de.schildbach.pte.util.WordUtils Maven / Gradle / Ivy
/*
* 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 de.schildbach.pte.util;
/**
*
* Operations on Strings that contain words.
*
*
*
* This class tries to handle null input gracefully. An exception will not be thrown for a
* null input. Each method documents its behaviour in more detail.
*
*
* @since 2.0
* @version $Id$
*/
public class WordUtils {
/**
*
* WordUtils instances should NOT be constructed in standard programming. Instead, the class
* should be used as WordUtils.wrap("foo bar", 20);.
*
*
*
* This constructor is public to permit tools that require a JavaBean instance to operate.
*
*/
public WordUtils() {
super();
}
// Empty checks, taken from StringUtils
// -----------------------------------------------------------------------
/**
*
* Checks if a CharSequence is empty ("") or null.
*
*
*
* StringUtils.isEmpty(null) = true
* StringUtils.isEmpty("") = true
* StringUtils.isEmpty(" ") = false
* StringUtils.isEmpty("bob") = false
* StringUtils.isEmpty(" bob ") = false
*
*
*
* NOTE: This method changed in Lang version 2.0. It no longer trims the CharSequence. That functionality
* is available in isBlank().
*
*
* @param cs
* the CharSequence to check, may be null
* @return {@code true} if the CharSequence is empty or null
* @since 3.0 Changed signature from isEmpty(String) to isEmpty(CharSequence)
*/
public static boolean isEmpty(final CharSequence cs) {
return cs == null || cs.length() == 0;
}
public static String capitalizeFirst(final String str) {
if (str == null || str.length() <= 0)
return str;
if (str.length() == 1)
return str.toUpperCase();
return str.substring(0, 1).toUpperCase() + str.substring(1);
}
// stripped:
// public static String wrap(final String str, final int wrapLength)
// public static String wrap(final String str, int wrapLength, String newLineStr, final boolean
// wrapLongWords)
// Capitalizing
// -----------------------------------------------------------------------
/**
*
* Capitalizes all the whitespace separated words in a String. Only the first letter of each word is
* changed. To convert the rest of each word to lowercase at the same time, use
* {@link #capitalizeFully(String)}.
*
*
*
* Whitespace is defined by {@link Character#isWhitespace(char)}. A null input String returns
* null. Capitalization uses the Unicode title case, normally equivalent to upper case.
*
*
*
* WordUtils.capitalize(null) = null
* WordUtils.capitalize("") = ""
* WordUtils.capitalize("i am FINE") = "I Am FINE"
*
*
* @param str
* the String to capitalize, may be null
* @return capitalized String, null if null String input
* @see #uncapitalize(String)
* @see #capitalizeFully(String)
*/
public static String capitalize(final String str) {
return capitalize(str, null);
}
/**
*
* Capitalizes all the delimiter separated words in a String. Only the first letter of each word is
* changed. To convert the rest of each word to lowercase at the same time, use
* {@link #capitalizeFully(String, char[])}.
*
*
*
* The delimiters represent a set of characters understood to separate words. The first string character
* and the first non-delimiter character after a delimiter will be capitalized.
*
*
*
* A null input String returns null. Capitalization uses the Unicode title case,
* normally equivalent to upper case.
*
*
*
* WordUtils.capitalize(null, *) = null
* WordUtils.capitalize("", *) = ""
* WordUtils.capitalize(*, new char[0]) = *
* WordUtils.capitalize("i am fine", null) = "I Am Fine"
* WordUtils.capitalize("i aM.fine", {'.'}) = "I aM.Fine"
*
*
* @param str
* the String to capitalize, may be null
* @param delimiters
* set of characters to determine capitalization, null means whitespace
* @return capitalized String, null if null String input
* @see #uncapitalize(String)
* @see #capitalizeFully(String)
* @since 2.1
*/
public static String capitalize(final String str, final char... delimiters) {
final int delimLen = delimiters == null ? -1 : delimiters.length;
if (isEmpty(str) || delimLen == 0) {
return str;
}
final char[] buffer = str.toCharArray();
boolean capitalizeNext = true;
for (int i = 0; i < buffer.length; i++) {
final char ch = buffer[i];
if (isDelimiter(ch, delimiters)) {
capitalizeNext = true;
} else if (capitalizeNext) {
buffer[i] = Character.toTitleCase(ch);
capitalizeNext = false;
}
}
return new String(buffer);
}
// -----------------------------------------------------------------------
/**
*
* Converts all the whitespace separated words in a String into capitalized words, that is each word is
* made up of a titlecase character and then a series of lowercase characters.
*
*
*
* Whitespace is defined by {@link Character#isWhitespace(char)}. A null input String returns
* null. Capitalization uses the Unicode title case, normally equivalent to upper case.
*
*
*
* WordUtils.capitalizeFully(null) = null
* WordUtils.capitalizeFully("") = ""
* WordUtils.capitalizeFully("i am FINE") = "I Am Fine"
*
*
* @param str
* the String to capitalize, may be null
* @return capitalized String, null if null String input
*/
public static String capitalizeFully(final String str) {
return capitalizeFully(str, null);
}
/**
*
* Converts all the delimiter separated words in a String into capitalized words, that is each word is
* made up of a titlecase character and then a series of lowercase characters.
*
*
*
* The delimiters represent a set of characters understood to separate words. The first string character
* and the first non-delimiter character after a delimiter will be capitalized.
*
*
*
* A null input String returns null. Capitalization uses the Unicode title case,
* normally equivalent to upper case.
*
*
*
* WordUtils.capitalizeFully(null, *) = null
* WordUtils.capitalizeFully("", *) = ""
* WordUtils.capitalizeFully(*, null) = *
* WordUtils.capitalizeFully(*, new char[0]) = *
* WordUtils.capitalizeFully("i aM.fine", {'.'}) = "I am.Fine"
*
*
* @param str
* the String to capitalize, may be null
* @param delimiters
* set of characters to determine capitalization, null means whitespace
* @return capitalized String, null if null String input
* @since 2.1
*/
public static String capitalizeFully(String str, final char... delimiters) {
final int delimLen = delimiters == null ? -1 : delimiters.length;
if (isEmpty(str) || delimLen == 0) {
return str;
}
str = str.toLowerCase();
return capitalize(str, delimiters);
}
// -----------------------------------------------------------------------
/**
*
* Uncapitalizes all the whitespace separated words in a String. Only the first letter of each word is
* changed.
*
*
*
* Whitespace is defined by {@link Character#isWhitespace(char)}. A null input String returns
* null.
*
*
*
* WordUtils.uncapitalize(null) = null
* WordUtils.uncapitalize("") = ""
* WordUtils.uncapitalize("I Am FINE") = "i am fINE"
*
*
* @param str
* the String to uncapitalize, may be null
* @return uncapitalized String, null if null String input
* @see #capitalize(String)
*/
public static String uncapitalize(final String str) {
return uncapitalize(str, null);
}
/**
*
* Uncapitalizes all the whitespace separated words in a String. Only the first letter of each word is
* changed.
*
*
*
* The delimiters represent a set of characters understood to separate words. The first string character
* and the first non-delimiter character after a delimiter will be uncapitalized.
*
*
*
* Whitespace is defined by {@link Character#isWhitespace(char)}. A null input String returns
* null.
*
*
*
* WordUtils.uncapitalize(null, *) = null
* WordUtils.uncapitalize("", *) = ""
* WordUtils.uncapitalize(*, null) = *
* WordUtils.uncapitalize(*, new char[0]) = *
* WordUtils.uncapitalize("I AM.FINE", {'.'}) = "i AM.fINE"
*
*
* @param str
* the String to uncapitalize, may be null
* @param delimiters
* set of characters to determine uncapitalization, null means whitespace
* @return uncapitalized String, null if null String input
* @see #capitalize(String)
* @since 2.1
*/
public static String uncapitalize(final String str, final char... delimiters) {
final int delimLen = delimiters == null ? -1 : delimiters.length;
if (isEmpty(str) || delimLen == 0) {
return str;
}
final char[] buffer = str.toCharArray();
boolean uncapitalizeNext = true;
for (int i = 0; i < buffer.length; i++) {
final char ch = buffer[i];
if (isDelimiter(ch, delimiters)) {
uncapitalizeNext = true;
} else if (uncapitalizeNext) {
buffer[i] = Character.toLowerCase(ch);
uncapitalizeNext = false;
}
}
return new String(buffer);
}
// -----------------------------------------------------------------------
/**
*
* Swaps the case of a String using a word based algorithm.
*
*
*
* - Upper case character converts to Lower case
* - Title case character converts to Lower case
* - Lower case character after Whitespace or at start converts to Title case
* - Other Lower case character converts to Upper case
*
*
*
* Whitespace is defined by {@link Character#isWhitespace(char)}. A null input String returns
* null.
*
*
*
* StringUtils.swapCase(null) = null
* StringUtils.swapCase("") = ""
* StringUtils.swapCase("The dog has a BONE") = "tHE DOG HAS A bone"
*
*
* @param str
* the String to swap case, may be null
* @return the changed String, null if null String input
*/
public static String swapCase(final String str) {
if (isEmpty(str)) {
return str;
}
final char[] buffer = str.toCharArray();
boolean whitespace = true;
for (int i = 0; i < buffer.length; i++) {
final char ch = buffer[i];
if (Character.isUpperCase(ch)) {
buffer[i] = Character.toLowerCase(ch);
whitespace = false;
} else if (Character.isTitleCase(ch)) {
buffer[i] = Character.toLowerCase(ch);
whitespace = false;
} else if (Character.isLowerCase(ch)) {
if (whitespace) {
buffer[i] = Character.toTitleCase(ch);
whitespace = false;
} else {
buffer[i] = Character.toUpperCase(ch);
}
} else {
whitespace = Character.isWhitespace(ch);
}
}
return new String(buffer);
}
// -----------------------------------------------------------------------
/**
*
* Extracts the initial letters from each word in the String.
*
*
*
* The first letter of the string and all first letters after whitespace are returned as a new string.
* Their case is not changed.
*
*
*
* Whitespace is defined by {@link Character#isWhitespace(char)}. A null input String returns
* null.
*
*
*
* WordUtils.initials(null) = null
* WordUtils.initials("") = ""
* WordUtils.initials("Ben John Lee") = "BJL"
* WordUtils.initials("Ben J.Lee") = "BJ"
*
*
* @param str
* the String to get initials from, may be null
* @return String of initial letters, null if null String input
* @see #initials(String,char[])
* @since 2.2
*/
public static String initials(final String str) {
return initials(str, null);
}
/**
*
* Extracts the initial letters from each word in the String.
*
*
*
* The first letter of the string and all first letters after the defined delimiters are returned as a new
* string. Their case is not changed.
*
*
*
* If the delimiters array is null, then Whitespace is used. Whitespace is defined by
* {@link Character#isWhitespace(char)}. A null input String returns null. An
* empty delimiter array returns an empty String.
*
*
*
* WordUtils.initials(null, *) = null
* WordUtils.initials("", *) = ""
* WordUtils.initials("Ben John Lee", null) = "BJL"
* WordUtils.initials("Ben J.Lee", null) = "BJ"
* WordUtils.initials("Ben J.Lee", [' ','.']) = "BJL"
* WordUtils.initials(*, new char[0]) = ""
*
*
* @param str
* the String to get initials from, may be null
* @param delimiters
* set of characters to determine words, null means whitespace
* @return String of initial letters, null if null String input
* @see #initials(String)
* @since 2.2
*/
public static String initials(final String str, final char... delimiters) {
if (isEmpty(str)) {
return str;
}
if (delimiters != null && delimiters.length == 0) {
return "";
}
final int strLen = str.length();
final char[] buf = new char[strLen / 2 + 1];
int count = 0;
boolean lastWasGap = true;
for (int i = 0; i < strLen; i++) {
final char ch = str.charAt(i);
if (isDelimiter(ch, delimiters)) {
lastWasGap = true;
} else if (lastWasGap) {
buf[count++] = ch;
lastWasGap = false;
} else {
continue; // ignore ch
}
}
return new String(buf, 0, count);
}
// -----------------------------------------------------------------------
/**
* Is the character a delimiter.
*
* @param ch
* the character to check
* @param delimiters
* the delimiters
* @return true if it is a delimiter
*/
private static boolean isDelimiter(final char ch, final char[] delimiters) {
if (delimiters == null) {
return Character.isWhitespace(ch);
}
for (final char delimiter : delimiters) {
if (ch == delimiter) {
return true;
}
}
return false;
}
}