fr.ght1pc9kc.juery.basic.common.lang3.StringUtils 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 fr.ght1pc9kc.juery.basic.common.lang3;
public class StringUtils {
private static final int NOT_FOUND = -1;
/**
* Checks if a CharSequence is empty (""), null or whitespace only.
*
* Whitespace is defined by {@link Character#isWhitespace(char)}.
*
*
* StringUtils.isBlank(null) = true
* StringUtils.isBlank("") = true
* StringUtils.isBlank(" ") = true
* StringUtils.isBlank("bob") = false
* StringUtils.isBlank(" bob ") = false
*
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if the CharSequence is null, empty or whitespace only
* @since 2.0
* @since 3.0 Changed signature from isBlank(String) to isBlank(CharSequence)
*/
public static boolean isBlank(final CharSequence cs) {
final int strLen = length(cs);
if (strLen == 0) {
return true;
}
for (int i = 0; i < strLen; i++) {
if (!Character.isWhitespace(cs.charAt(i))) {
return false;
}
}
return true;
}
/**
* Gets a CharSequence length or {@code 0} if the CharSequence is
* {@code null}.
*
* @param cs a CharSequence or {@code null}
* @return CharSequence length or {@code 0} if the CharSequence is
* {@code null}.
* @since 2.4
* @since 3.0 Changed signature from length(String) to length(CharSequence)
*/
public static int length(final CharSequence cs) {
return cs == null ? 0 : cs.length();
}
// Empty checks
//-----------------------------------------------------------------------
/**
* 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;
}
// Contains
//-----------------------------------------------------------------------
/**
* Checks if CharSequence contains a search character, handling {@code null}.
* This method uses {@link String#indexOf(int)} if possible.
*
* A {@code null} or empty ("") CharSequence will return {@code false}.
*
*
* StringUtils.contains(null, *) = false
* StringUtils.contains("", *) = false
* StringUtils.contains("abc", 'a') = true
* StringUtils.contains("abc", 'z') = false
*
*
* @param seq the CharSequence to check, may be null
* @param searchChar the character to find
* @return true if the CharSequence contains the search character,
* false if not or {@code null} string input
* @since 2.0
* @since 3.0 Changed signature from contains(String, int) to contains(CharSequence, int)
*/
public static boolean contains(final CharSequence seq, final int searchChar) {
if (isEmpty(seq)) {
return false;
}
return indexOf(seq, searchChar, 0) >= 0;
}
/**
* Checks if the CharSequence contains only Unicode digits.
* A decimal point is not a Unicode digit and returns false.
*
* {@code null} will return {@code false}.
* An empty CharSequence (length()=0) will return {@code false}.
*
* Note that the method does not allow for a leading sign, either positive or negative.
* Also, if a String passes the numeric test, it may still generate a NumberFormatException
* when parsed by Integer.parseInt or Long.parseLong, e.g. if the value is outside the range
* for int or long respectively.
*
*
* StringUtils.isNumeric(null) = false
* StringUtils.isNumeric("") = false
* StringUtils.isNumeric(" ") = false
* StringUtils.isNumeric("123") = true
* StringUtils.isNumeric("\u0967\u0968\u0969") = true
* StringUtils.isNumeric("12 3") = false
* StringUtils.isNumeric("ab2c") = false
* StringUtils.isNumeric("12-3") = false
* StringUtils.isNumeric("12.3") = false
* StringUtils.isNumeric("-123") = false
* StringUtils.isNumeric("+123") = false
*
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if only contains digits, and is non-null
* @since 3.0 Changed signature from isNumeric(String) to isNumeric(CharSequence)
* @since 3.0 Changed "" to return false and not true
*/
public static boolean isNumeric(final CharSequence cs) {
if (isEmpty(cs)) {
return false;
}
final int sz = cs.length();
for (int i = 0; i < sz; i++) {
if (!Character.isDigit(cs.charAt(i))) {
return false;
}
}
return true;
}
/**
* Returns the index within {@code cs} of the first occurrence of the
* specified character, starting the search at the specified index.
*
* If a character with value {@code searchChar} occurs in the
* character sequence represented by the {@code cs}
* object at an index no smaller than {@code start}, then
* the index of the first such occurrence is returned. For values
* of {@code searchChar} in the range from 0 to 0xFFFF (inclusive),
* this is the smallest value k such that:
*
* (this.charAt(k) == searchChar) && (k >= start)
*
* is true. For other values of {@code searchChar}, it is the
* smallest value k such that:
*
* (this.codePointAt(k) == searchChar) && (k >= start)
*
* is true. In either case, if no such character occurs inm {@code cs}
* at or after position {@code start}, then
* {@code -1} is returned.
*
*
* There is no restriction on the value of {@code start}. If it
* is negative, it has the same effect as if it were zero: the entire
* {@code CharSequence} may be searched. If it is greater than
* the length of {@code cs}, it has the same effect as if it were
* equal to the length of {@code cs}: {@code -1} is returned.
*
*
All indices are specified in {@code char} values
* (Unicode code units).
*
* @param cs the {@code CharSequence} to be processed, not null
* @param searchChar the char to be searched for
* @param start the start index, negative starts at the string start
* @return the index where the search char was found, -1 if not found
* @since 3.6 updated to behave more like {@code String}
*/
static int indexOf(final CharSequence cs, final int searchChar, int start) {
if (cs instanceof String) {
return ((String) cs).indexOf(searchChar, start);
}
final int sz = cs.length();
if (start < 0) {
start = 0;
}
if (searchChar < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
for (int i = start; i < sz; i++) {
if (cs.charAt(i) == searchChar) {
return i;
}
}
}
//supplementary characters (LANG1300)
if (searchChar <= Character.MAX_CODE_POINT) {
final char[] chars = Character.toChars(searchChar);
for (int i = start; i < sz - 1; i++) {
final char high = cs.charAt(i);
final char low = cs.charAt(i + 1);
if (high == chars[0] && low == chars[1]) {
return i;
}
}
}
return NOT_FOUND;
}
}