com.xingyuv.captcha.util.StringUtils Maven / Gradle / Ivy
/*
*Copyright © 2018 anji-plus
*安吉加加信息技术有限公司
*http://www.anji-plus.com
*All rights reserved.
*/
package com.xingyuv.captcha.util;
import java.util.Objects;
public class StringUtils {
/**
* The empty String "".
*
* @since 2.0
*/
public static final String EMPTY = "";
/**
* Represents a failed index search.
*
* @since 2.1
*/
public static final int INDEX_NOT_FOUND = -1;
/**
* The maximum size to which the padding constant(s) can expand.
*/
private static final int PAD_LIMIT = 8192;
/**
* StringUtils instances should NOT be constructed in
* standard programming. Instead, the class should be used as
* StringUtils.trim(" foo ");.
*
* This constructor is public to permit tools that require a JavaBean
* instance to operate.
*/
public StringUtils() {
super();
}
// Empty checks
//-----------------------------------------------------------------------
/**
* Checks if a String 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 String.
* That functionality is available in isBlank().
*
* @param str the String to check, may be null
* @return true if the String is empty or null
*/
public static boolean isEmpty(String str) {
return str == null || str.length() == 0;
}
/**
* Checks if a String is not empty ("") and not null.
*
*
* StringUtils.isNotEmpty(null) = false
* StringUtils.isNotEmpty("") = false
* StringUtils.isNotEmpty(" ") = true
* StringUtils.isNotEmpty("bob") = true
* StringUtils.isNotEmpty(" bob ") = true
*
*
* @param str the String to check, may be null
* @return true if the String is not empty and not null
*/
public static boolean isNotEmpty(String str) {
return !StringUtils.isEmpty(str);
}
/**
* Checks if a String is whitespace, empty ("") or null.
*
*
* StringUtils.isBlank(null) = true
* StringUtils.isBlank("null") = true
* StringUtils.isBlank("") = true
* StringUtils.isBlank(" ") = true
* StringUtils.isBlank("bob") = false
* StringUtils.isBlank(" bob ") = false
*
*
* @param str the String to check, may be null
* @return true if the String is null, empty or whitespace
* @since 2.0
*/
public static boolean isBlank(String str) {
int strLen;
if (str == null || (strLen = str.length()) == 0) {
return true;
}
if (equals("null", str.trim().toLowerCase())) {
return true;
}
for (int i = 0; i < strLen; i++) {
if ((!Character.isWhitespace(str.charAt(i)))) {
return false;
}
}
return true;
}
/**
* Checks if a String is not empty (""), not null and not whitespace only.
*
*
* StringUtils.isNotBlank(null) = false
* StringUtils.isNotBlank("null") = false
* StringUtils.isNotBlank("") = false
* StringUtils.isNotBlank(" ") = false
* StringUtils.isNotBlank("bob") = true
* StringUtils.isNotBlank(" bob ") = true
*
*
* @param str the String to check, may be null
* @return true if the String is
* not empty and not null and not whitespace
* @since 2.0
*/
public static boolean isNotBlank(String str) {
return !StringUtils.isBlank(str);
}
// Trim
//-----------------------------------------------------------------------
/**
* Removes control characters (char <= 32) from both
* ends of this String, handling null by returning
* an empty String ("").
*
*
* StringUtils.clean(null) = ""
* StringUtils.clean("") = ""
* StringUtils.clean("abc") = "abc"
* StringUtils.clean(" abc ") = "abc"
* StringUtils.clean(" ") = ""
*
*
* @param str the String to clean, may be null
* @return the trimmed text, never null
* @see java.lang.String#trim()
* @deprecated Use the clearer named {@link #trimToEmpty(String)}.
* Method will be removed in Commons Lang 3.0.
*/
public static String clean(String str) {
return str == null ? EMPTY : str.trim();
}
/**
* Removes control characters (char <= 32) from both
* ends of this String, handling null by returning
* null.
*
* The String is trimmed using {@link String#trim()}.
* Trim removes start and end characters <= 32.
* To strip whitespace use {@link #strip(String)}.
*
* To trim your choice of characters, use the
* {@link #strip(String, String)} methods.
*
*
* StringUtils.trim(null) = null
* StringUtils.trim("") = ""
* StringUtils.trim(" ") = ""
* StringUtils.trim("abc") = "abc"
* StringUtils.trim(" abc ") = "abc"
*
*
* @param str the String to be trimmed, may be null
* @return the trimmed string, null if null String input
*/
public static String trim(String str) {
return str == null ? null : str.trim();
}
/**
* Removes control characters (char <= 32) from both
* ends of this String returning null if the String is
* empty ("") after the trim or if it is null.
*
*
The String is trimmed using {@link String#trim()}.
* Trim removes start and end characters <= 32.
* To strip whitespace use {@link #stripToNull(String)}.
*
*
* StringUtils.trimToNull(null) = null
* StringUtils.trimToNull("") = null
* StringUtils.trimToNull(" ") = null
* StringUtils.trimToNull("abc") = "abc"
* StringUtils.trimToNull(" abc ") = "abc"
*
*
* @param str the String to be trimmed, may be null
* @return the trimmed String,
* null if only chars <= 32, empty or null String input
* @since 2.0
*/
public static String trimToNull(String str) {
String ts = trim(str);
return isEmpty(ts) ? null : ts;
}
/**
* Removes control characters (char <= 32) from both
* ends of this String returning an empty String ("") if the String
* is empty ("") after the trim or if it is null.
*
*
The String is trimmed using {@link String#trim()}.
* Trim removes start and end characters <= 32.
* To strip whitespace use {@link #stripToEmpty(String)}.
*
*
* StringUtils.trimToEmpty(null) = ""
* StringUtils.trimToEmpty("") = ""
* StringUtils.trimToEmpty(" ") = ""
* StringUtils.trimToEmpty("abc") = "abc"
* StringUtils.trimToEmpty(" abc ") = "abc"
*
*
* @param str the String to be trimmed, may be null
* @return the trimmed String, or an empty String if null input
* @since 2.0
*/
public static String trimToEmpty(String str) {
return str == null ? EMPTY : str.trim();
}
// Stripping
//-----------------------------------------------------------------------
/**
* Strips whitespace from the start and end of a String.
*
* This is similar to {@link #trim(String)} but removes whitespace.
* Whitespace is defined by {@link Character#isWhitespace(char)}.
*
* A null input String returns null.
*
*
* StringUtils.strip(null) = null
* StringUtils.strip("") = ""
* StringUtils.strip(" ") = ""
* StringUtils.strip("abc") = "abc"
* StringUtils.strip(" abc") = "abc"
* StringUtils.strip("abc ") = "abc"
* StringUtils.strip(" abc ") = "abc"
* StringUtils.strip(" ab c ") = "ab c"
*
*
* @param str the String to remove whitespace from, may be null
* @return the stripped String, null if null String input
*/
public static String strip(String str) {
return strip(str, null);
}
/**
* Strips whitespace from the start and end of a String returning
* null if the String is empty ("") after the strip.
*
* This is similar to {@link #trimToNull(String)} but removes whitespace.
* Whitespace is defined by {@link Character#isWhitespace(char)}.
*
*
* StringUtils.stripToNull(null) = null
* StringUtils.stripToNull("") = null
* StringUtils.stripToNull(" ") = null
* StringUtils.stripToNull("abc") = "abc"
* StringUtils.stripToNull(" abc") = "abc"
* StringUtils.stripToNull("abc ") = "abc"
* StringUtils.stripToNull(" abc ") = "abc"
* StringUtils.stripToNull(" ab c ") = "ab c"
*
*
* @param str the String to be stripped, may be null
* @return the stripped String,
* null if whitespace, empty or null String input
* @since 2.0
*/
public static String stripToNull(String str) {
if (str == null) {
return null;
}
str = strip(str, null);
return str.length() == 0 ? null : str;
}
/**
* Strips whitespace from the start and end of a String returning
* an empty String if null input.
*
* This is similar to {@link #trimToEmpty(String)} but removes whitespace.
* Whitespace is defined by {@link Character#isWhitespace(char)}.
*
*
* StringUtils.stripToEmpty(null) = ""
* StringUtils.stripToEmpty("") = ""
* StringUtils.stripToEmpty(" ") = ""
* StringUtils.stripToEmpty("abc") = "abc"
* StringUtils.stripToEmpty(" abc") = "abc"
* StringUtils.stripToEmpty("abc ") = "abc"
* StringUtils.stripToEmpty(" abc ") = "abc"
* StringUtils.stripToEmpty(" ab c ") = "ab c"
*
*
* @param str the String to be stripped, may be null
* @return the trimmed String, or an empty String if null input
* @since 2.0
*/
public static String stripToEmpty(String str) {
return str == null ? EMPTY : strip(str, null);
}
/**
* Strips any of a set of characters from the start and end of a String.
* This is similar to {@link String#trim()} but allows the characters
* to be stripped to be controlled.
*
* A null input String returns null.
* An empty string ("") input returns the empty string.
*
* If the stripChars String is null, whitespace is
* stripped as defined by {@link Character#isWhitespace(char)}.
* Alternatively use {@link #strip(String)}.
*
*
* StringUtils.strip(null, *) = null
* StringUtils.strip("", *) = ""
* StringUtils.strip("abc", null) = "abc"
* StringUtils.strip(" abc", null) = "abc"
* StringUtils.strip("abc ", null) = "abc"
* StringUtils.strip(" abc ", null) = "abc"
* StringUtils.strip(" abcyx", "xyz") = " abc"
*
*
* @param str the String to remove characters from, may be null
* @param stripChars the characters to remove, null treated as whitespace
* @return the stripped String, null if null String input
*/
public static String strip(String str, String stripChars) {
if (isEmpty(str)) {
return str;
}
str = stripStart(str, stripChars);
return stripEnd(str, stripChars);
}
/**
* Strips any of a set of characters from the start of a String.
*
* A null input String returns null.
* An empty string ("") input returns the empty string.
*
* If the stripChars String is null, whitespace is
* stripped as defined by {@link Character#isWhitespace(char)}.
*
*
* StringUtils.stripStart(null, *) = null
* StringUtils.stripStart("", *) = ""
* StringUtils.stripStart("abc", "") = "abc"
* StringUtils.stripStart("abc", null) = "abc"
* StringUtils.stripStart(" abc", null) = "abc"
* StringUtils.stripStart("abc ", null) = "abc "
* StringUtils.stripStart(" abc ", null) = "abc "
* StringUtils.stripStart("yxabc ", "xyz") = "abc "
*
*
* @param str the String to remove characters from, may be null
* @param stripChars the characters to remove, null treated as whitespace
* @return the stripped String, null if null String input
*/
public static String stripStart(String str, String stripChars) {
int strLen;
if (str == null || (strLen = str.length()) == 0) {
return str;
}
int start = 0;
if (stripChars == null) {
while ((start != strLen) && Character.isWhitespace(str.charAt(start))) {
start++;
}
} else if (stripChars.length() == 0) {
return str;
} else {
while ((start != strLen) && (stripChars.indexOf(str.charAt(start)) != INDEX_NOT_FOUND)) {
start++;
}
}
return str.substring(start);
}
/**
* Strips any of a set of characters from the end of a String.
*
* A null input String returns null.
* An empty string ("") input returns the empty string.
*
* If the stripChars String is null, whitespace is
* stripped as defined by {@link Character#isWhitespace(char)}.
*
*
* StringUtils.stripEnd(null, *) = null
* StringUtils.stripEnd("", *) = ""
* StringUtils.stripEnd("abc", "") = "abc"
* StringUtils.stripEnd("abc", null) = "abc"
* StringUtils.stripEnd(" abc", null) = " abc"
* StringUtils.stripEnd("abc ", null) = "abc"
* StringUtils.stripEnd(" abc ", null) = " abc"
* StringUtils.stripEnd(" abcyx", "xyz") = " abc"
* StringUtils.stripEnd("120.00", ".0") = "12"
*
*
* @param str the String to remove characters from, may be null
* @param stripChars the set of characters to remove, null treated as whitespace
* @return the stripped String, null if null String input
*/
public static String stripEnd(String str, String stripChars) {
int end;
if (str == null || (end = str.length()) == 0) {
return str;
}
if (stripChars == null) {
while ((end != 0) && Character.isWhitespace(str.charAt(end - 1))) {
end--;
}
} else if (stripChars.length() == 0) {
return str;
} else {
while ((end != 0) && (stripChars.indexOf(str.charAt(end - 1)) != INDEX_NOT_FOUND)) {
end--;
}
}
return str.substring(0, end);
}
// StripAll
//-----------------------------------------------------------------------
/**
* Strips whitespace from the start and end of every String in an array.
* Whitespace is defined by {@link Character#isWhitespace(char)}.
*
* A new array is returned each time, except for length zero.
* A null array will return null.
* An empty array will return itself.
* A null array entry will be ignored.
*
*
* StringUtils.stripAll(null) = null
* StringUtils.stripAll([]) = []
* StringUtils.stripAll(["abc", " abc"]) = ["abc", "abc"]
* StringUtils.stripAll(["abc ", null]) = ["abc", null]
*
*
* @param strs the array to remove whitespace from, may be null
* @return the stripped Strings, null if null array input
*/
public static String[] stripAll(String[] strs) {
return stripAll(strs, null);
}
/**
* Strips any of a set of characters from the start and end of every
* String in an array.
* Whitespace is defined by {@link Character#isWhitespace(char)}.
*
* A new array is returned each time, except for length zero.
* A null array will return null.
* An empty array will return itself.
* A null array entry will be ignored.
* A null stripChars will strip whitespace as defined by
* {@link Character#isWhitespace(char)}.
*
*
* StringUtils.stripAll(null, *) = null
* StringUtils.stripAll([], *) = []
* StringUtils.stripAll(["abc", " abc"], null) = ["abc", "abc"]
* StringUtils.stripAll(["abc ", null], null) = ["abc", null]
* StringUtils.stripAll(["abc ", null], "yz") = ["abc ", null]
* StringUtils.stripAll(["yabcz", null], "yz") = ["abc", null]
*
*
* @param strs the array to remove characters from, may be null
* @param stripChars the characters to remove, null treated as whitespace
* @return the stripped Strings, null if null array input
*/
public static String[] stripAll(String[] strs, String stripChars) {
int strsLen;
if (strs == null || (strsLen = strs.length) == 0) {
return strs;
}
String[] newArr = new String[strsLen];
for (int i = 0; i < strsLen; i++) {
newArr[i] = strip(strs[i], stripChars);
}
return newArr;
}
// Equals
//-----------------------------------------------------------------------
/**
* Compares two Strings, returning true if they are equal.
*
* nulls are handled without exceptions. Two null
* references are considered to be equal. The comparison is case sensitive.
*
*
* StringUtils.equals(null, null) = true
* StringUtils.equals(null, "abc") = false
* StringUtils.equals("abc", null) = false
* StringUtils.equals("abc", "abc") = true
* StringUtils.equals("abc", "ABC") = false
*
*
* @param str1 the first String, may be null
* @param str2 the second String, may be null
* @return true if the Strings are equal, case sensitive, or
* both null
* @see java.lang.String#equals(Object)
*/
public static boolean equals(String str1, String str2) {
return Objects.equals(str1, str2);
}
/**
* Compares two Strings, returning true if they are equal ignoring
* the case.
*
* nulls are handled without exceptions. Two null
* references are considered equal. Comparison is case insensitive.
*
*
* StringUtils.equalsIgnoreCase(null, null) = true
* StringUtils.equalsIgnoreCase(null, "abc") = false
* StringUtils.equalsIgnoreCase("abc", null) = false
* StringUtils.equalsIgnoreCase("abc", "abc") = true
* StringUtils.equalsIgnoreCase("abc", "ABC") = true
*
*
* @param str1 the first String, may be null
* @param str2 the second String, may be null
* @return true if the Strings are equal, case insensitive, or
* both null
* @see java.lang.String#equalsIgnoreCase(String)
*/
public static boolean equalsIgnoreCase(String str1, String str2) {
return str1 == null ? str2 == null : str1.equalsIgnoreCase(str2);
}
// IndexOf
//-----------------------------------------------------------------------
/**
* Finds the first index within a String, handling null.
* This method uses {@link String#indexOf(int)}.
*
* A null or empty ("") String will return INDEX_NOT_FOUND (-1).
*
*
* StringUtils.indexOf(null, *) = -1
* StringUtils.indexOf("", *) = -1
* StringUtils.indexOf("aabaabaa", 'a') = 0
* StringUtils.indexOf("aabaabaa", 'b') = 2
*
*
* @param str the String to check, may be null
* @param searchChar the character to find
* @return the first index of the search character,
* -1 if no match or null string input
* @since 2.0
*/
public static int indexOf(String str, char searchChar) {
if (isEmpty(str)) {
return INDEX_NOT_FOUND;
}
return str.indexOf(searchChar);
}
/**
* Finds the first index within a String from a start position,
* handling null.
* This method uses {@link String#indexOf(int, int)}.
*
* A null or empty ("") String will return (INDEX_NOT_FOUND) -1.
* A negative start position is treated as zero.
* A start position greater than the string length returns -1.
*
*
* StringUtils.indexOf(null, *, *) = -1
* StringUtils.indexOf("", *, *) = -1
* StringUtils.indexOf("aabaabaa", 'b', 0) = 2
* StringUtils.indexOf("aabaabaa", 'b', 3) = 5
* StringUtils.indexOf("aabaabaa", 'b', 9) = -1
* StringUtils.indexOf("aabaabaa", 'b', -1) = 2
*
*
* @param str the String to check, may be null
* @param searchChar the character to find
* @param startPos the start position, negative treated as zero
* @return the first index of the search character,
* -1 if no match or null string input
* @since 2.0
*/
public static int indexOf(String str, char searchChar, int startPos) {
if (isEmpty(str)) {
return INDEX_NOT_FOUND;
}
return str.indexOf(searchChar, startPos);
}
/**
* Finds the first index within a String, handling null.
* This method uses {@link String#indexOf(String)}.
*
* A null String will return -1.
*
*
* StringUtils.indexOf(null, *) = -1
* StringUtils.indexOf(*, null) = -1
* StringUtils.indexOf("", "") = 0
* StringUtils.indexOf("", *) = -1 (except when * = "")
* StringUtils.indexOf("aabaabaa", "a") = 0
* StringUtils.indexOf("aabaabaa", "b") = 2
* StringUtils.indexOf("aabaabaa", "ab") = 1
* StringUtils.indexOf("aabaabaa", "") = 0
*
*
* @param str the String to check, may be null
* @param searchStr the String to find, may be null
* @return the first index of the search String,
* -1 if no match or null string input
* @since 2.0
*/
public static int indexOf(String str, String searchStr) {
if (str == null || searchStr == null) {
return INDEX_NOT_FOUND;
}
return str.indexOf(searchStr);
}
/**
* Finds the n-th index within a String, handling null.
* This method uses {@link String#indexOf(String)}.
*
* A null String will return -1.
*
*
* StringUtils.ordinalIndexOf(null, *, *) = -1
* StringUtils.ordinalIndexOf(*, null, *) = -1
* StringUtils.ordinalIndexOf("", "", *) = 0
* StringUtils.ordinalIndexOf("aabaabaa", "a", 1) = 0
* StringUtils.ordinalIndexOf("aabaabaa", "a", 2) = 1
* StringUtils.ordinalIndexOf("aabaabaa", "b", 1) = 2
* StringUtils.ordinalIndexOf("aabaabaa", "b", 2) = 5
* StringUtils.ordinalIndexOf("aabaabaa", "ab", 1) = 1
* StringUtils.ordinalIndexOf("aabaabaa", "ab", 2) = 4
* StringUtils.ordinalIndexOf("aabaabaa", "", 1) = 0
* StringUtils.ordinalIndexOf("aabaabaa", "", 2) = 0
*
*
* Note that 'head(String str, int n)' may be implemented as:
*
*
* str.substring(0, lastOrdinalIndexOf(str, "\n", n))
*
*
* @param str the String to check, may be null
* @param searchStr the String to find, may be null
* @param ordinal the n-th searchStr to find
* @return the n-th index of the search String,
* -1 (INDEX_NOT_FOUND) if no match or null string input
* @since 2.1
*/
public static int ordinalIndexOf(String str, String searchStr, int ordinal) {
return ordinalIndexOf(str, searchStr, ordinal, false);
}
/**
* Finds the n-th index within a String, handling null.
* This method uses {@link String#indexOf(String)}.
*
* A null String will return -1.
*
* @param str the String to check, may be null
* @param searchStr the String to find, may be null
* @param ordinal the n-th searchStr to find
* @param lastIndex true if lastOrdinalIndexOf() otherwise false if ordinalIndexOf()
* @return the n-th index of the search String,
* -1 (INDEX_NOT_FOUND) if no match or null string input
*/
// Shared code between ordinalIndexOf(String,String,int) and lastOrdinalIndexOf(String,String,int)
private static int ordinalIndexOf(String str, String searchStr, int ordinal, boolean lastIndex) {
if (str == null || searchStr == null || ordinal <= 0) {
return INDEX_NOT_FOUND;
}
if (searchStr.length() == 0) {
return lastIndex ? str.length() : 0;
}
int found = 0;
int index = lastIndex ? str.length() : INDEX_NOT_FOUND;
do {
if (lastIndex) {
index = str.lastIndexOf(searchStr, index - 1);
} else {
index = str.indexOf(searchStr, index + 1);
}
if (index < 0) {
return index;
}
found++;
} while (found < ordinal);
return index;
}
/**
* Finds the first index within a String, handling null.
* This method uses {@link String#indexOf(String, int)}.
*
* A null String will return -1.
* A negative start position is treated as zero.
* An empty ("") search String always matches.
* A start position greater than the string length only matches
* an empty search String.
*
*
* StringUtils.indexOf(null, *, *) = -1
* StringUtils.indexOf(*, null, *) = -1
* StringUtils.indexOf("", "", 0) = 0
* StringUtils.indexOf("", *, 0) = -1 (except when * = "")
* StringUtils.indexOf("aabaabaa", "a", 0) = 0
* StringUtils.indexOf("aabaabaa", "b", 0) = 2
* StringUtils.indexOf("aabaabaa", "ab", 0) = 1
* StringUtils.indexOf("aabaabaa", "b", 3) = 5
* StringUtils.indexOf("aabaabaa", "b", 9) = -1
* StringUtils.indexOf("aabaabaa", "b", -1) = 2
* StringUtils.indexOf("aabaabaa", "", 2) = 2
* StringUtils.indexOf("abc", "", 9) = 3
*
*
* @param str the String to check, may be null
* @param searchStr the String to find, may be null
* @param startPos the start position, negative treated as zero
* @return the first index of the search String,
* -1 if no match or null string input
* @since 2.0
*/
public static int indexOf(String str, String searchStr, int startPos) {
if (str == null || searchStr == null) {
return INDEX_NOT_FOUND;
}
// JDK1.2/JDK1.3 have a bug, when startPos > str.length for "", hence
if (searchStr.length() == 0 && startPos >= str.length()) {
return str.length();
}
return str.indexOf(searchStr, startPos);
}
/**
* Case in-sensitive find of the first index within a String.
*
* A null String will return -1.
* A negative start position is treated as zero.
* An empty ("") search String always matches.
* A start position greater than the string length only matches
* an empty search String.
*
*
* StringUtils.indexOfIgnoreCase(null, *) = -1
* StringUtils.indexOfIgnoreCase(*, null) = -1
* StringUtils.indexOfIgnoreCase("", "") = 0
* StringUtils.indexOfIgnoreCase("aabaabaa", "a") = 0
* StringUtils.indexOfIgnoreCase("aabaabaa", "b") = 2
* StringUtils.indexOfIgnoreCase("aabaabaa", "ab") = 1
*
*
* @param str the String to check, may be null
* @param searchStr the String to find, may be null
* @return the first index of the search String,
* -1 if no match or null string input
* @since 2.5
*/
public static int indexOfIgnoreCase(String str, String searchStr) {
return indexOfIgnoreCase(str, searchStr, 0);
}
/**
* Case in-sensitive find of the first index within a String
* from the specified position.
*
* A null String will return -1.
* A negative start position is treated as zero.
* An empty ("") search String always matches.
* A start position greater than the string length only matches
* an empty search String.
*
*
* StringUtils.indexOfIgnoreCase(null, *, *) = -1
* StringUtils.indexOfIgnoreCase(*, null, *) = -1
* StringUtils.indexOfIgnoreCase("", "", 0) = 0
* StringUtils.indexOfIgnoreCase("aabaabaa", "A", 0) = 0
* StringUtils.indexOfIgnoreCase("aabaabaa", "B", 0) = 2
* StringUtils.indexOfIgnoreCase("aabaabaa", "AB", 0) = 1
* StringUtils.indexOfIgnoreCase("aabaabaa", "B", 3) = 5
* StringUtils.indexOfIgnoreCase("aabaabaa", "B", 9) = -1
* StringUtils.indexOfIgnoreCase("aabaabaa", "B", -1) = 2
* StringUtils.indexOfIgnoreCase("aabaabaa", "", 2) = 2
* StringUtils.indexOfIgnoreCase("abc", "", 9) = 3
*
*
* @param str the String to check, may be null
* @param searchStr the String to find, may be null
* @param startPos the start position, negative treated as zero
* @return the first index of the search String,
* -1 if no match or null string input
* @since 2.5
*/
public static int indexOfIgnoreCase(String str, String searchStr, int startPos) {
if (str == null || searchStr == null) {
return INDEX_NOT_FOUND;
}
if (startPos < 0) {
startPos = 0;
}
int endLimit = (str.length() - searchStr.length()) + 1;
if (startPos > endLimit) {
return INDEX_NOT_FOUND;
}
if (searchStr.length() == 0) {
return startPos;
}
for (int i = startPos; i < endLimit; i++) {
if (str.regionMatches(true, i, searchStr, 0, searchStr.length())) {
return i;
}
}
return INDEX_NOT_FOUND;
}
// LastIndexOf
//-----------------------------------------------------------------------
/**
* Finds the last index within a String, handling null.
* This method uses {@link String#lastIndexOf(int)}.
*
* A null or empty ("") String will return -1.
*
*
* StringUtils.lastIndexOf(null, *) = -1
* StringUtils.lastIndexOf("", *) = -1
* StringUtils.lastIndexOf("aabaabaa", 'a') = 7
* StringUtils.lastIndexOf("aabaabaa", 'b') = 5
*
*
* @param str the String to check, may be null
* @param searchChar the character to find
* @return the last index of the search character,
* -1 if no match or null string input
* @since 2.0
*/
public static int lastIndexOf(String str, char searchChar) {
if (isEmpty(str)) {
return INDEX_NOT_FOUND;
}
return str.lastIndexOf(searchChar);
}
/**
* Finds the last index within a String from a start position,
* handling null.
* This method uses {@link String#lastIndexOf(int, int)}.
*
* A null or empty ("") String will return -1.
* A negative start position returns -1.
* A start position greater than the string length searches the whole string.
*
*
* StringUtils.lastIndexOf(null, *, *) = -1
* StringUtils.lastIndexOf("", *, *) = -1
* StringUtils.lastIndexOf("aabaabaa", 'b', 8) = 5
* StringUtils.lastIndexOf("aabaabaa", 'b', 4) = 2
* StringUtils.lastIndexOf("aabaabaa", 'b', 0) = -1
* StringUtils.lastIndexOf("aabaabaa", 'b', 9) = 5
* StringUtils.lastIndexOf("aabaabaa", 'b', -1) = -1
* StringUtils.lastIndexOf("aabaabaa", 'a', 0) = 0
*
*
* @param str the String to check, may be null
* @param searchChar the character to find
* @param startPos the start position
* @return the last index of the search character,
* -1 if no match or null string input
* @since 2.0
*/
public static int lastIndexOf(String str, char searchChar, int startPos) {
if (isEmpty(str)) {
return INDEX_NOT_FOUND;
}
return str.lastIndexOf(searchChar, startPos);
}
/**
* Finds the last index within a String, handling null.
* This method uses {@link String#lastIndexOf(String)}.
*
* A null String will return -1.
*
*
* StringUtils.lastIndexOf(null, *) = -1
* StringUtils.lastIndexOf(*, null) = -1
* StringUtils.lastIndexOf("", "") = 0
* StringUtils.lastIndexOf("aabaabaa", "a") = 7
* StringUtils.lastIndexOf("aabaabaa", "b") = 5
* StringUtils.lastIndexOf("aabaabaa", "ab") = 4
* StringUtils.lastIndexOf("aabaabaa", "") = 8
*
*
* @param str the String to check, may be null
* @param searchStr the String to find, may be null
* @return the last index of the search String,
* -1 if no match or null string input
* @since 2.0
*/
public static int lastIndexOf(String str, String searchStr) {
if (str == null || searchStr == null) {
return INDEX_NOT_FOUND;
}
return str.lastIndexOf(searchStr);
}
/**
* Finds the n-th last index within a String, handling null.
* This method uses {@link String#lastIndexOf(String)}.
*
* A null String will return -1.
*
*
* StringUtils.lastOrdinalIndexOf(null, *, *) = -1
* StringUtils.lastOrdinalIndexOf(*, null, *) = -1
* StringUtils.lastOrdinalIndexOf("", "", *) = 0
* StringUtils.lastOrdinalIndexOf("aabaabaa", "a", 1) = 7
* StringUtils.lastOrdinalIndexOf("aabaabaa", "a", 2) = 6
* StringUtils.lastOrdinalIndexOf("aabaabaa", "b", 1) = 5
* StringUtils.lastOrdinalIndexOf("aabaabaa", "b", 2) = 2
* StringUtils.lastOrdinalIndexOf("aabaabaa", "ab", 1) = 4
* StringUtils.lastOrdinalIndexOf("aabaabaa", "ab", 2) = 1
* StringUtils.lastOrdinalIndexOf("aabaabaa", "", 1) = 8
* StringUtils.lastOrdinalIndexOf("aabaabaa", "", 2) = 8
*
*
* Note that 'tail(String str, int n)' may be implemented as:
*
*
* str.substring(lastOrdinalIndexOf(str, "\n", n) + 1)
*
*
* @param str the String to check, may be null
* @param searchStr the String to find, may be null
* @param ordinal the n-th last searchStr to find
* @return the n-th last index of the search String,
* -1 (INDEX_NOT_FOUND) if no match or null string input
* @since 2.5
*/
public static int lastOrdinalIndexOf(String str, String searchStr, int ordinal) {
return ordinalIndexOf(str, searchStr, ordinal, true);
}
/**
* Finds the first index within a String, handling null.
* This method uses {@link String#lastIndexOf(String, int)}.
*
* A null String will return -1.
* A negative start position returns -1.
* An empty ("") search String always matches unless the start position is negative.
* A start position greater than the string length searches the whole string.
*
*
* StringUtils.lastIndexOf(null, *, *) = -1
* StringUtils.lastIndexOf(*, null, *) = -1
* StringUtils.lastIndexOf("aabaabaa", "a", 8) = 7
* StringUtils.lastIndexOf("aabaabaa", "b", 8) = 5
* StringUtils.lastIndexOf("aabaabaa", "ab", 8) = 4
* StringUtils.lastIndexOf("aabaabaa", "b", 9) = 5
* StringUtils.lastIndexOf("aabaabaa", "b", -1) = -1
* StringUtils.lastIndexOf("aabaabaa", "a", 0) = 0
* StringUtils.lastIndexOf("aabaabaa", "b", 0) = -1
*
*
* @param str the String to check, may be null
* @param searchStr the String to find, may be null
* @param startPos the start position, negative treated as zero
* @return the first index of the search String,
* -1 if no match or null string input
* @since 2.0
*/
public static int lastIndexOf(String str, String searchStr, int startPos) {
if (str == null || searchStr == null) {
return INDEX_NOT_FOUND;
}
return str.lastIndexOf(searchStr, startPos);
}
/**
* Case in-sensitive find of the last index within a String.
*
* A null String will return -1.
* A negative start position returns -1.
* An empty ("") search String always matches unless the start position is negative.
* A start position greater than the string length searches the whole string.
*
*
* StringUtils.lastIndexOfIgnoreCase(null, *) = -1
* StringUtils.lastIndexOfIgnoreCase(*, null) = -1
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "A") = 7
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B") = 5
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "AB") = 4
*
*
* @param str the String to check, may be null
* @param searchStr the String to find, may be null
* @return the first index of the search String,
* -1 if no match or null string input
* @since 2.5
*/
public static int lastIndexOfIgnoreCase(String str, String searchStr) {
if (str == null || searchStr == null) {
return INDEX_NOT_FOUND;
}
return lastIndexOfIgnoreCase(str, searchStr, str.length());
}
/**
* Case in-sensitive find of the last index within a String
* from the specified position.
*
* A null String will return -1.
* A negative start position returns -1.
* An empty ("") search String always matches unless the start position is negative.
* A start position greater than the string length searches the whole string.
*
*
* StringUtils.lastIndexOfIgnoreCase(null, *, *) = -1
* StringUtils.lastIndexOfIgnoreCase(*, null, *) = -1
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "A", 8) = 7
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", 8) = 5
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "AB", 8) = 4
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", 9) = 5
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", -1) = -1
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "A", 0) = 0
* StringUtils.lastIndexOfIgnoreCase("aabaabaa", "B", 0) = -1
*
*
* @param str the String to check, may be null
* @param searchStr the String to find, may be null
* @param startPos the start position
* @return the first index of the search String,
* -1 if no match or null string input
* @since 2.5
*/
public static int lastIndexOfIgnoreCase(String str, String searchStr, int startPos) {
if (str == null || searchStr == null) {
return INDEX_NOT_FOUND;
}
if (startPos > (str.length() - searchStr.length())) {
startPos = str.length() - searchStr.length();
}
if (startPos < 0) {
return INDEX_NOT_FOUND;
}
if (searchStr.length() == 0) {
return startPos;
}
for (int i = startPos; i >= 0; i--) {
if (str.regionMatches(true, i, searchStr, 0, searchStr.length())) {
return i;
}
}
return INDEX_NOT_FOUND;
}
// Contains
//-----------------------------------------------------------------------
/**
* Checks if String contains a search character, handling null.
* This method uses {@link String#indexOf(int)}.
*
* A null or empty ("") String will return false.
*
*
* StringUtils.contains(null, *) = false
* StringUtils.contains("", *) = false
* StringUtils.contains("abc", 'a') = true
* StringUtils.contains("abc", 'z') = false
*
*
* @param str the String to check, may be null
* @param searchChar the character to find
* @return true if the String contains the search character,
* false if not or null string input
* @since 2.0
*/
public static boolean contains(String str, char searchChar) {
if (isEmpty(str)) {
return false;
}
return str.indexOf(searchChar) >= 0;
}
/**
* Checks if String contains a search String, handling null.
* This method uses {@link String#indexOf(String)}.
*
* A null String will return false.
*
*
* StringUtils.contains(null, *) = false
* StringUtils.contains(*, null) = false
* StringUtils.contains("", "") = true
* StringUtils.contains("abc", "") = true
* StringUtils.contains("abc", "a") = true
* StringUtils.contains("abc", "z") = false
*
*
* @param str the String to check, may be null
* @param searchStr the String to find, may be null
* @return true if the String contains the search String,
* false if not or null string input
* @since 2.0
*/
public static boolean contains(String str, String searchStr) {
if (str == null || searchStr == null) {
return false;
}
return str.indexOf(searchStr) >= 0;
}
/**
* Checks if String contains a search String irrespective of case,
* handling null. Case-insensitivity is defined as by
* {@link String#equalsIgnoreCase(String)}.
*
*
A null String will return false.
*
*
* StringUtils.contains(null, *) = false
* StringUtils.contains(*, null) = false
* StringUtils.contains("", "") = true
* StringUtils.contains("abc", "") = true
* StringUtils.contains("abc", "a") = true
* StringUtils.contains("abc", "z") = false
* StringUtils.contains("abc", "A") = true
* StringUtils.contains("abc", "Z") = false
*
*
* @param str the String to check, may be null
* @param searchStr the String to find, may be null
* @return true if the String contains the search String irrespective of
* case or false if not or null string input
*/
public static boolean containsIgnoreCase(String str, String searchStr) {
if (str == null || searchStr == null) {
return false;
}
int len = searchStr.length();
int max = str.length() - len;
for (int i = 0; i <= max; i++) {
if (str.regionMatches(true, i, searchStr, 0, len)) {
return true;
}
}
return false;
}
// IndexOfAny strings
//-----------------------------------------------------------------------
/**
* Find the first index of any of a set of potential substrings.
*
* A null String will return -1.
* A null or zero length search array will return -1.
* A null search array entry will be ignored, but a search
* array containing "" will return 0 if str is not
* null. This method uses {@link String#indexOf(String)}.
*
*
* StringUtils.indexOfAny(null, *) = -1
* StringUtils.indexOfAny(*, null) = -1
* StringUtils.indexOfAny(*, []) = -1
* StringUtils.indexOfAny("zzabyycdxx", ["ab","cd"]) = 2
* StringUtils.indexOfAny("zzabyycdxx", ["cd","ab"]) = 2
* StringUtils.indexOfAny("zzabyycdxx", ["mn","op"]) = -1
* StringUtils.indexOfAny("zzabyycdxx", ["zab","aby"]) = 1
* StringUtils.indexOfAny("zzabyycdxx", [""]) = 0
* StringUtils.indexOfAny("", [""]) = 0
* StringUtils.indexOfAny("", ["a"]) = -1
*
*
* @param str the String to check, may be null
* @param searchStrs the Strings to search for, may be null
* @return the first index of any of the searchStrs in str, -1 if no match
*/
public static int indexOfAny(String str, String[] searchStrs) {
if ((str == null) || (searchStrs == null)) {
return INDEX_NOT_FOUND;
}
int sz = searchStrs.length;
// String's can't have a MAX_VALUEth index.
int ret = Integer.MAX_VALUE;
int tmp = 0;
for (String search : searchStrs) {
if (search == null) {
continue;
}
tmp = str.indexOf(search);
if (tmp == INDEX_NOT_FOUND) {
continue;
}
if (tmp < ret) {
ret = tmp;
}
}
return (ret == Integer.MAX_VALUE) ? INDEX_NOT_FOUND : ret;
}
/**
* Find the latest index of any of a set of potential substrings.
*
* A null String will return -1.
* A null search array will return -1.
* A null or zero length search array entry will be ignored,
* but a search array containing "" will return the length of str
* if str is not null. This method uses {@link String#indexOf(String)}
*
*
* StringUtils.lastIndexOfAny(null, *) = -1
* StringUtils.lastIndexOfAny(*, null) = -1
* StringUtils.lastIndexOfAny(*, []) = -1
* StringUtils.lastIndexOfAny(*, [null]) = -1
* StringUtils.lastIndexOfAny("zzabyycdxx", ["ab","cd"]) = 6
* StringUtils.lastIndexOfAny("zzabyycdxx", ["cd","ab"]) = 6
* StringUtils.lastIndexOfAny("zzabyycdxx", ["mn","op"]) = -1
* StringUtils.lastIndexOfAny("zzabyycdxx", ["mn","op"]) = -1
* StringUtils.lastIndexOfAny("zzabyycdxx", ["mn",""]) = 10
*
*
* @param str the String to check, may be null
* @param searchStrs the Strings to search for, may be null
* @return the last index of any of the Strings, -1 if no match
*/
public static int lastIndexOfAny(String str, String[] searchStrs) {
if ((str == null) || (searchStrs == null)) {
return INDEX_NOT_FOUND;
}
int sz = searchStrs.length;
int ret = INDEX_NOT_FOUND;
int tmp = 0;
for (String search : searchStrs) {
if (search == null) {
continue;
}
tmp = str.lastIndexOf(search);
if (tmp > ret) {
ret = tmp;
}
}
return ret;
}
// Substring
//-----------------------------------------------------------------------
/**
* Gets a substring from the specified String avoiding exceptions.
*
* A negative start position can be used to start n
* characters from the end of the String.
*
* A null String will return null.
* An empty ("") String will return "".
*
*
* StringUtils.substring(null, *) = null
* StringUtils.substring("", *) = ""
* StringUtils.substring("abc", 0) = "abc"
* StringUtils.substring("abc", 2) = "c"
* StringUtils.substring("abc", 4) = ""
* StringUtils.substring("abc", -2) = "bc"
* StringUtils.substring("abc", -4) = "abc"
*
*
* @param str the String to get the substring from, may be null
* @param start the position to start from, negative means
* count back from the end of the String by this many characters
* @return substring from start position, null if null String input
*/
public static String substring(String str, int start) {
if (str == null) {
return null;
}
// handle negatives, which means last n characters
if (start < 0) {
start = str.length() + start; // remember start is negative
}
if (start < 0) {
start = 0;
}
if (start > str.length()) {
return EMPTY;
}
return str.substring(start);
}
/**
* Gets a substring from the specified String avoiding exceptions.
*
* A negative start position can be used to start/end n
* characters from the end of the String.
*
* The returned substring starts with the character in the start
* position and ends before the end position. All position counting is
* zero-based -- i.e., to start at the beginning of the string use
* start = 0. Negative start and end positions can be used to
* specify offsets relative to the end of the String.
*
* If start is not strictly to the left of end, ""
* is returned.
*
*
* StringUtils.substring(null, *, *) = null
* StringUtils.substring("", * , *) = "";
* StringUtils.substring("abc", 0, 2) = "ab"
* StringUtils.substring("abc", 2, 0) = ""
* StringUtils.substring("abc", 2, 4) = "c"
* StringUtils.substring("abc", 4, 6) = ""
* StringUtils.substring("abc", 2, 2) = ""
* StringUtils.substring("abc", -2, -1) = "b"
* StringUtils.substring("abc", -4, 2) = "ab"
*
*
* @param str the String to get the substring from, may be null
* @param start the position to start from, negative means
* count back from the end of the String by this many characters
* @param end the position to end at (exclusive), negative means
* count back from the end of the String by this many characters
* @return substring from start position to end positon,
* null if null String input
*/
public static String substring(String str, int start, int end) {
if (str == null) {
return null;
}
// handle negatives
if (end < 0) {
end = str.length() + end; // remember end is negative
}
if (start < 0) {
start = str.length() + start; // remember start is negative
}
// check length next
if (end > str.length()) {
end = str.length();
}
// if start is greater than end, return ""
if (start > end) {
return EMPTY;
}
if (start < 0) {
start = 0;
}
if (end < 0) {
end = 0;
}
return str.substring(start, end);
}
// Left/Right/Mid
//-----------------------------------------------------------------------
/**
* Gets the leftmost len characters of a String.
*
* If len characters are not available, or the
* String is null, the String will be returned without
* an exception. An empty String is returned if len is negative.
*
*
* StringUtils.left(null, *) = null
* StringUtils.left(*, -ve) = ""
* StringUtils.left("", *) = ""
* StringUtils.left("abc", 0) = ""
* StringUtils.left("abc", 2) = "ab"
* StringUtils.left("abc", 4) = "abc"
*
*
* @param str the String to get the leftmost characters from, may be null
* @param len the length of the required String
* @return the leftmost characters, null if null String input
*/
public static String left(String str, int len) {
if (str == null) {
return null;
}
if (len < 0) {
return EMPTY;
}
if (str.length() <= len) {
return str;
}
return str.substring(0, len);
}
/**
* Gets the rightmost len characters of a String.
*
* If len characters are not available, or the String
* is null, the String will be returned without an
* an exception. An empty String is returned if len is negative.
*
*
* StringUtils.right(null, *) = null
* StringUtils.right(*, -ve) = ""
* StringUtils.right("", *) = ""
* StringUtils.right("abc", 0) = ""
* StringUtils.right("abc", 2) = "bc"
* StringUtils.right("abc", 4) = "abc"
*
*
* @param str the String to get the rightmost characters from, may be null
* @param len the length of the required String
* @return the rightmost characters, null if null String input
*/
public static String right(String str, int len) {
if (str == null) {
return null;
}
if (len < 0) {
return EMPTY;
}
if (str.length() <= len) {
return str;
}
return str.substring(str.length() - len);
}
/**
* Gets len characters from the middle of a String.
*
* If len characters are not available, the remainder
* of the String will be returned without an exception. If the
* String is null, null will be returned.
* An empty String is returned if len is negative or exceeds the
* length of str.
*
*
* StringUtils.mid(null, *, *) = null
* StringUtils.mid(*, *, -ve) = ""
* StringUtils.mid("", 0, *) = ""
* StringUtils.mid("abc", 0, 2) = "ab"
* StringUtils.mid("abc", 0, 4) = "abc"
* StringUtils.mid("abc", 2, 4) = "c"
* StringUtils.mid("abc", 4, 2) = ""
* StringUtils.mid("abc", -2, 2) = "ab"
*
*
* @param str the String to get the characters from, may be null
* @param pos the position to start from, negative treated as zero
* @param len the length of the required String
* @return the middle characters, null if null String input
*/
public static String mid(String str, int pos, int len) {
if (str == null) {
return null;
}
if (len < 0 || pos > str.length()) {
return EMPTY;
}
if (pos < 0) {
pos = 0;
}
if (str.length() <= (pos + len)) {
return str.substring(pos);
}
return str.substring(pos, pos + len);
}
// SubStringAfter/SubStringBefore
//-----------------------------------------------------------------------
/**
* Gets the substring before the first occurrence of a separator.
* The separator is not returned.
*
* A null string input will return null.
* An empty ("") string input will return the empty string.
* A null separator will return the input string.
*
* If nothing is found, the string input is returned.
*
*
* StringUtils.substringBefore(null, *) = null
* StringUtils.substringBefore("", *) = ""
* StringUtils.substringBefore("abc", "a") = ""
* StringUtils.substringBefore("abcba", "b") = "a"
* StringUtils.substringBefore("abc", "c") = "ab"
* StringUtils.substringBefore("abc", "d") = "abc"
* StringUtils.substringBefore("abc", "") = ""
* StringUtils.substringBefore("abc", null) = "abc"
*
*
* @param str the String to get a substring from, may be null
* @param separator the String to search for, may be null
* @return the substring before the first occurrence of the separator,
* null if null String input
* @since 2.0
*/
public static String substringBefore(String str, String separator) {
if (isEmpty(str) || separator == null) {
return str;
}
if (separator.length() == 0) {
return EMPTY;
}
int pos = str.indexOf(separator);
if (pos == INDEX_NOT_FOUND) {
return str;
}
return str.substring(0, pos);
}
/**
* Gets the substring after the first occurrence of a separator.
* The separator is not returned.
*
* A null string input will return null.
* An empty ("") string input will return the empty string.
* A null separator will return the empty string if the
* input string is not null.
*
* If nothing is found, the empty string is returned.
*
*
* StringUtils.substringAfter(null, *) = null
* StringUtils.substringAfter("", *) = ""
* StringUtils.substringAfter(*, null) = ""
* StringUtils.substringAfter("abc", "a") = "bc"
* StringUtils.substringAfter("abcba", "b") = "cba"
* StringUtils.substringAfter("abc", "c") = ""
* StringUtils.substringAfter("abc", "d") = ""
* StringUtils.substringAfter("abc", "") = "abc"
*
*
* @param str the String to get a substring from, may be null
* @param separator the String to search for, may be null
* @return the substring after the first occurrence of the separator,
* null if null String input
* @since 2.0
*/
public static String substringAfter(String str, String separator) {
if (isEmpty(str)) {
return str;
}
if (separator == null) {
return EMPTY;
}
int pos = str.indexOf(separator);
if (pos == INDEX_NOT_FOUND) {
return EMPTY;
}
return str.substring(pos + separator.length());
}
/**
* Gets the substring before the last occurrence of a separator.
* The separator is not returned.
*
* A null string input will return null.
* An empty ("") string input will return the empty string.
* An empty or null separator will return the input string.
*
* If nothing is found, the string input is returned.
*
*
* StringUtils.substringBeforeLast(null, *) = null
* StringUtils.substringBeforeLast("", *) = ""
* StringUtils.substringBeforeLast("abcba", "b") = "abc"
* StringUtils.substringBeforeLast("abc", "c") = "ab"
* StringUtils.substringBeforeLast("a", "a") = ""
* StringUtils.substringBeforeLast("a", "z") = "a"
* StringUtils.substringBeforeLast("a", null) = "a"
* StringUtils.substringBeforeLast("a", "") = "a"
*
*
* @param str the String to get a substring from, may be null
* @param separator the String to search for, may be null
* @return the substring before the last occurrence of the separator,
* null if null String input
* @since 2.0
*/
public static String substringBeforeLast(String str, String separator) {
if (isEmpty(str) || isEmpty(separator)) {
return str;
}
int pos = str.lastIndexOf(separator);
if (pos == INDEX_NOT_FOUND) {
return str;
}
return str.substring(0, pos);
}
/**
* Gets the substring after the last occurrence of a separator.
* The separator is not returned.
*
* A null string input will return null.
* An empty ("") string input will return the empty string.
* An empty or null separator will return the empty string if
* the input string is not null.
*
* If nothing is found, the empty string is returned.
*
*
* StringUtils.substringAfterLast(null, *) = null
* StringUtils.substringAfterLast("", *) = ""
* StringUtils.substringAfterLast(*, "") = ""
* StringUtils.substringAfterLast(*, null) = ""
* StringUtils.substringAfterLast("abc", "a") = "bc"
* StringUtils.substringAfterLast("abcba", "b") = "a"
* StringUtils.substringAfterLast("abc", "c") = ""
* StringUtils.substringAfterLast("a", "a") = ""
* StringUtils.substringAfterLast("a", "z") = ""
*
*
* @param str the String to get a substring from, may be null
* @param separator the String to search for, may be null
* @return the substring after the last occurrence of the separator,
* null if null String input
* @since 2.0
*/
public static String substringAfterLast(String str, String separator) {
if (isEmpty(str)) {
return str;
}
if (isEmpty(separator)) {
return EMPTY;
}
int pos = str.lastIndexOf(separator);
if (pos == INDEX_NOT_FOUND || pos == (str.length() - separator.length())) {
return EMPTY;
}
return str.substring(pos + separator.length());
}
// Substring between
//-----------------------------------------------------------------------
/**
* Gets the String that is nested in between two instances of the
* same String.
*
* A null input String returns null.
* A null tag returns null.
*
*
* StringUtils.substringBetween(null, *) = null
* StringUtils.substringBetween("", "") = ""
* StringUtils.substringBetween("", "tag") = null
* StringUtils.substringBetween("tagabctag", null) = null
* StringUtils.substringBetween("tagabctag", "") = ""
* StringUtils.substringBetween("tagabctag", "tag") = "abc"
*
*
* @param str the String containing the substring, may be null
* @param tag the String before and after the substring, may be null
* @return the substring, null if no match
* @since 2.0
*/
public static String substringBetween(String str, String tag) {
return substringBetween(str, tag, tag);
}
/**
* Gets the String that is nested in between two Strings.
* Only the first match is returned.
*
* A null input String returns null.
* A null open/close returns null (no match).
* An empty ("") open and close returns an empty string.
*
*
* StringUtils.substringBetween("wx[b]yz", "[", "]") = "b"
* StringUtils.substringBetween(null, *, *) = null
* StringUtils.substringBetween(*, null, *) = null
* StringUtils.substringBetween(*, *, null) = null
* StringUtils.substringBetween("", "", "") = ""
* StringUtils.substringBetween("", "", "]") = null
* StringUtils.substringBetween("", "[", "]") = null
* StringUtils.substringBetween("yabcz", "", "") = ""
* StringUtils.substringBetween("yabcz", "y", "z") = "abc"
* StringUtils.substringBetween("yabczyabcz", "y", "z") = "abc"
*
*
* @param str the String containing the substring, may be null
* @param open the String before the substring, may be null
* @param close the String after the substring, may be null
* @return the substring, null if no match
* @since 2.0
*/
public static String substringBetween(String str, String open, String close) {
if (str == null || open == null || close == null) {
return null;
}
int start = str.indexOf(open);
if (start != INDEX_NOT_FOUND) {
int end = str.indexOf(close, start + open.length());
if (end != INDEX_NOT_FOUND) {
return str.substring(start + open.length(), end);
}
}
return null;
}
}