @return this, to enable chaining */ public StrBuilder append(final float value) { return append(String.valueOf(value)); } /** * Appends a double value to the string builder using String.valueOf. * * @param value the value to append * @return this, to enable chaining */ public StrBuilder append(final double value) { return append(String.valueOf(value)); } //----------------------------------------------------------------------- /** * Appends an object followed by a new line to this string builder. * Appending null will call {@link #appendNull()}. * * @param obj the object to append * @return this, to enable chaining */ public StrBuilder appendln(final Object obj) { return append(obj).appendNewLine(); } /** * Appends a string followed by a new line to this string builder. * Appending null will call {@link #appendNull()}. * * @param str the string to append * @return this, to enable chaining */ public StrBuilder appendln(final String str) { return append(str).appendNewLine(); } /** * Appends part of a string followed by a new line to this string builder. * Appending null will call {@link #appendNull()}. * * @param str the string to append * @param startIndex the start index, inclusive, must be valid * @param length the length to append, must be valid * @return this, to enable chaining */ public StrBuilder appendln(final String str, final int startIndex, final int length) { return append(str, startIndex, length).appendNewLine(); } /** * Calls {@link String#format(String, Object...)} and appends the result. * * @param format the format string * @param objs the objects to use in the format string * @return {@code this} to enable chaining * @see String#format(String, Object...) */ public StrBuilder appendln(final String format, final Object... objs) { return append(format, objs).appendNewLine(); } /** * Appends a string buffer followed by a new line to this string builder. * Appending null will call {@link #appendNull()}. * * @param str the string buffer to append * @return this, to enable chaining */ public StrBuilder appendln(final StringBuffer str) { return append(str).appendNewLine(); } /** * Appends a string builder followed by a new line to this string builder. * Appending null will call {@link #appendNull()}. * * @param str the string builder to append * @return this, to enable chaining */ public StrBuilder appendln(final StringBuilder str) { return append(str).appendNewLine(); } /** * Appends part of a string builder followed by a new line to this string builder. * Appending null will call {@link #appendNull()}. * * @param str the string builder to append * @param startIndex the start index, inclusive, must be valid * @param length the length to append, must be valid * @return this, to enable chaining */ public StrBuilder appendln(final StringBuilder str, final int startIndex, final int length) { return append(str, startIndex, length).appendNewLine(); } /** * Appends part of a string buffer followed by a new line to this string builder. * Appending null will call {@link #appendNull()}. * * @param str the string to append * @param startIndex the start index, inclusive, must be valid * @param length the length to append, must be valid * @return this, to enable chaining */ public StrBuilder appendln(final StringBuffer str, final int startIndex, final int length) { return append(str, startIndex, length).appendNewLine(); } /** * Appends another string builder followed by a new line to this string builder. * Appending null will call {@link #appendNull()}. * * @param str the string builder to append * @return this, to enable chaining */ public StrBuilder appendln(final StrBuilder str) { return append(str).appendNewLine(); } /** * Appends part of a string builder followed by a new line to this string builder. * Appending null will call {@link #appendNull()}. * * @param str the string to append * @param startIndex the start index, inclusive, must be valid * @param length the length to append, must be valid * @return this, to enable chaining */ public StrBuilder appendln(final StrBuilder str, final int startIndex, final int length) { return append(str, startIndex, length).appendNewLine(); } /** * Appends a char array followed by a new line to the string builder. * Appending null will call {@link #appendNull()}. * * @param chars the char array to append * @return this, to enable chaining */ public StrBuilder appendln(final char[] chars) { return append(chars).appendNewLine(); } /** * Appends a char array followed by a new line to the string builder. * Appending null will call {@link #appendNull()}. * * @param chars the char array to append * @param startIndex the start index, inclusive, must be valid * @param length the length to append, must be valid * @return this, to enable chaining */ public StrBuilder appendln(final char[] chars, final int startIndex, final int length) { return append(chars, startIndex, length).appendNewLine(); } /** * Appends a boolean value followed by a new line to the string builder. * * @param value the value to append * @return this, to enable chaining */ public StrBuilder appendln(final boolean value) { return append(value).appendNewLine(); } /** * Appends a char value followed by a new line to the string builder. * * @param ch the value to append * @return this, to enable chaining */ public StrBuilder appendln(final char ch) { return append(ch).appendNewLine(); } /** * Appends an int value followed by a new line to the string builder using String.valueOf. * * @param value the value to append * @return this, to enable chaining */ public StrBuilder appendln(final int value) { return append(value).appendNewLine(); } /** * Appends a long value followed by a new line to the string builder using String.valueOf. * * @param value the value to append * @return this, to enable chaining */ public StrBuilder appendln(final long value) { return append(value).appendNewLine(); } /** * Appends a float value followed by a new line to the string builder using String.valueOf. * * @param value the value to append * @return this, to enable chaining */ public StrBuilder appendln(final float value) { return append(value).appendNewLine(); } /** * Appends a double value followed by a new line to the string builder using String.valueOf. * * @param value the value to append * @return this, to enable chaining */ public StrBuilder appendln(final double value) { return append(value).appendNewLine(); } //----------------------------------------------------------------------- /** * Appends each item in an array to the builder without any separators. * Appending a null array will have no effect. * Each object is appended using {@link #append(Object)}. * * @param the element type * @param array the array to append * @return this, to enable chaining */ public StrBuilder appendAll(@SuppressWarnings("unchecked") final T... array) { /* * @SuppressWarnings used to hide warning about vararg usage. We cannot * use @SafeVarargs, since this method is not final. Using @SupressWarnings * is fine, because it isn't inherited by subclasses, so each subclass must * vouch for itself whether its use of 'array' is safe. */ if (array != null && array.length > 0) { for (final Object element : array) { append(element); } } return this; } /** * Appends each item in an iterable to the builder without any separators. * Appending a null iterable will have no effect. * Each object is appended using {@link #append(Object)}. * * @param iterable the iterable to append * @return this, to enable chaining */ public StrBuilder appendAll(final Iterable iterable) { if (iterable != null) { for (final Object o : iterable) { append(o); } } return this; } /** * Appends each item in an iterator to the builder without any separators. * Appending a null iterator will have no effect. * Each object is appended using {@link #append(Object)}. * * @param it the iterator to append * @return this, to enable chaining */ public StrBuilder appendAll(final Iterator it) { if (it != null) { while (it.hasNext()) { append(it.next()); } } return this; } //----------------------------------------------------------------------- /** * Appends an array placing separators between each value, but * not before the first or after the last. * Appending a null array will have no effect. * Each object is appended using {@link #append(Object)}. * * @param array the array to append * @param separator the separator to use, null means no separator * @return this, to enable chaining */ public StrBuilder appendWithSeparators(final Object[] array, final String separator) { if (array != null && array.length > 0) { final String sep = Objects.toString(separator, ""); append(array[0]); for (int i = 1; i < array.length; i++) { append(sep); append(array[i]); } } return this; } /** * Appends an iterable placing separators between each value, but * not before the first or after the last. * Appending a null iterable will have no effect. * Each object is appended using {@link #append(Object)}. * * @param iterable the iterable to append * @param separator the separator to use, null means no separator * @return this, to enable chaining */ public StrBuilder appendWithSeparators(final Iterable iterable, final String separator) { if (iterable != null) { final String sep = Objects.toString(separator, ""); final Iterator it = iterable.iterator(); while (it.hasNext()) { append(it.next()); if (it.hasNext()) { append(sep); } } } return this; } /** * Appends an iterator placing separators between each value, but * not before the first or after the last. * Appending a null iterator will have no effect. * Each object is appended using {@link #append(Object)}. * * @param it the iterator to append * @param separator the separator to use, null means no separator * @return this, to enable chaining */ public StrBuilder appendWithSeparators(final Iterator it, final String separator) { if (it != null) { final String sep = Objects.toString(separator, ""); while (it.hasNext()) { append(it.next()); if (it.hasNext()) { append(sep); } } } return this; } //----------------------------------------------------------------------- /** * Appends a separator if the builder is currently non-empty. * Appending a null separator will have no effect. * The separator is appended using {@link #append(String)}. *

* This method is useful for adding a separator each time around the * loop except the first. *

     * for (Iterator it = list.iterator(); it.hasNext(); ) {
     *   appendSeparator(",");
     *   append(it.next());
     * }
     * 
* Note that for this simple example, you should use * {@link #appendWithSeparators(Iterable, String)}. * * @param separator the separator to use, null means no separator * @return this, to enable chaining */ public StrBuilder appendSeparator(final String separator) { return appendSeparator(separator, null); } /** * Appends one of both separators to the StrBuilder. * If the builder is currently empty it will append the defaultIfEmpty-separator * Otherwise it will append the standard-separator * * Appending a null separator will have no effect. * The separator is appended using {@link #append(String)}. *

* This method is for example useful for constructing queries *

     * StrBuilder whereClause = new StrBuilder();
     * if(searchCommand.getPriority() != null) {
     *  whereClause.appendSeparator(" and", " where");
     *  whereClause.append(" priority = ?")
     * }
     * if(searchCommand.getComponent() != null) {
     *  whereClause.appendSeparator(" and", " where");
     *  whereClause.append(" component = ?")
     * }
     * selectClause.append(whereClause)
     * 
* * @param standard the separator if builder is not empty, null means no separator * @param defaultIfEmpty the separator if builder is empty, null means no separator * @return this, to enable chaining */ public StrBuilder appendSeparator(final String standard, final String defaultIfEmpty) { final String str = isEmpty() ? defaultIfEmpty : standard; if (str != null) { append(str); } return this; } /** * Appends a separator if the builder is currently non-empty. * The separator is appended using {@link #append(char)}. *

* This method is useful for adding a separator each time around the * loop except the first. *

     * for (Iterator it = list.iterator(); it.hasNext(); ) {
     *   appendSeparator(',');
     *   append(it.next());
     * }
     * 
* Note that for this simple example, you should use * {@link #appendWithSeparators(Iterable, String)}. * * @param separator the separator to use * @return this, to enable chaining */ public StrBuilder appendSeparator(final char separator) { if (size() > 0) { append(separator); } return this; } /** * Append one of both separators to the builder * If the builder is currently empty it will append the defaultIfEmpty-separator * Otherwise it will append the standard-separator * * The separator is appended using {@link #append(char)}. * @param standard the separator if builder is not empty * @param defaultIfEmpty the separator if builder is empty * @return this, to enable chaining */ public StrBuilder appendSeparator(final char standard, final char defaultIfEmpty) { if (size() > 0) { append(standard); } else { append(defaultIfEmpty); } return this; } /** * Appends a separator to the builder if the loop index is greater than zero. * Appending a null separator will have no effect. * The separator is appended using {@link #append(String)}. *

* This method is useful for adding a separator each time around the * loop except the first. *

*
     * for (int i = 0; i < list.size(); i++) {
     *   appendSeparator(",", i);
     *   append(list.get(i));
     * }
     * 
* Note that for this simple example, you should use * {@link #appendWithSeparators(Iterable, String)}. * * @param separator the separator to use, null means no separator * @param loopIndex the loop index * @return this, to enable chaining */ public StrBuilder appendSeparator(final String separator, final int loopIndex) { if (separator != null && loopIndex > 0) { append(separator); } return this; } /** * Appends a separator to the builder if the loop index is greater than zero. * The separator is appended using {@link #append(char)}. *

* This method is useful for adding a separator each time around the * loop except the first. *

*
     * for (int i = 0; i < list.size(); i++) {
     *   appendSeparator(",", i);
     *   append(list.get(i));
     * }
     * 
* Note that for this simple example, you should use * {@link #appendWithSeparators(Iterable, String)}. * * @param separator the separator to use * @param loopIndex the loop index * @return this, to enable chaining */ public StrBuilder appendSeparator(final char separator, final int loopIndex) { if (loopIndex > 0) { append(separator); } return this; } //----------------------------------------------------------------------- /** * Appends the pad character to the builder the specified number of times. * * @param length the length to append, negative means no append * @param padChar the character to append * @return this, to enable chaining */ public StrBuilder appendPadding(final int length, final char padChar) { if (length >= 0) { ensureCapacity(size + length); for (int i = 0; i < length; i++) { buffer[size++] = padChar; } } return this; } //----------------------------------------------------------------------- /** * Appends an object to the builder padding on the left to a fixed width. * The toString of the object is used. * If the object is larger than the length, the left hand side is lost. * If the object is null, the null text value is used. * * @param obj the object to append, null uses null text * @param width the fixed field width, zero or negative has no effect * @param padChar the pad character to use * @return this, to enable chaining */ public StrBuilder appendFixedWidthPadLeft(final Object obj, final int width, final char padChar) { if (width > 0) { ensureCapacity(size + width); String str = (obj == null ? getNullText() : obj.toString()); if (str == null) { str = ""; } final int strLen = str.length(); if (strLen >= width) { str.getChars(strLen - width, strLen, buffer, size); } else { final int padLen = width - strLen; for (int i = 0; i < padLen; i++) { buffer[size + i] = padChar; } str.getChars(0, strLen, buffer, size + padLen); } size += width; } return this; } /** * Appends an object to the builder padding on the left to a fixed width. * The String.valueOf of the int value is used. * If the formatted value is larger than the length, the left hand side is lost. * * @param value the value to append * @param width the fixed field width, zero or negative has no effect * @param padChar the pad character to use * @return this, to enable chaining */ public StrBuilder appendFixedWidthPadLeft(final int value, final int width, final char padChar) { return appendFixedWidthPadLeft(String.valueOf(value), width, padChar); } /** * Appends an object to the builder padding on the right to a fixed length. * The toString of the object is used. * If the object is larger than the length, the right hand side is lost. * If the object is null, null text value is used. * * @param obj the object to append, null uses null text * @param width the fixed field width, zero or negative has no effect * @param padChar the pad character to use * @return this, to enable chaining */ public StrBuilder appendFixedWidthPadRight(final Object obj, final int width, final char padChar) { if (width > 0) { ensureCapacity(size + width); String str = (obj == null ? getNullText() : obj.toString()); if (str == null) { str = ""; } final int strLen = str.length(); if (strLen >= width) { str.getChars(0, width, buffer, size); } else { final int padLen = width - strLen; str.getChars(0, strLen, buffer, size); for (int i = 0; i < padLen; i++) { buffer[size + strLen + i] = padChar; } } size += width; } return this; } /** * Appends an object to the builder padding on the right to a fixed length. * The String.valueOf of the int value is used. * If the object is larger than the length, the right hand side is lost. * * @param value the value to append * @param width the fixed field width, zero or negative has no effect * @param padChar the pad character to use * @return this, to enable chaining */ public StrBuilder appendFixedWidthPadRight(final int value, final int width, final char padChar) { return appendFixedWidthPadRight(String.valueOf(value), width, padChar); } //----------------------------------------------------------------------- /** * Inserts the string representation of an object into this builder. * Inserting null will use the stored null text value. * * @param index the index to add at, must be valid * @param obj the object to insert * @return this, to enable chaining * @throws IndexOutOfBoundsException if the index is invalid */ public StrBuilder insert(final int index, final Object obj) { if (obj == null) { return insert(index, nullText); } return insert(index, obj.toString()); } /** * Inserts the string into this builder. * Inserting null will use the stored null text value. * * @param index the index to add at, must be valid * @param str the string to insert * @return this, to enable chaining * @throws IndexOutOfBoundsException if the index is invalid */ public StrBuilder insert(final int index, String str) { validateIndex(index); if (str == null) { str = nullText; } if (str != null) { final int strLen = str.length(); if (strLen > 0) { final int newSize = size + strLen; ensureCapacity(newSize); System.arraycopy(buffer, index, buffer, index + strLen, size - index); size = newSize; str.getChars(0, strLen, buffer, index); } } return this; } /** * Inserts the character array into this builder. * Inserting null will use the stored null text value. * * @param index the index to add at, must be valid * @param chars the char array to insert * @return this, to enable chaining * @throws IndexOutOfBoundsException if the index is invalid */ public StrBuilder insert(final int index, final char[] chars) { validateIndex(index); if (chars == null) { return insert(index, nullText); } final int len = chars.length; if (len > 0) { ensureCapacity(size + len); System.arraycopy(buffer, index, buffer, index + len, size - index); System.arraycopy(chars, 0, buffer, index, len); size += len; } return this; } /** * Inserts part of the character array into this builder. * Inserting null will use the stored null text value. * * @param index the index to add at, must be valid * @param chars the char array to insert * @param offset the offset into the character array to start at, must be valid * @param length the length of the character array part to copy, must be positive * @return this, to enable chaining * @throws IndexOutOfBoundsException if any index is invalid */ public StrBuilder insert(final int index, final char[] chars, final int offset, final int length) { validateIndex(index); if (chars == null) { return insert(index, nullText); } if (offset < 0 || offset > chars.length) { throw new StringIndexOutOfBoundsException("Invalid offset: " + offset); } if (length < 0 || offset + length > chars.length) { throw new StringIndexOutOfBoundsException("Invalid length: " + length); } if (length > 0) { ensureCapacity(size + length); System.arraycopy(buffer, index, buffer, index + length, size - index); System.arraycopy(chars, offset, buffer, index, length); size += length; } return this; } /** * Inserts the value into this builder. * * @param index the index to add at, must be valid * @param value the value to insert * @return this, to enable chaining * @throws IndexOutOfBoundsException if the index is invalid */ public StrBuilder insert(int index, final boolean value) { validateIndex(index); if (value) { ensureCapacity(size + 4); System.arraycopy(buffer, index, buffer, index + 4, size - index); buffer[index++] = 't'; buffer[index++] = 'r'; buffer[index++] = 'u'; buffer[index] = 'e'; size += 4; } else { ensureCapacity(size + 5); System.arraycopy(buffer, index, buffer, index + 5, size - index); buffer[index++] = 'f'; buffer[index++] = 'a'; buffer[index++] = 'l'; buffer[index++] = 's'; buffer[index] = 'e'; size += 5; } return this; } /** * Inserts the value into this builder. * * @param index the index to add at, must be valid * @param value the value to insert * @return this, to enable chaining * @throws IndexOutOfBoundsException if the index is invalid */ public StrBuilder insert(final int index, final char value) { validateIndex(index); ensureCapacity(size + 1); System.arraycopy(buffer, index, buffer, index + 1, size - index); buffer[index] = value; size++; return this; } /** * Inserts the value into this builder. * * @param index the index to add at, must be valid * @param value the value to insert * @return this, to enable chaining * @throws IndexOutOfBoundsException if the index is invalid */ public StrBuilder insert(final int index, final int value) { return insert(index, String.valueOf(value)); } /** * Inserts the value into this builder. * * @param index the index to add at, must be valid * @param value the value to insert * @return this, to enable chaining * @throws IndexOutOfBoundsException if the index is invalid */ public StrBuilder insert(final int index, final long value) { return insert(index, String.valueOf(value)); } /** * Inserts the value into this builder. * * @param index the index to add at, must be valid * @param value the value to insert * @return this, to enable chaining * @throws IndexOutOfBoundsException if the index is invalid */ public StrBuilder insert(final int index, final float value) { return insert(index, String.valueOf(value)); } /** * Inserts the value into this builder. * * @param index the index to add at, must be valid * @param value the value to insert * @return this, to enable chaining * @throws IndexOutOfBoundsException if the index is invalid */ public StrBuilder insert(final int index, final double value) { return insert(index, String.valueOf(value)); } //----------------------------------------------------------------------- /** * Internal method to delete a range without validation. * * @param startIndex the start index, must be valid * @param endIndex the end index (exclusive), must be valid * @param len the length, must be valid * @throws IndexOutOfBoundsException if any index is invalid */ private void deleteImpl(final int startIndex, final int endIndex, final int len) { System.arraycopy(buffer, endIndex, buffer, startIndex, size - endIndex); size -= len; } /** * Deletes the characters between the two specified indices. * * @param startIndex the start index, inclusive, must be valid * @param endIndex the end index, exclusive, must be valid except * that if too large it is treated as end of string * @return this, to enable chaining * @throws IndexOutOfBoundsException if the index is invalid */ public StrBuilder delete(final int startIndex, int endIndex) { endIndex = validateRange(startIndex, endIndex); final int len = endIndex - startIndex; if (len > 0) { deleteImpl(startIndex, endIndex, len); } return this; } //----------------------------------------------------------------------- /** * Deletes the character wherever it occurs in the builder. * * @param ch the character to delete * @return this, to enable chaining */ public StrBuilder deleteAll(final char ch) { for (int i = 0; i < size; i++) { if (buffer[i] == ch) { final int start = i; while (++i < size) { if (buffer[i] != ch) { break; } } final int len = i - start; deleteImpl(start, i, len); i -= len; } } return this; } /** * Deletes the character wherever it occurs in the builder. * * @param ch the character to delete * @return this, to enable chaining */ public StrBuilder deleteFirst(final char ch) { for (int i = 0; i < size; i++) { if (buffer[i] == ch) { deleteImpl(i, i + 1, 1); break; } } return this; } //----------------------------------------------------------------------- /** * Deletes the string wherever it occurs in the builder. * * @param str the string to delete, null causes no action * @return this, to enable chaining */ public StrBuilder deleteAll(final String str) { final int len = (str == null ? 0 : str.length()); if (len > 0) { int index = indexOf(str, 0); while (index >= 0) { deleteImpl(index, index + len, len); index = indexOf(str, index); } } return this; } /** * Deletes the string wherever it occurs in the builder. * * @param str the string to delete, null causes no action * @return this, to enable chaining */ public StrBuilder deleteFirst(final String str) { final int len = (str == null ? 0 : str.length()); if (len > 0) { final int index = indexOf(str, 0); if (index >= 0) { deleteImpl(index, index + len, len); } } return this; } //----------------------------------------------------------------------- /** * Deletes all parts of the builder that the matcher matches. *

* Matchers can be used to perform advanced deletion behaviour. * For example you could write a matcher to delete all occurrences * where the character 'a' is followed by a number. * * @param matcher the matcher to use to find the deletion, null causes no action * @return this, to enable chaining */ public StrBuilder deleteAll(final StrMatcher matcher) { return replace(matcher, null, 0, size, -1); } /** * Deletes the first match within the builder using the specified matcher. *

* Matchers can be used to perform advanced deletion behaviour. * For example you could write a matcher to delete * where the character 'a' is followed by a number. * * @param matcher the matcher to use to find the deletion, null causes no action * @return this, to enable chaining */ public StrBuilder deleteFirst(final StrMatcher matcher) { return replace(matcher, null, 0, size, 1); } //----------------------------------------------------------------------- /** * Internal method to delete a range without validation. * * @param startIndex the start index, must be valid * @param endIndex the end index (exclusive), must be valid * @param removeLen the length to remove (endIndex - startIndex), must be valid * @param insertStr the string to replace with, null means delete range * @param insertLen the length of the insert string, must be valid * @throws IndexOutOfBoundsException if any index is invalid */ private void replaceImpl(final int startIndex, final int endIndex, final int removeLen, final String insertStr, final int insertLen) { final int newSize = size - removeLen + insertLen; if (insertLen != removeLen) { ensureCapacity(newSize); System.arraycopy(buffer, endIndex, buffer, startIndex + insertLen, size - endIndex); size = newSize; } if (insertLen > 0) { insertStr.getChars(0, insertLen, buffer, startIndex); } } /** * Replaces a portion of the string builder with another string. * The length of the inserted string does not have to match the removed length. * * @param startIndex the start index, inclusive, must be valid * @param endIndex the end index, exclusive, must be valid except * that if too large it is treated as end of string * @param replaceStr the string to replace with, null means delete range * @return this, to enable chaining * @throws IndexOutOfBoundsException if the index is invalid */ public StrBuilder replace(final int startIndex, int endIndex, final String replaceStr) { endIndex = validateRange(startIndex, endIndex); final int insertLen = (replaceStr == null ? 0 : replaceStr.length()); replaceImpl(startIndex, endIndex, endIndex - startIndex, replaceStr, insertLen); return this; } //----------------------------------------------------------------------- /** * Replaces the search character with the replace character * throughout the builder. * * @param search the search character * @param replace the replace character * @return this, to enable chaining */ public StrBuilder replaceAll(final char search, final char replace) { if (search != replace) { for (int i = 0; i < size; i++) { if (buffer[i] == search) { buffer[i] = replace; } } } return this; } /** * Replaces the first instance of the search character with the * replace character in the builder. * * @param search the search character * @param replace the replace character * @return this, to enable chaining */ public StrBuilder replaceFirst(final char search, final char replace) { if (search != replace) { for (int i = 0; i < size; i++) { if (buffer[i] == search) { buffer[i] = replace; break; } } } return this; } //----------------------------------------------------------------------- /** * Replaces the search string with the replace string throughout the builder. * * @param searchStr the search string, null causes no action to occur * @param replaceStr the replace string, null is equivalent to an empty string * @return this, to enable chaining */ public StrBuilder replaceAll(final String searchStr, final String replaceStr) { final int searchLen = (searchStr == null ? 0 : searchStr.length()); if (searchLen > 0) { final int replaceLen = (replaceStr == null ? 0 : replaceStr.length()); int index = indexOf(searchStr, 0); while (index >= 0) { replaceImpl(index, index + searchLen, searchLen, replaceStr, replaceLen); index = indexOf(searchStr, index + replaceLen); } } return this; } /** * Replaces the first instance of the search string with the replace string. * * @param searchStr the search string, null causes no action to occur * @param replaceStr the replace string, null is equivalent to an empty string * @return this, to enable chaining */ public StrBuilder replaceFirst(final String searchStr, final String replaceStr) { final int searchLen = (searchStr == null ? 0 : searchStr.length()); if (searchLen > 0) { final int index = indexOf(searchStr, 0); if (index >= 0) { final int replaceLen = (replaceStr == null ? 0 : replaceStr.length()); replaceImpl(index, index + searchLen, searchLen, replaceStr, replaceLen); } } return this; } //----------------------------------------------------------------------- /** * Replaces all matches within the builder with the replace string. *

* Matchers can be used to perform advanced replace behaviour. * For example you could write a matcher to replace all occurrences * where the character 'a' is followed by a number. * * @param matcher the matcher to use to find the deletion, null causes no action * @param replaceStr the replace string, null is equivalent to an empty string * @return this, to enable chaining */ public StrBuilder replaceAll(final StrMatcher matcher, final String replaceStr) { return replace(matcher, replaceStr, 0, size, -1); } /** * Replaces the first match within the builder with the replace string. *

* Matchers can be used to perform advanced replace behaviour. * For example you could write a matcher to replace * where the character 'a' is followed by a number. * * @param matcher the matcher to use to find the deletion, null causes no action * @param replaceStr the replace string, null is equivalent to an empty string * @return this, to enable chaining */ public StrBuilder replaceFirst(final StrMatcher matcher, final String replaceStr) { return replace(matcher, replaceStr, 0, size, 1); } // ----------------------------------------------------------------------- /** * Advanced search and replaces within the builder using a matcher. *

* Matchers can be used to perform advanced behaviour. * For example you could write a matcher to delete all occurrences * where the character 'a' is followed by a number. * * @param matcher the matcher to use to find the deletion, null causes no action * @param replaceStr the string to replace the match with, null is a delete * @param startIndex the start index, inclusive, must be valid * @param endIndex the end index, exclusive, must be valid except * that if too large it is treated as end of string * @param replaceCount the number of times to replace, -1 for replace all * @return this, to enable chaining * @throws IndexOutOfBoundsException if start index is invalid */ public StrBuilder replace( final StrMatcher matcher, final String replaceStr, final int startIndex, int endIndex, final int replaceCount) { endIndex = validateRange(startIndex, endIndex); return replaceImpl(matcher, replaceStr, startIndex, endIndex, replaceCount); } /** * Replaces within the builder using a matcher. *

* Matchers can be used to perform advanced behaviour. * For example you could write a matcher to delete all occurrences * where the character 'a' is followed by a number. * * @param matcher the matcher to use to find the deletion, null causes no action * @param replaceStr the string to replace the match with, null is a delete * @param from the start index, must be valid * @param to the end index (exclusive), must be valid * @param replaceCount the number of times to replace, -1 for replace all * @return this, to enable chaining * @throws IndexOutOfBoundsException if any index is invalid */ private StrBuilder replaceImpl( final StrMatcher matcher, final String replaceStr, final int from, int to, int replaceCount) { if (matcher == null || size == 0) { return this; } final int replaceLen = (replaceStr == null ? 0 : replaceStr.length()); for (int i = from; i < to && replaceCount != 0; i++) { final char[] buf = buffer; final int removeLen = matcher.isMatch(buf, i, from, to); if (removeLen > 0) { replaceImpl(i, i + removeLen, removeLen, replaceStr, replaceLen); to = to - removeLen + replaceLen; i = i + replaceLen - 1; if (replaceCount > 0) { replaceCount--; } } } return this; } //----------------------------------------------------------------------- /** * Reverses the string builder placing each character in the opposite index. * * @return this, to enable chaining */ public StrBuilder reverse() { if (size == 0) { return this; } final int half = size / 2; final char[] buf = buffer; for (int leftIdx = 0, rightIdx = size - 1; leftIdx < half; leftIdx++, rightIdx--) { final char swap = buf[leftIdx]; buf[leftIdx] = buf[rightIdx]; buf[rightIdx] = swap; } return this; } //----------------------------------------------------------------------- /** * Trims the builder by removing characters less than or equal to a space * from the beginning and end. * * @return this, to enable chaining */ public StrBuilder trim() { if (size == 0) { return this; } int len = size; final char[] buf = buffer; int pos = 0; while (pos < len && buf[pos] <= ' ') { pos++; } while (pos < len && buf[len - 1] <= ' ') { len--; } if (len < size) { delete(len, size); } if (pos > 0) { delete(0, pos); } return this; } //----------------------------------------------------------------------- /** * Checks whether this builder starts with the specified string. *

* Note that this method handles null input quietly, unlike String. * * @param str the string to search for, null returns false * @return true if the builder starts with the string */ public boolean startsWith(final String str) { if (str == null) { return false; } final int len = str.length(); if (len == 0) { return true; } if (len > size) { return false; } for (int i = 0; i < len; i++) { if (buffer[i] != str.charAt(i)) { return false; } } return true; } /** * Checks whether this builder ends with the specified string. *

* Note that this method handles null input quietly, unlike String. * * @param str the string to search for, null returns false * @return true if the builder ends with the string */ public boolean endsWith(final String str) { if (str == null) { return false; } final int len = str.length(); if (len == 0) { return true; } if (len > size) { return false; } int pos = size - len; for (int i = 0; i < len; i++, pos++) { if (buffer[pos] != str.charAt(i)) { return false; } } return true; } //----------------------------------------------------------------------- /** * {@inheritDoc} */ @Override public CharSequence subSequence(final int startIndex, final int endIndex) { if (startIndex < 0) { throw new StringIndexOutOfBoundsException(startIndex); } if (endIndex > size) { throw new StringIndexOutOfBoundsException(endIndex); } if (startIndex > endIndex) { throw new StringIndexOutOfBoundsException(endIndex - startIndex); } return substring(startIndex, endIndex); } /** * Extracts a portion of this string builder as a string. * * @param start the start index, inclusive, must be valid * @return the new string * @throws IndexOutOfBoundsException if the index is invalid */ public String substring(final int start) { return substring(start, size); } /** * Extracts a portion of this string builder as a string. *

* Note: This method treats an endIndex greater than the length of the * builder as equal to the length of the builder, and continues * without error, unlike StringBuffer or String. * * @param startIndex the start index, inclusive, must be valid * @param endIndex the end index, exclusive, must be valid except * that if too large it is treated as end of string * @return the new string * @throws IndexOutOfBoundsException if the index is invalid */ public String substring(final int startIndex, int endIndex) { endIndex = validateRange(startIndex, endIndex); return new String(buffer, startIndex, endIndex - startIndex); } /** * Extracts the leftmost characters from the string builder without * throwing an exception. *

* This method extracts the left length characters from * the builder. If this many characters are not available, the whole * builder is returned. Thus the returned string may be shorter than the * length requested. * * @param length the number of characters to extract, negative returns empty string * @return the new string */ public String leftString(final int length) { if (length <= 0) { return ""; } else if (length >= size) { return new String(buffer, 0, size); } else { return new String(buffer, 0, length); } } /** * Extracts the rightmost characters from the string builder without * throwing an exception. *

* This method extracts the right length characters from * the builder. If this many characters are not available, the whole * builder is returned. Thus the returned string may be shorter than the * length requested. * * @param length the number of characters to extract, negative returns empty string * @return the new string */ public String rightString(final int length) { if (length <= 0) { return ""; } else if (length >= size) { return new String(buffer, 0, size); } else { return new String(buffer, size - length, length); } } /** * Extracts some characters from the middle of the string builder without * throwing an exception. *

* This method extracts length characters from the builder * at the specified index. * If the index is negative it is treated as zero. * If the index is greater than the builder size, it is treated as the builder size. * If the length is negative, the empty string is returned. * If insufficient characters are available in the builder, as much as possible is returned. * Thus the returned string may be shorter than the length requested. * * @param index the index to start at, negative means zero * @param length the number of characters to extract, negative returns empty string * @return the new string */ public String midString(int index, final int length) { if (index < 0) { index = 0; } if (length <= 0 || index >= size) { return ""; } if (size <= index + length) { return new String(buffer, index, size - index); } return new String(buffer, index, length); } //----------------------------------------------------------------------- /** * Checks if the string builder contains the specified char. * * @param ch the character to find * @return true if the builder contains the character */ public boolean contains(final char ch) { final char[] thisBuf = buffer; for (int i = 0; i < this.size; i++) { if (thisBuf[i] == ch) { return true; } } return false; } /** * Checks if the string builder contains the specified string. * * @param str the string to find * @return true if the builder contains the string */ public boolean contains(final String str) { return indexOf(str, 0) >= 0; } /** * Checks if the string builder contains a string matched using the * specified matcher. *

* Matchers can be used to perform advanced searching behaviour. * For example you could write a matcher to search for the character * 'a' followed by a number. * * @param matcher the matcher to use, null returns -1 * @return true if the matcher finds a match in the builder */ public boolean contains(final StrMatcher matcher) { return indexOf(matcher, 0) >= 0; } //----------------------------------------------------------------------- /** * Searches the string builder to find the first reference to the specified char. * * @param ch the character to find * @return the first index of the character, or -1 if not found */ public int indexOf(final char ch) { return indexOf(ch, 0); } /** * Searches the string builder to find the first reference to the specified char. * * @param ch the character to find * @param startIndex the index to start at, invalid index rounded to edge * @return the first index of the character, or -1 if not found */ public int indexOf(final char ch, int startIndex) { startIndex = (startIndex < 0 ? 0 : startIndex); if (startIndex >= size) { return -1; } final char[] thisBuf = buffer; for (int i = startIndex; i < size; i++) { if (thisBuf[i] == ch) { return i; } } return -1; } /** * Searches the string builder to find the first reference to the specified string. *

* Note that a null input string will return -1, whereas the JDK throws an exception. * * @param str the string to find, null returns -1 * @return the first index of the string, or -1 if not found */ public int indexOf(final String str) { return indexOf(str, 0); } /** * Searches the string builder to find the first reference to the specified * string starting searching from the given index. *

* Note that a null input string will return -1, whereas the JDK throws an exception. * * @param str the string to find, null returns -1 * @param startIndex the index to start at, invalid index rounded to edge * @return the first index of the string, or -1 if not found */ public int indexOf(final String str, int startIndex) { startIndex = (startIndex < 0 ? 0 : startIndex); if (str == null || startIndex >= size) { return -1; } final int strLen = str.length(); if (strLen == 1) { return indexOf(str.charAt(0), startIndex); } if (strLen == 0) { return startIndex; } if (strLen > size) { return -1; } final char[] thisBuf = buffer; final int len = size - strLen + 1; outer: for (int i = startIndex; i < len; i++) { for (int j = 0; j < strLen; j++) { if (str.charAt(j) != thisBuf[i + j]) { continue outer; } } return i; } return -1; } /** * Searches the string builder using the matcher to find the first match. *

* Matchers can be used to perform advanced searching behaviour. * For example you could write a matcher to find the character 'a' * followed by a number. * * @param matcher the matcher to use, null returns -1 * @return the first index matched, or -1 if not found */ public int indexOf(final StrMatcher matcher) { return indexOf(matcher, 0); } /** * Searches the string builder using the matcher to find the first * match searching from the given index. *

* Matchers can be used to perform advanced searching behaviour. * For example you could write a matcher to find the character 'a' * followed by a number. * * @param matcher the matcher to use, null returns -1 * @param startIndex the index to start at, invalid index rounded to edge * @return the first index matched, or -1 if not found */ public int indexOf(final StrMatcher matcher, int startIndex) { startIndex = (startIndex < 0 ? 0 : startIndex); if (matcher == null || startIndex >= size) { return -1; } final int len = size; final char[] buf = buffer; for (int i = startIndex; i < len; i++) { if (matcher.isMatch(buf, i, startIndex, len) > 0) { return i; } } return -1; } //----------------------------------------------------------------------- /** * Searches the string builder to find the last reference to the specified char. * * @param ch the character to find * @return the last index of the character, or -1 if not found */ public int lastIndexOf(final char ch) { return lastIndexOf(ch, size - 1); } /** * Searches the string builder to find the last reference to the specified char. * * @param ch the character to find * @param startIndex the index to start at, invalid index rounded to edge * @return the last index of the character, or -1 if not found */ public int lastIndexOf(final char ch, int startIndex) { startIndex = (startIndex >= size ? size - 1 : startIndex); if (startIndex < 0) { return -1; } for (int i = startIndex; i >= 0; i--) { if (buffer[i] == ch) { return i; } } return -1; } /** * Searches the string builder to find the last reference to the specified string. *

* Note that a null input string will return -1, whereas the JDK throws an exception. * * @param str the string to find, null returns -1 * @return the last index of the string, or -1 if not found */ public int lastIndexOf(final String str) { return lastIndexOf(str, size - 1); } /** * Searches the string builder to find the last reference to the specified * string starting searching from the given index. *

* Note that a null input string will return -1, whereas the JDK throws an exception. * * @param str the string to find, null returns -1 * @param startIndex the index to start at, invalid index rounded to edge * @return the last index of the string, or -1 if not found */ public int lastIndexOf(final String str, int startIndex) { startIndex = (startIndex >= size ? size - 1 : startIndex); if (str == null || startIndex < 0) { return -1; } final int strLen = str.length(); if (strLen > 0 && strLen <= size) { if (strLen == 1) { return lastIndexOf(str.charAt(0), startIndex); } outer: for (int i = startIndex - strLen + 1; i >= 0; i--) { for (int j = 0; j < strLen; j++) { if (str.charAt(j) != buffer[i + j]) { continue outer; } } return i; } } else if (strLen == 0) { return startIndex; } return -1; } /** * Searches the string builder using the matcher to find the last match. *

* Matchers can be used to perform advanced searching behaviour. * For example you could write a matcher to find the character 'a' * followed by a number. * * @param matcher the matcher to use, null returns -1 * @return the last index matched, or -1 if not found */ public int lastIndexOf(final StrMatcher matcher) { return lastIndexOf(matcher, size); } /** * Searches the string builder using the matcher to find the last * match searching from the given index. *

* Matchers can be used to perform advanced searching behaviour. * For example you could write a matcher to find the character 'a' * followed by a number. * * @param matcher the matcher to use, null returns -1 * @param startIndex the index to start at, invalid index rounded to edge * @return the last index matched, or -1 if not found */ public int lastIndexOf(final StrMatcher matcher, int startIndex) { startIndex = (startIndex >= size ? size - 1 : startIndex); if (matcher == null || startIndex < 0) { return -1; } final char[] buf = buffer; final int endIndex = startIndex + 1; for (int i = startIndex; i >= 0; i--) { if (matcher.isMatch(buf, i, 0, endIndex) > 0) { return i; } } return -1; } //----------------------------------------------------------------------- /** * Creates a tokenizer that can tokenize the contents of this builder. *

* This method allows the contents of this builder to be tokenized. * The tokenizer will be setup by default to tokenize on space, tab, * newline and formfeed (as per StringTokenizer). These values can be * changed on the tokenizer class, before retrieving the tokens. *

* The returned tokenizer is linked to this builder. You may intermix * calls to the buider and tokenizer within certain limits, however * there is no synchronization. Once the tokenizer has been used once, * it must be {@link StrTokenizer#reset() reset} to pickup the latest * changes in the builder. For example: *

     * StrBuilder b = new StrBuilder();
     * b.append("a b ");
     * StrTokenizer t = b.asTokenizer();
     * String[] tokens1 = t.getTokenArray();  // returns a,b
     * b.append("c d ");
     * String[] tokens2 = t.getTokenArray();  // returns a,b (c and d ignored)
     * t.reset();              // reset causes builder changes to be picked up
     * String[] tokens3 = t.getTokenArray();  // returns a,b,c,d
     * 
* In addition to simply intermixing appends and tokenization, you can also * call the set methods on the tokenizer to alter how it tokenizes. Just * remember to call reset when you want to pickup builder changes. *

* Calling {@link StrTokenizer#reset(String)} or {@link StrTokenizer#reset(char[])} * with a non-null value will break the link with the builder. * * @return a tokenizer that is linked to this builder */ public StrTokenizer asTokenizer() { return new StrBuilderTokenizer(); } //----------------------------------------------------------------------- /** * Gets the contents of this builder as a Reader. *

* This method allows the contents of the builder to be read * using any standard method that expects a Reader. *

* To use, simply create a StrBuilder, populate it with * data, call asReader, and then read away. *

* The internal character array is shared between the builder and the reader. * This allows you to append to the builder after creating the reader, * and the changes will be picked up. * Note however, that no synchronization occurs, so you must perform * all operations with the builder and the reader in one thread. *

* The returned reader supports marking, and ignores the flush method. * * @return a reader that reads from this builder */ public Reader asReader() { return new StrBuilderReader(); } //----------------------------------------------------------------------- /** * Gets this builder as a Writer that can be written to. *

* This method allows you to populate the contents of the builder * using any standard method that takes a Writer. *

* To use, simply create a StrBuilder, * call asWriter, and populate away. The data is available * at any time using the methods of the StrBuilder. *

* The internal character array is shared between the builder and the writer. * This allows you to intermix calls that append to the builder and * write using the writer and the changes will be occur correctly. * Note however, that no synchronization occurs, so you must perform * all operations with the builder and the writer in one thread. *

* The returned writer ignores the close and flush methods. * * @return a writer that populates this builder */ public Writer asWriter() { return new StrBuilderWriter(); } /** * Appends current contents of this StrBuilder to the * provided {@link Appendable}. *

* This method tries to avoid doing any extra copies of contents. * * @param appendable the appendable to append data to * @throws IOException if an I/O error occurs * * @see #readFrom(Readable) */ public void appendTo(final Appendable appendable) throws IOException { if (appendable instanceof Writer) { ((Writer) appendable).write(buffer, 0, size); } else if (appendable instanceof StringBuilder) { ((StringBuilder) appendable).append(buffer, 0, size); } else if (appendable instanceof StringBuffer) { ((StringBuffer) appendable).append(buffer, 0, size); } else if (appendable instanceof CharBuffer) { ((CharBuffer) appendable).put(buffer, 0, size); } else { appendable.append(this); } } //----------------------------------------------------------------------- // /** // * Gets a String version of the string builder by calling the internal // * constructor of String by reflection. // *

// * WARNING: You must not use the StrBuilder after calling this method // * as the buffer is now shared with the String object. To ensure this, // * the internal character array is set to null, so you will get // * NullPointerExceptions on all method calls. // * // * @return the builder as a String // */ // public String toSharedString() { // try { // Constructor con = String.class.getDeclaredConstructor( // new Class[] {int.class, int.class, char[].class}); // con.setAccessible(true); // char[] buffer = buf; // buf = null; // size = -1; // nullText = null; // return (String) con.newInstance( // new Object[] {Integer.valueOf(0), Integer.valueOf(size), buffer}); // // } catch (Exception ex) { // ex.printStackTrace(); // throw new UnsupportedOperationException("StrBuilder.toSharedString is unsupported: " + ex.getMessage()); // } // } //----------------------------------------------------------------------- /** * Checks the contents of this builder against another to see if they * contain the same character content ignoring case. * * @param other the object to check, null returns false * @return true if the builders contain the same characters in the same order */ public boolean equalsIgnoreCase(final StrBuilder other) { if (this == other) { return true; } if (this.size != other.size) { return false; } final char[] thisBuf = this.buffer; final char[] otherBuf = other.buffer; for (int i = size - 1; i >= 0; i--) { final char c1 = thisBuf[i]; final char c2 = otherBuf[i]; if (c1 != c2 && Character.toUpperCase(c1) != Character.toUpperCase(c2)) { return false; } } return true; } /** * Checks the contents of this builder against another to see if they * contain the same character content. * * @param other the object to check, null returns false * @return true if the builders contain the same characters in the same order */ public boolean equals(final StrBuilder other) { if (this == other) { return true; } if (other == null) { return false; } if (this.size != other.size) { return false; } final char[] thisBuf = this.buffer; final char[] otherBuf = other.buffer; for (int i = size - 1; i >= 0; i--) { if (thisBuf[i] != otherBuf[i]) { return false; } } return true; } /** * Checks the contents of this builder against another to see if they * contain the same character content. * * @param obj the object to check, null returns false * @return true if the builders contain the same characters in the same order */ @Override public boolean equals(final Object obj) { return obj instanceof StrBuilder && equals((StrBuilder) obj); } /** * Gets a suitable hash code for this builder. * * @return a hash code */ @Override public int hashCode() { final char[] buf = buffer; int hash = 0; for (int i = size - 1; i >= 0; i--) { hash = 31 * hash + buf[i]; } return hash; } //----------------------------------------------------------------------- /** * Gets a String version of the string builder, creating a new instance * each time the method is called. *

* Note that unlike StringBuffer, the string version returned is * independent of the string builder. * * @return the builder as a String */ @Override public String toString() { return new String(buffer, 0, size); } /** * Gets a StringBuffer version of the string builder, creating a * new instance each time the method is called. * * @return the builder as a StringBuffer */ public StringBuffer toStringBuffer() { return new StringBuffer(size).append(buffer, 0, size); } /** * Gets a StringBuilder version of the string builder, creating a * new instance each time the method is called. * * @return the builder as a StringBuilder */ public StringBuilder toStringBuilder() { return new StringBuilder(size).append(buffer, 0, size); } /** * Implement the {@link Builder} interface. * @return the builder as a String * @see #toString() */ @Override public String build() { return toString(); } //----------------------------------------------------------------------- /** * Validates parameters defining a range of the builder. * * @param startIndex the start index, inclusive, must be valid * @param endIndex the end index, exclusive, must be valid except * that if too large it is treated as end of string * @return the new string * @throws IndexOutOfBoundsException if the index is invalid */ protected int validateRange(final int startIndex, int endIndex) { if (startIndex < 0) { throw new StringIndexOutOfBoundsException(startIndex); } if (endIndex > size) { endIndex = size; } if (startIndex > endIndex) { throw new StringIndexOutOfBoundsException("end < start"); } return endIndex; } /** * Validates parameters defining a single index in the builder. * * @param index the index, must be valid * @throws IndexOutOfBoundsException if the index is invalid */ protected void validateIndex(final int index) { if (index < 0 || index > size) { throw new StringIndexOutOfBoundsException(index); } } //----------------------------------------------------------------------- /** * Inner class to allow StrBuilder to operate as a tokenizer. */ class StrBuilderTokenizer extends StrTokenizer { /** * Default constructor. */ StrBuilderTokenizer() { super(); } /** {@inheritDoc} */ @Override protected List tokenize(final char[] chars, final int offset, final int count) { if (chars == null) { return super.tokenize( StrBuilder.this.buffer, 0, StrBuilder.this.size()); } return super.tokenize(chars, offset, count); } /** {@inheritDoc} */ @Override public String getContent() { final String str = super.getContent(); if (str == null) { return StrBuilder.this.toString(); } return str; } } //----------------------------------------------------------------------- /** * Inner class to allow StrBuilder to operate as a reader. */ class StrBuilderReader extends Reader { /** The current stream position. */ private int pos; /** The last mark position. */ private int mark; /** * Default constructor. */ StrBuilderReader() { super(); } /** {@inheritDoc} */ @Override public void close() { // do nothing } /** {@inheritDoc} */ @Override public int read() { if (!ready()) { return -1; } return StrBuilder.this.charAt(pos++); } /** {@inheritDoc} */ @Override public int read(final char[] b, final int off, int len) { if (off < 0 || len < 0 || off > b.length || (off + len) > b.length || (off + len) < 0) { throw new IndexOutOfBoundsException(); } if (len == 0) { return 0; } if (pos >= StrBuilder.this.size()) { return -1; } if (pos + len > size()) { len = StrBuilder.this.size() - pos; } StrBuilder.this.getChars(pos, pos + len, b, off); pos += len; return len; } /** {@inheritDoc} */ @Override public long skip(long n) { if (pos + n > StrBuilder.this.size()) { n = StrBuilder.this.size() - pos; } if (n < 0) { return 0; } pos += n; return n; } /** {@inheritDoc} */ @Override public boolean ready() { return pos < StrBuilder.this.size(); } /** {@inheritDoc} */ @Override public boolean markSupported() { return true; } /** {@inheritDoc} */ @Override public void mark(final int readAheadLimit) { mark = pos; } /** {@inheritDoc} */ @Override public void reset() { pos = mark; } } //----------------------------------------------------------------------- /** * Inner class to allow StrBuilder to operate as a writer. */ class StrBuilderWriter extends Writer { /** * Default constructor. */ StrBuilderWriter() { super(); } /** {@inheritDoc} */ @Override public void close() { // do nothing } /** {@inheritDoc} */ @Override public void flush() { // do nothing } /** {@inheritDoc} */ @Override public void write(final int c) { StrBuilder.this.append((char) c); } /** {@inheritDoc} */ @Override public void write(final char[] cbuf) { StrBuilder.this.append(cbuf); } /** {@inheritDoc} */ @Override public void write(final char[] cbuf, final int off, final int len) { StrBuilder.this.append(cbuf, off, len); } /** {@inheritDoc} */ @Override public void write(final String str) { StrBuilder.this.append(str); } /** {@inheritDoc} */ @Override public void write(final String str, final int off, final int len) { StrBuilder.this.append(str, off, len); } } }





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