java.lang.Object
- org.codehaus.plexus.util.StringUtils

```
public class StringUtils
extends Object
```
Common String manipulation routines.

Originally from Turbine and the GenerationJavaCore library.

Since:

1.0

Author:

Jon S. Stevens, Daniel Rall, Greg Coladonato, Henri Yandell, Ed Korthof, Rand McNeely, Stephen Colebourne, Fredrik Westermarck, Holger Krauth, Alexander Day Chaffee, Vincent Siveton

Constructor Summary

Constructors
Constructor Description

StringUtils()
StringUtils instances should NOT be constructed in standard programming.

Method Summary

All Methods Static Methods Concrete Methods Deprecated Methods
Modifier and Type	Method	Description
`static String`	`abbreviate(String s, int maxWidth)`
`static String`	`abbreviate(String s, int offset, int maxWidth)`
`static String`	`addAndDeHump(String view)`
`static String`	`capitalise(String str)`	Capitalise a String.
`static String`	`capitaliseAllWords(String str)`	Capitalise all the words in a String.
`static String`	`capitalizeFirstLetter(String data)`
`static String`	`center(String str, int size)`	Center a String in a larger String of size `n`.
`static String`	`center(String str, int size, String delim)`	Center a String in a larger String of size `n`.
`static String`	`chomp(String str)`	Remove the last newline, and everything after it from a String.
`static String`	`chomp(String str, String sep)`	Remove the last value of a supplied String, and everything after it from a String.
`static String`	`chompLast(String str)`	Remove a newline if and only if it is at the end of the supplied String.
`static String`	`chompLast(String str, String sep)`	Remove a value if and only if the String ends with that value.
`static String`	`chop(String str)`	Remove the last character from a String.
`static String`	`chopNewline(String str)`	Remove `\n` from end of a String if it's there.
`static String`	`clean(String str)`	Removes control characters, including whitespace, from both ends of this String, handling `null` by returning an empty String.
`static String`	`concatenate(Object[] array)`	Concatenates elements of an array into a single String.
`static boolean`	`contains(String str, char searchChar)`	Checks if String contains a search character, handling `null`.
`static boolean`	`contains(String str, String searchStr)`	Checks if String contains a search String, handling `null`.
`static int`	`countMatches(String str, String sub)`	How many times is the substring in the larger String.
`static String`	`defaultString(Object obj)`	Deprecated.
`static String`	`defaultString(Object obj, String defaultString)`	Deprecated.
`static String`	`deleteWhitespace(String str)`	Deletes all whitespaces from a String.
`static String`	`difference(String s1, String s2)`	Compare two strings, and return the portion where they differ.
`static int`	`differenceAt(String s1, String s2)`	Compare two strings, and return the index at which the strings begin to differ.
`static boolean`	`equals(String str1, String str2)`	Deprecated.
`static boolean`	`equalsIgnoreCase(String str1, String str2)`	Compares two Strings, returning `true` if they are equal ignoring the case.
`static String`	`escape(String str)`	Escapes any values it finds into their String form.
`static String`	`escape(String source, char[] escapedChars, char escapeChar)`
`static String`	`escape(String source, char[] escapedChars, String escapePattern)`
`static String`	`getChomp(String str, String sep)`	Remove everything and return the last value of a supplied String, and everything after it from a String.
`static String`	`getNestedString(String str, String tag)`	Get the String that is nested in between two instances of the same String.
`static String`	`getNestedString(String str, String open, String close)`	Get the String that is nested in between two Strings.
`static String`	`getPrechomp(String str, String sep)`	Remove and return everything before the first value of a supplied String from another String.
`static int`	`indexOfAny(String str, String[] searchStrs)`	Find the first index of any of a set of potential substrings.
`static String`	`interpolate(String text, Map<?,?> namespace)`
`static boolean`	`isAlpha(String str)`	Checks if the String contains only unicode letters.
`static boolean`	`isAlphanumeric(String str)`	Checks if the String contains only unicode letters or digits.
`static boolean`	`isAlphanumericSpace(String str)`	Checks if the String contains only unicode letters, digits or space (`' '`).
`static boolean`	`isAlphaSpace(String str)`	Checks if the String contains only unicode letters and space (`' '`).
`static boolean`	`isBlank(String str)`	Checks if a String is whitespace, empty ("") or null.
`static boolean`	`isEmpty(String str)`	Checks if a (trimmed) String is `null` or empty.
`static boolean`	`isNotBlank(String str)`	Checks if a String is not empty (""), not null and not whitespace only.
`static boolean`	`isNotEmpty(String str)`	Checks if a String is non `null` and is not empty (`length > 0`).
`static boolean`	`isNumeric(String str)`	Checks if the String contains only unicode digits.
`static boolean`	`isNumericSpace(String str)`	Checks if the String contains only unicode digits or space (`' '`).
`static boolean`	`isWhitespace(String str)`	Checks if the String contains only whitespace.
`static String`	`join(Object[] array, String separator)`	Joins the elements of the provided array into a single String containing the provided list of elements.
`static String`	`join(Iterator<?> iterator, String separator)`	Joins the elements of the provided `Iterator` into a single String containing the provided elements.
`static int`	`lastIndexOfAny(String str, String[] searchStrs)`	Find the latest index of any of a set of potential substrings.
`static String`	`left(String str, int len)`	Gets the leftmost `n` characters of a String.
`static String`	`leftPad(String str, int size)`	Left pad a String with spaces.
`static String`	`leftPad(String str, int size, String delim)`	Left pad a String with a specified string.
`static String`	`lowerCase(String str)`	Convert a String to lower case, `null` String returns `null`.
`static String`	`lowercaseFirstLetter(String data)`
`static String`	`mid(String str, int pos, int len)`	Gets `n` characters from the middle of a String.
`static String`	`overlayString(String text, String overlay, int start, int end)`	Overlay a part of a String with another String.
`static String`	`prechomp(String str, String sep)`	Remove the first value of a supplied String, and everything before it from a String.
`static String`	`quoteAndEscape(String source, char quoteChar)`	Quote and escape a String with the given character, handling `null`.
`static String`	`quoteAndEscape(String source, char quoteChar, char[] quotingTriggers)`	Quote and escape a String with the given character, handling `null`.
`static String`	`quoteAndEscape(String source, char quoteChar, char[] escapedChars, char[] quotingTriggers, char escapeChar, boolean force)`
`static String`	`quoteAndEscape(String source, char quoteChar, char[] escapedChars, char[] quotingTriggers, String escapePattern, boolean force)`
`static String`	`quoteAndEscape(String source, char quoteChar, char[] escapedChars, char escapeChar, boolean force)`
`static String`	`removeAndHump(String data, String replaceThis)`
`static String`	`removeDuplicateWhitespace(String s)`	Remove all duplicate whitespace characters and line terminators are replaced with a single space.
`static String`	`repeat(String str, int repeat)`	Repeat a String `n` times to form a new string.
`static String`	`replace(String text, char repl, char with)`	Replace all occurrences of a char within another char.
`static String`	`replace(String text, char repl, char with, int max)`	Replace a char with another char inside a larger String, for the first `max` values of the search char.
`static String`	`replace(String text, String repl, String with)`	Replace all occurrences of a String within another String.
`static String`	`replace(String text, String repl, String with, int max)`	Replace a String with another String inside a larger String, for the first `max` values of the search String.
`static String`	`replaceOnce(String text, char repl, char with)`	Replace a char with another char inside a larger String, once.
`static String`	`replaceOnce(String text, String repl, String with)`	Replace a String with another String inside a larger String, once.
`static String`	`reverse(String str)`	Reverse a String.
`static String`	`reverseDelimitedString(String str, String delimiter)`	Reverses a String that is delimited by a specific character.
`static String`	`right(String str, int len)`	Gets the rightmost `n` characters of a String.
`static String`	`rightPad(String str, int size)`	Right pad a String with spaces.
`static String`	`rightPad(String str, int size, String delim)`	Right pad a String with a specified string.
`static String[]`	`split(String str)`	Splits the provided text into a array, using whitespace as the separator.
`static String[]`	`split(String text, String separator)`
`static String[]`	`split(String str, String separator, int max)`	Splits the provided text into a array, based on a given separator.
`static String`	`strip(String str)`	Remove whitespace from the front and back of a String.
`static String`	`strip(String str, String delim)`	Remove a specified String from the front and back of a String.
`static String[]`	`stripAll(String[] strs)`	Strip whitespace from the front and back of every String in the array.
`static String[]`	`stripAll(String[] strs, String delimiter)`	Strip the specified delimiter from the front and back of every String in the array.
`static String`	`stripEnd(String str, String strip)`	Strip any of a supplied String from the end of a String.
`static String`	`stripStart(String str, String strip)`	Strip any of a supplied String from the start of a String.
`static String`	`substring(String str, int start)`	Gets a substring from the specified string avoiding exceptions.
`static String`	`substring(String str, int start, int end)`	Gets a substring from the specified String avoiding exceptions.
`static String`	`swapCase(String str)`	Swaps the case of String.
`static String`	`trim(String str)`	Removes control characters, including whitespace, from both ends of this String, handling `null` by returning `null`.
`static String`	`uncapitalise(String str)`	Uncapitalise a String.
`static String`	`uncapitaliseAllWords(String str)`	Uncapitalise all the words in a string.
`static String`	`unifyLineSeparators(String s)`	Parses the given String and replaces all occurrences of '\n', '\r' and '\r\n' with the system line separator.
`static String`	`unifyLineSeparators(String s, String ls)`	Parses the given String and replaces all occurrences of '\n', '\r' and '\r\n' with the system line separator.
`static String`	`upperCase(String str)`	Convert a String to upper case, `null` String returns `null`.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - StringUtils
```
public StringUtils()
```
    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 manager to operate.
- Method Detail
  - clean
```
public static String clean(String str)
```
    Removes control characters, including whitespace, from both ends of this String, handling null by returning an empty String.
    
    Parameters:
    
    str - the String to check
    
    Returns:
    
    the trimmed text (never null)
    
    See Also:
    
    String.trim()
  - trim
```
public static String trim(String str)
```
    Removes control characters, including whitespace, from both ends of this String, handling null by returning null.
    
    Parameters:
    
    str - the String to check
    
    Returns:
    
    the trimmed text (or null)
    
    See Also:
    
    String.trim()
  - deleteWhitespace
```
public static String deleteWhitespace(String str)
```
    Deletes all whitespaces from a String.
    
    Whitespace is defined by Character.isWhitespace(char).
    
    Parameters:
    
    str - String target to delete whitespace from
    
    Returns:
    
    the String without whitespaces
  - isNotEmpty
```
public static boolean isNotEmpty(String str)
```
    Checks if a String is non null and is not empty (length > 0).
    
    Parameters:
    
    str - the String to check
    
    Returns:
    
    true if the String is non-null, and not length zero
  - isEmpty
```
public static boolean isEmpty(String str)
```
    Checks if a (trimmed) String is null or empty.
    
    Note: In future releases, this method will no longer trim the input string such that it works complementary to isNotEmpty(String). Code that wants to test for whitespace-only strings should be migrated to use isBlank(String) instead.
    
    Parameters:
    
    str - the String to check
    
    Returns:
    
    true if the String is null, or length zero once trimmed
  - isBlank
```
public static boolean isBlank(String str)
```
    Checks if a String is whitespace, empty ("") or null.
    
    StringUtils.isBlank(null) = true StringUtils.isBlank("") = true StringUtils.isBlank(" ") = true StringUtils.isBlank("bob") = false StringUtils.isBlank(" bob ") = false
    Parameters:
    
    str - the String to check, may be null
    
    Returns:
    
    true if the String is null, empty or whitespace
    
    Since:
    
    1.5.2
  - isNotBlank
```
public static boolean isNotBlank(String str)
```
    Checks if a String is not empty (""), not null and not whitespace only.
    
    StringUtils.isNotBlank(null) = false StringUtils.isNotBlank("") = false StringUtils.isNotBlank(" ") = false StringUtils.isNotBlank("bob") = true StringUtils.isNotBlank(" bob ") = true
    Parameters:
    
    str - the String to check, may be null
    
    Returns:
    
    true if the String is not empty and not null and not whitespace
    
    Since:
    
    1.5.2
  - equals
```
@Deprecated
public static boolean equals(String str1,
                             String str2)
```
    Deprecated.
    
    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.
    
    Parameters:
    
    str1 - the first string
    
    str2 - the second string
    
    Returns:
    
    true if the Strings are equal, case sensitive, or both null
    
    See Also:
    
    String.equals(Object), Objects.equals(Object, Object)
  - equalsIgnoreCase
```
public static boolean equalsIgnoreCase(String str1,
                                       String 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.
    
    Parameters:
    
    str1 - the first string
    
    str2 - the second string
    
    Returns:
    
    true if the Strings are equal, case insensitive, or both null
    
    See Also:
    
    String.equalsIgnoreCase(String)
  - indexOfAny
```
public static int indexOfAny(String str,
                             String[] searchStrs)
```
    Find the first index of any of a set of potential substrings.
    
    null String will return -1.
    
    Parameters:
    
    str - the String to check
    
    searchStrs - the Strings to search for
    
    Returns:
    
    the first index of any of the searchStrs in str
    
    Throws:
    
    NullPointerException - if any of searchStrs[i] is null
  - lastIndexOfAny
```
public static int lastIndexOfAny(String str,
                                 String[] searchStrs)
```
    Find the latest index of any of a set of potential substrings.
    
    null string will return -1.
    
    Parameters:
    
    str - the String to check
    
    searchStrs - the Strings to search for
    
    Returns:
    
    the last index of any of the Strings
    
    Throws:
    
    NullPointerException - if any of searchStrs[i] is null
  - substring
```
public static String substring(String str,
                               int start)
```
    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.
    
    Parameters:
    
    str - the String to get the substring from
    
    start - the position to start from, negative means count back from the end of the String by this many characters
    
    Returns:
    
    substring from start position
  - substring
```
public static String substring(String str,
                               int start,
                               int end)
```
    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.
    
    Parameters:
    
    str - the String to get the substring from
    
    start - the position to start from, negative means count back from the end of the string by this many characters
    
    end - the position to end at (exclusive), negative means count back from the end of the String by this many characters
    
    Returns:
    
    substring from start position to end position
  - left
```
public static String left(String str,
                          int len)
```
    Gets the leftmost n characters of a String.
    
    If n characters are not available, or the String is null, the String will be returned without an exception.
    
    Parameters:
    
    str - the String to get the leftmost characters from
    
    len - the length of the required String
    
    Returns:
    
    the leftmost characters
    
    Throws:
    
    IllegalArgumentException - if len is less than zero
  - right
```
public static String right(String str,
                           int len)
```
    Gets the rightmost n characters of a String.
    
    If n characters are not available, or the String is null, the String will be returned without an exception.
    
    Parameters:
    
    str - the String to get the rightmost characters from
    
    len - the length of the required String
    
    Returns:
    
    the leftmost characters
    
    Throws:
    
    IllegalArgumentException - if len is less than zero
  - mid
```
public static String mid(String str,
                         int pos,
                         int len)
```
    Gets n characters from the middle of a String.
    
    If n characters are not available, the remainder of the String will be returned without an exception. If the String is null, null will be returned.
    
    Parameters:
    
    str - the String to get the characters from
    
    pos - the position to start from
    
    len - the length of the required String
    
    Returns:
    
    the leftmost characters
    
    Throws:
    
    IndexOutOfBoundsException - if pos is out of bounds
    
    IllegalArgumentException - if len is less than zero
  - split
```
public static String[] split(String str)
```
    Splits the provided text into a array, using whitespace as the separator.
    
    The separator is not included in the returned String array.
    
    Parameters:
    
    str - the String to parse
    
    Returns:
    
    an array of parsed Strings
  - split
```
public static String[] split(String text,
                             String separator)
```
    Parameters:
    
    text - The string to parse.
    
    separator - Characters used as the delimiters. If null, splits on whitespace.
    
    Returns:
    
    an array of parsed Strings
  - split
```
public static String[] split(String str,
                             String separator,
                             int max)
```
    Splits the provided text into a array, based on a given separator.
    
    The separator is not included in the returned String array. The maximum number of splits to perform can be controlled. A null separator will cause parsing to be on whitespace.
    
    This is useful for quickly splitting a String directly into an array of tokens, instead of an enumeration of tokens (as StringTokenizer does).
    
    Parameters:
    
    str - The string to parse.
    
    separator - Characters used as the delimiters. If null, splits on whitespace.
    
    max - The maximum number of elements to include in the array. A zero or negative value implies no limit.
    
    Returns:
    
    an array of parsed Strings
  - concatenate
```
public static String concatenate(Object[] array)
```
    Concatenates elements of an array into a single String.
    
    The difference from join is that concatenate has no delimiter.
    
    Parameters:
    
    array - the array of values to concatenate.
    
    Returns:
    
    the concatenated string.
  - join
```
public static String join(Object[] array,
                          String separator)
```
    Joins the elements of the provided array into a single String containing the provided list of elements.
    
    No delimiter is added before or after the list. A null separator is the same as a blank String.
    
    Parameters:
    
    array - the array of values to join together
    
    separator - the separator character to use
    
    Returns:
    
    the joined String
  - join
```
public static String join(Iterator<?> iterator,
                          String separator)
```
    Joins the elements of the provided Iterator into a single String containing the provided elements.
    
    No delimiter is added before or after the list. A null separator is the same as a blank String.
    
    Parameters:
    
    iterator - the Iterator of values to join together
    
    separator - the separator character to use
    
    Returns:
    
    the joined String
  - replaceOnce
```
public static String replaceOnce(String text,
                                 char repl,
                                 char with)
```
    Replace a char with another char inside a larger String, once.
    
    A null reference passed to this method is a no-op.
    
    Parameters:
    
    text - text to search and replace in
    
    repl - char to search for
    
    with - char to replace with
    
    Returns:
    
    the text with any replacements processed
    
    See Also:
    
    replace(String text, char repl, char with, int max)
  - replace
```
public static String replace(String text,
                             char repl,
                             char with)
```
    Replace all occurrences of a char within another char.
    
    A null reference passed to this method is a no-op.
    
    Parameters:
    
    text - text to search and replace in
    
    repl - char to search for
    
    with - char to replace with
    
    Returns:
    
    the text with any replacements processed
    
    See Also:
    
    replace(String text, char repl, char with, int max)
  - replace
```
public static String replace(String text,
                             char repl,
                             char with,
                             int max)
```
    Replace a char with another char inside a larger String, for the first max values of the search char.
    
    A null reference passed to this method is a no-op.
    
    Parameters:
    
    text - text to search and replace in
    
    repl - char to search for
    
    with - char to replace with
    
    max - maximum number of values to replace, or -1 if no maximum
    
    Returns:
    
    the text with any replacements processed
  - replaceOnce
```
public static String replaceOnce(String text,
                                 String repl,
                                 String with)
```
    Replace a String with another String inside a larger String, once.
    
    A null reference passed to this method is a no-op.
    
    Parameters:
    
    text - text to search and replace in
    
    repl - String to search for
    
    with - String to replace with
    
    Returns:
    
    the text with any replacements processed
    
    See Also:
    
    replace(String text, String repl, String with, int max)
  - replace
```
public static String replace(String text,
                             String repl,
                             String with)
```
    Replace all occurrences of a String within another String.
    
    A null reference passed to this method is a no-op.
    
    Parameters:
    
    text - text to search and replace in
    
    repl - String to search for
    
    with - String to replace with
    
    Returns:
    
    the text with any replacements processed
    
    See Also:
    
    replace(String text, String repl, String with, int max)
  - replace
```
public static String replace(String text,
                             String repl,
                             String with,
                             int max)
```
    Replace a String with another String inside a larger String, for the first max values of the search String.
    
    A null reference passed to this method is a no-op.
    
    Parameters:
    
    text - text to search and replace in
    
    repl - String to search for
    
    with - String to replace with
    
    max - maximum number of values to replace, or -1 if no maximum
    
    Returns:
    
    the text with any replacements processed
  - overlayString
```
public static String overlayString(String text,
                                   String overlay,
                                   int start,
                                   int end)
```
    Overlay a part of a String with another String.
    
    Parameters:
    
    text - String to do overlaying in
    
    overlay - String to overlay
    
    start - int to start overlaying at
    
    end - int to stop overlaying before
    
    Returns:
    
    String with overlayed text
    
    Throws:
    
    NullPointerException - if text or overlay is null
  - center
```
public static String center(String str,
                            int size)
```
    Center a String in a larger String of size n.
    
    Uses spaces as the value to buffer the String with. Equivalent to center(str, size, " ").
    
    Parameters:
    
    str - String to center
    
    size - int size of new String
    
    Returns:
    
    String containing centered String
    
    Throws:
    
    NullPointerException - if str is null
  - center
```
public static String center(String str,
                            int size,
                            String delim)
```
    Center a String in a larger String of size n.
    
    Uses a supplied String as the value to buffer the String with.
    
    Parameters:
    
    str - String to center
    
    size - int size of new String
    
    delim - String to buffer the new String with
    
    Returns:
    
    String containing centered String
    
    Throws:
    
    NullPointerException - if str or delim is null
    
    ArithmeticException - if delim is the empty String
  - chomp
```
public static String chomp(String str)
```
    Remove the last newline, and everything after it from a String.
    
    Parameters:
    
    str - String to chomp the newline from
    
    Returns:
    
    String without chomped newline
    
    Throws:
    
    NullPointerException - if str is null
  - chomp
```
public static String chomp(String str,
                           String sep)
```
    Remove the last value of a supplied String, and everything after it from a String.
    
    Parameters:
    
    str - String to chomp from
    
    sep - String to chomp
    
    Returns:
    
    String without chomped ending
    
    Throws:
    
    NullPointerException - if str or sep is null
  - chompLast
```
public static String chompLast(String str)
```
    Remove a newline if and only if it is at the end of the supplied String.
    
    Parameters:
    
    str - String to chomp from
    
    Returns:
    
    String without chomped ending
    
    Throws:
    
    NullPointerException - if str is null
  - chompLast
```
public static String chompLast(String str,
                               String sep)
```
    Remove a value if and only if the String ends with that value.
    
    Parameters:
    
    str - String to chomp from
    
    sep - String to chomp
    
    Returns:
    
    String without chomped ending
    
    Throws:
    
    NullPointerException - if str or sep is null
  - getChomp
```
public static String getChomp(String str,
                              String sep)
```
    Remove everything and return the last value of a supplied String, and everything after it from a String.
    
    Parameters:
    
    str - String to chomp from
    
    sep - String to chomp
    
    Returns:
    
    String chomped
    
    Throws:
    
    NullPointerException - if str or sep is null
  - prechomp
```
public static String prechomp(String str,
                              String sep)
```
    Remove the first value of a supplied String, and everything before it from a String.
    
    Parameters:
    
    str - String to chomp from
    
    sep - String to chomp
    
    Returns:
    
    String without chomped beginning
    
    Throws:
    
    NullPointerException - if str or sep is null
  - getPrechomp
```
public static String getPrechomp(String str,
                                 String sep)
```
    Remove and return everything before the first value of a supplied String from another String.
    
    Parameters:
    
    str - String to chomp from
    
    sep - String to chomp
    
    Returns:
    
    String prechomped
    
    Throws:
    
    NullPointerException - if str or sep is null
  - chop
```
public static String chop(String str)
```
    Remove the last character from a String.
    
    If the String ends in \r\n, then remove both of them.
    
    Parameters:
    
    str - String to chop last character from
    
    Returns:
    
    String without last character
    
    Throws:
    
    NullPointerException - if str is null
  - chopNewline
```
public static String chopNewline(String str)
```
    Remove \n from end of a String if it's there. If a \r precedes it, then remove that too.
    
    Parameters:
    
    str - String to chop a newline from
    
    Returns:
    
    String without newline
    
    Throws:
    
    NullPointerException - if str is null
  - escape
```
public static String escape(String str)
```
    Escapes any values it finds into their String form.
    
    So a tab becomes the characters '\\' and 't'.
    
    Parameters:
    
    str - String to escape values in
    
    Returns:
    
    String with escaped values
    
    Throws:
    
    NullPointerException - if str is null
  - repeat
```
public static String repeat(String str,
                            int repeat)
```
    Repeat a String n times to form a new string.
    
    Parameters:
    
    str - String to repeat
    
    repeat - number of times to repeat str
    
    Returns:
    
    String with repeated String
    
    Throws:
    
    NegativeArraySizeException - if repeat < 0
    
    NullPointerException - if str is null
  - rightPad
```
public static String rightPad(String str,
                              int size)
```
    Right pad a String with spaces.
    
    The String is padded to the size of n.
    
    Parameters:
    
    str - String to repeat
    
    size - number of times to repeat str
    
    Returns:
    
    right padded String
    
    Throws:
    
    NullPointerException - if str is null
  - rightPad
```
public static String rightPad(String str,
                              int size,
                              String delim)
```
    Right pad a String with a specified string.
    
    The String is padded to the size of n.
    
    Parameters:
    
    str - String to pad out
    
    size - size to pad to
    
    delim - String to pad with
    
    Returns:
    
    right padded String
    
    Throws:
    
    NullPointerException - if str or delim is null
    
    ArithmeticException - if delim is the empty String
  - leftPad
```
public static String leftPad(String str,
                             int size)
```
    Left pad a String with spaces.
    
    The String is padded to the size of n.
    
    Parameters:
    
    str - String to pad out
    
    size - size to pad to
    
    Returns:
    
    left padded String
    
    Throws:
    
    NullPointerException - if str or delim is null
  - leftPad
```
public static String leftPad(String str,
                             int size,
                             String delim)
```
    Left pad a String with a specified string. Pad to a size of n.
    
    Parameters:
    
    str - String to pad out
    
    size - size to pad to
    
    delim - String to pad with
    
    Returns:
    
    left padded String
    
    Throws:
    
    NullPointerException - if str or delim is null
    
    ArithmeticException - if delim is the empty string
  - strip
```
public static String strip(String str)
```
    Remove whitespace from the front and back of a String.
    
    Parameters:
    
    str - the String to remove whitespace from
    
    Returns:
    
    the stripped String
  - strip
```
public static String strip(String str,
                           String delim)
```
    Remove a specified String from the front and back of a String.
    
    If whitespace is wanted to be removed, used the strip(java.lang.String) method.
    
    Parameters:
    
    str - the String to remove a string from
    
    delim - the String to remove at start and end
    
    Returns:
    
    the stripped String
  - stripAll
```
public static String[] stripAll(String[] strs)
```
    Strip whitespace from the front and back of every String in the array.
    
    Parameters:
    
    strs - the Strings to remove whitespace from
    
    Returns:
    
    the stripped Strings
  - stripAll
```
public static String[] stripAll(String[] strs,
                                String delimiter)
```
    Strip the specified delimiter from the front and back of every String in the array.
    
    Parameters:
    
    strs - the Strings to remove a String from
    
    delimiter - the String to remove at start and end
    
    Returns:
    
    the stripped Strings
  - stripEnd
```
public static String stripEnd(String str,
                              String strip)
```
    Strip any of a supplied String from the end of a String.
    
    If the strip String is null, whitespace is stripped.
    
    Parameters:
    
    str - the String to remove characters from
    
    strip - the String to remove
    
    Returns:
    
    the stripped String
  - stripStart
```
public static String stripStart(String str,
                                String strip)
```
    Strip any of a supplied String from the start of a String.
    
    If the strip String is null, whitespace is stripped.
    
    Parameters:
    
    str - the String to remove characters from
    
    strip - the String to remove
    
    Returns:
    
    the stripped String
  - upperCase
```
public static String upperCase(String str)
```
    Convert a String to upper case, null String returns null.
    
    Parameters:
    
    str - the String to uppercase
    
    Returns:
    
    the upper cased String
  - lowerCase
```
public static String lowerCase(String str)
```
    Convert a String to lower case, null String returns null.
    
    Parameters:
    
    str - the string to lowercase
    
    Returns:
    
    the lower cased String
  - uncapitalise
```
public static String uncapitalise(String str)
```
    Uncapitalise a String.
    
    That is, convert the first character into lower-case. null is returned as null.
    
    Parameters:
    
    str - the String to uncapitalise
    
    Returns:
    
    uncapitalised String
  - capitalise
```
public static String capitalise(String str)
```
    Capitalise a String.
    
    That is, convert the first character into title-case. null is returned as null.
    
    Parameters:
    
    str - the String to capitalise
    
    Returns:
    
    capitalised String
  - swapCase
```
public static String swapCase(String str)
```
    Swaps the case of String.
    
    Properly looks after making sure the start of words are Titlecase and not Uppercase.
    
    null is returned as null.
    
    Parameters:
    
    str - the String to swap the case of
    
    Returns:
    
    the modified String
  - capitaliseAllWords
```
public static String capitaliseAllWords(String str)
```
    Capitalise all the words in a String.
    
    Uses Character.isWhitespace(char) as a separator between words.
    
    null will return null.
    
    Parameters:
    
    str - the String to capitalise
    
    Returns:
    
    capitalised String
  - uncapitaliseAllWords
```
public static String uncapitaliseAllWords(String str)
```
    Uncapitalise all the words in a string.
    
    Uses Character.isWhitespace(char) as a separator between words.
    
    null will return null.
    
    Parameters:
    
    str - the string to uncapitalise
    
    Returns:
    
    uncapitalised string
  - getNestedString
```
public static String getNestedString(String str,
                                     String tag)
```
    Get the String that is nested in between two instances of the same String.
    
    If str is null, will return null.
    
    Parameters:
    
    str - the String containing nested-string
    
    tag - the String before and after nested-string
    
    Returns:
    
    the String that was nested, or null
    
    Throws:
    
    NullPointerException - if tag is null
  - getNestedString
```
public static String getNestedString(String str,
                                     String open,
                                     String close)
```
    Get the String that is nested in between two Strings.
    
    Parameters:
    
    str - the String containing nested-string
    
    open - the String before nested-string
    
    close - the String after nested-string
    
    Returns:
    
    the String that was nested, or null
    
    Throws:
    
    NullPointerException - if open or close is null
  - countMatches
```
public static int countMatches(String str,
                               String sub)
```
    How many times is the substring in the larger String.
    
    null returns 0.
    
    Parameters:
    
    str - the String to check
    
    sub - the substring to count
    
    Returns:
    
    the number of occurrences, 0 if the String is null
    
    Throws:
    
    NullPointerException - if sub is null
  - isAlpha
```
public static boolean isAlpha(String str)
```
    Checks if the String contains only unicode letters.
    
    null will return false. An empty String will return true.
    
    Parameters:
    
    str - the String to check
    
    Returns:
    
    true if only contains letters, and is non-null
  - isWhitespace
```
public static boolean isWhitespace(String str)
```
    Checks if the String contains only whitespace.
    
    null will return false. An empty String will return true.
    
    Parameters:
    
    str - the String to check
    
    Returns:
    
    true if only contains whitespace, and is non-null
  - isAlphaSpace
```
public static boolean isAlphaSpace(String str)
```
    Checks if the String contains only unicode letters and space (' ').
    
    null will return false. An empty String will return true.
    
    Parameters:
    
    str - the String to check
    
    Returns:
    
    true if only contains letters and space, and is non-null
  - isAlphanumeric
```
public static boolean isAlphanumeric(String str)
```
    Checks if the String contains only unicode letters or digits.
    
    null will return false. An empty String will return true.
    
    Parameters:
    
    str - the String to check
    
    Returns:
    
    true if only contains letters or digits, and is non-null
  - isAlphanumericSpace
```
public static boolean isAlphanumericSpace(String str)
```
    Checks if the String contains only unicode letters, digits or space (' ').
    
    null will return false. An empty String will return true.
    
    Parameters:
    
    str - the String to check
    
    Returns:
    
    true if only contains letters, digits or space, and is non-null
  - isNumeric
```
public static boolean isNumeric(String str)
```
    Checks if the String contains only unicode digits.
    
    null will return false. An empty String will return true.
    
    Parameters:
    
    str - the String to check
    
    Returns:
    
    true if only contains digits, and is non-null
  - isNumericSpace
```
public static boolean isNumericSpace(String str)
```
    Checks if the String contains only unicode digits or space (' ').
    
    null will return false. An empty String will return true.
    
    Parameters:
    
    str - the String to check
    
    Returns:
    
    true if only contains digits or space, and is non-null
  - defaultString
```
@Deprecated
public static String defaultString(Object obj)
```
    Deprecated.
    
    Returns either the passed in Object as a String, or, if the Object is null, an empty String.
    
    Parameters:
    
    obj - the Object to check
    
    Returns:
    
    the passed in Object's toString, or blank if it was null
    
    See Also:
    
    Objects.toString(Object, String)
  - defaultString
```
@Deprecated
public static String defaultString(Object obj,
                                   String defaultString)
```
    Deprecated.
    
    Returns either the passed in Object as a String, or, if the Object is null, a passed in default String.
    
    Parameters:
    
    obj - the Object to check
    
    defaultString - the default String to return if str is null
    
    Returns:
    
    the passed in string, or the default if it was null
    
    See Also:
    
    Objects.toString(Object, String)
  - reverse
```
public static String reverse(String str)
```
    Reverse a String.
    
    null String returns null.
    
    Parameters:
    
    str - the String to reverse
    
    Returns:
    
    the reversed String
  - reverseDelimitedString
```
public static String reverseDelimitedString(String str,
                                            String delimiter)
```
    Reverses a String that is delimited by a specific character.
    
    The Strings between the delimiters are not reversed. Thus java.lang.String becomes String.lang.java (if the delimiter is '.').
    
    Parameters:
    
    str - the String to reverse
    
    delimiter - the delimiter to use
    
    Returns:
    
    the reversed String
  - abbreviate
```
public static String abbreviate(String s,
                                int maxWidth)
```
    Parameters:
    
    s - string
    
    maxWidth - maximum length of result string
    
    Returns:
    
    Turn "Now is the time for all good men" into "Now is the time for..."
    Specifically:
    If str is less than max characters long, return it. Else abbreviate it to (substring(str, 0, max-3) + "..."). If maxWidth is less than 3, throw an IllegalArgumentException. In no case will it return a string of length greater than maxWidth.
  - abbreviate
```
public static String abbreviate(String s,
                                int offset,
                                int maxWidth)
```
    Parameters:
    
    s - string
    
    offset - left edge of source string
    
    maxWidth - maximum length of result string
    
    Returns:
    
    Turn "Now is the time for all good men" into "...is the time for..." Works like abbreviate(String, int), but allows you to specify a "left edge" offset. Note that this left edge is not necessarily going to be the leftmost character in the result, or the first character following the ellipses, but it will appear somewhere in the result. In no case will it return a string of length greater than maxWidth.
  - difference
```
public static String difference(String s1,
                                String s2)
```
    Compare two strings, and return the portion where they differ. (More precisely, return the remainder of the second string, starting from where it's different from the first.)
    E.g. strdiff("i am a machine", "i am a robot") -> "robot"
    
    Parameters:
    
    s1 - string
    
    s2 - string
    
    Returns:
    
    the portion of s2 where it differs from s1; returns the empty string ("") if they are equal
  - differenceAt
```
public static int differenceAt(String s1,
                               String s2)
```
    Compare two strings, and return the index at which the strings begin to differ.
    E.g. strdiff("i am a machine", "i am a robot") -> 7
    
    Parameters:
    
    s1 - string
    
    s2 - string
    
    Returns:
    
    the index where s2 and s1 begin to differ; -1 if they are equal
  - interpolate
```
public static String interpolate(String text,
                                 Map<?,?> namespace)
```
  - removeAndHump
```
public static String removeAndHump(String data,
                                   String replaceThis)
```
  - capitalizeFirstLetter
```
public static String capitalizeFirstLetter(String data)
```
  - lowercaseFirstLetter
```
public static String lowercaseFirstLetter(String data)
```
  - addAndDeHump
```
public static String addAndDeHump(String view)
```
  - quoteAndEscape
```
public static String quoteAndEscape(String source,
                                    char quoteChar)
```
    Quote and escape a String with the given character, handling null.
    
    StringUtils.quoteAndEscape(null, *) = null StringUtils.quoteAndEscape("", *) = "" StringUtils.quoteAndEscape("abc", '"') = abc StringUtils.quoteAndEscape("a\"bc", '"') = "a\"bc" StringUtils.quoteAndEscape("a\"bc", '\'') = 'a\"bc'
    Parameters:
    
    source - the source String
    
    quoteChar - the char used to quote
    
    Returns:
    
    the String quoted and escaped
    
    Since:
    
    1.5.1
    
    See Also:
    
    quoteAndEscape(String, char, char[], char[], char, boolean)
  - quoteAndEscape
```
public static String quoteAndEscape(String source,
                                    char quoteChar,
                                    char[] quotingTriggers)
```
    Quote and escape a String with the given character, handling null.
    
    Parameters:
    
    source - the source String
    
    quoteChar - the char used to quote
    
    quotingTriggers - chars generating a quote
    
    Returns:
    
    the String quoted and escaped
    
    Since:
    
    1.5.1
    
    See Also:
    
    quoteAndEscape(String, char, char[], char[], char, boolean)
  - quoteAndEscape
```
public static String quoteAndEscape(String source,
                                    char quoteChar,
                                    char[] escapedChars,
                                    char escapeChar,
                                    boolean force)
```
    Parameters:
    
    source - the source String
    
    quoteChar - the char used to quote
    
    escapedChars - chars to escape
    
    escapeChar - char used for escaping
    
    force - force the quoting
    
    Returns:
    
    the String quoted and escaped
    
    Since:
    
    1.5.1
    
    See Also:
    
    quoteAndEscape(String, char, char[], char[], char, boolean)
  - quoteAndEscape
```
public static String quoteAndEscape(String source,
                                    char quoteChar,
                                    char[] escapedChars,
                                    char[] quotingTriggers,
                                    char escapeChar,
                                    boolean force)
```
    Parameters:
    
    source - the source String
    
    quoteChar - the char used to quote
    
    escapedChars - chars to escape
    
    quotingTriggers - chars generating a quote
    
    escapeChar - char used for escaping
    
    force - force the quoting
    
    Returns:
    
    the String quoted and escaped
    
    Since:
    
    1.5.1
  - quoteAndEscape
```
public static String quoteAndEscape(String source,
                                    char quoteChar,
                                    char[] escapedChars,
                                    char[] quotingTriggers,
                                    String escapePattern,
                                    boolean force)
```
    Parameters:
    
    source - the source String
    
    quoteChar - the char used to quote
    
    escapedChars - chars to escape
    
    quotingTriggers - chars generating a quote
    
    escapePattern - pattern used for escaping
    
    force - force the quoting
    
    Returns:
    
    the String quoted and escaped
    
    Since:
    
    3.0.4
  - escape
```
public static String escape(String source,
                            char[] escapedChars,
                            char escapeChar)
```
    Parameters:
    
    source - the source String
    
    escapedChars - chars to escape
    
    escapeChar - char used for escaping
    
    Returns:
    
    the String escaped
    
    Since:
    
    1.5.1
  - escape
```
public static String escape(String source,
                            char[] escapedChars,
                            String escapePattern)
```
    Parameters:
    
    source - the source String
    
    escapedChars - chars to escape
    
    escapePattern - pattern used for escaping
    
    Returns:
    
    the String escaped
    
    Since:
    
    3.0.4
  - removeDuplicateWhitespace
```
public static String removeDuplicateWhitespace(String s)
```
    Remove all duplicate whitespace characters and line terminators are replaced with a single space.
    
    Parameters:
    
    s - a not null String
    
    Returns:
    
    a string with unique whitespace.
    
    Since:
    
    1.5.7
  - unifyLineSeparators
```
public static String unifyLineSeparators(String s)
```
    Parses the given String and replaces all occurrences of '\n', '\r' and '\r\n' with the system line separator.
    
    Parameters:
    
    s - a not null String
    
    Returns:
    
    a String that contains only System line separators.
    
    Since:
    
    1.5.7
    
    See Also:
    
    unifyLineSeparators(String, String)
  - unifyLineSeparators
```
public static String unifyLineSeparators(String s,
                                         String ls)
```
    Parses the given String and replaces all occurrences of '\n', '\r' and '\r\n' with the system line separator.
    
    Parameters:
    
    s - a not null String
    
    ls - the wanted line separator ("\n" on UNIX), if null using the System line separator.
    
    Returns:
    
    a String that contains only System line separators.
    
    Throws:
    
    IllegalArgumentException - if ls is not '\n', '\r' and '\r\n' characters.
    
    Since:
    
    1.5.7
  - contains
```
public static boolean contains(String str,
                               char searchChar)
```
    Checks if String contains a search character, handling null. This method uses 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
    Parameters:
    
    str - the String to check, may be null
    
    searchChar - the character to find
    
    Returns:
    
    true if the String contains the search character, false if not or null string input
    
    Since:
    
    1.5.7
  - contains
```
public static boolean contains(String str,
                               String searchStr)
```
    Checks if String contains a search String, handling null. This method uses String.indexOf(int).
    
    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
    Parameters:
    
    str - the String to check, may be null
    
    searchStr - the String to find, may be null
    
    Returns:
    
    true if the String contains the search String, false if not or null string input
    
    Since:
    
    1.5.7

Class StringUtils

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

StringUtils

Method Detail

clean

trim

deleteWhitespace

isNotEmpty

isEmpty

isBlank

isNotBlank

equals

equalsIgnoreCase

indexOfAny

lastIndexOfAny

substring

substring

left

right

mid

split

split

split

concatenate

join

join

replaceOnce

replace

replace

replaceOnce

replace

replace

overlayString

center

center

chomp

chomp

chompLast

chompLast

getChomp

prechomp

getPrechomp

chop

chopNewline

escape

repeat

rightPad

rightPad

leftPad

leftPad

strip

strip

stripAll

stripAll

stripEnd

stripStart

upperCase

lowerCase

uncapitalise

capitalise

swapCase

capitaliseAllWords

uncapitaliseAllWords

getNestedString

getNestedString

countMatches

isAlpha

isWhitespace

isAlphaSpace

isAlphanumeric

isAlphanumericSpace

isNumeric

isNumericSpace

defaultString

defaultString

reverse

reverseDelimitedString