java.lang.Object
- org.parboiled.common.StringUtils

public final class StringUtils
extends Object

General utility methods for string manipulation.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method	Description
`static boolean`	`equalsIgnoreCase(String str1, String str2)`	Compares two Strings, returning `true` if they are equal ignoring the case.
`static String`	`escape(char c)`	Replaces carriage returns, newlines, tabs, formfeeds and the special chars defined in `Characters` with their respective escape sequences.
`static String`	`escape(String string)`	Replaces carriage returns, newlines, tabs, formfeeds and the special chars defined in `Characters` with their respective escape sequences.
`static boolean`	`isEmpty(String str)`	Checks if a String is empty ("") or null.
`static boolean`	`isNotEmpty(String str)`	Checks if a String is not empty ("") and not null.
`static String`	`join(Iterable iterable, String separator)`	Joins the elements of the provided `Iterable` into a single String containing the provided elements.
`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(Object[] array, String separator, int startIndex, int endIndex)`	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 String`	`left(String str, int len)`	Gets the leftmost `len` characters of a String.
`static int`	`length(String str)`	Gets a String's length or `0` if the String is `null`.
`static String`	`mid(String str, int pos, int len)`	Gets `len` characters from the middle of a String.
`static String`	`repeat(char c, int n)`	Creates a string consisting of n times the given character.
`static String`	`right(String str, int len)`	Gets the rightmost `len` characters of a String.
`static boolean`	`startsWith(String string, String prefix)`	Test whether a string starts with a given prefix, handling null values without exceptions.
`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.

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

- Method Detail
  - escape
```
public static String escape(String string)
```
    Replaces carriage returns, newlines, tabs, formfeeds and the special chars defined in Characters with their respective escape sequences.
    
    Parameters:
    
    string - the string
    
    Returns:
    
    the escaped string
  - escape
```
public static String escape(char c)
```
    Replaces carriage returns, newlines, tabs, formfeeds and the special chars defined in Characters with their respective escape sequences.
    
    Parameters:
    
    c - the character to escape
    
    Returns:
    
    the escaped string
  - repeat
```
public static String repeat(char c,
                            int n)
```
    Creates a string consisting of n times the given character.
    
    Parameters:
    
    c - the char
    
    n - the number of times to repeat
    
    Returns:
    
    the string
  - join
```
public static String join(Iterable iterable,
                          String separator)
```
    Joins the elements of the provided Iterable into a single String containing the provided elements.
    
    No delimiter is added before or after the list. A null separator is the same as an empty String ("").
    
    Parameters:
    
    iterable - the Iterable of values to join together, may be null
    
    separator - the separator character to use, null treated as ""
    
    Returns:
    
    the joined String, null if null iterator input
  - 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 an empty String ("").
    
    Parameters:
    
    iterator - the Iterator of values to join together, may be null
    
    separator - the separator character to use, null treated as ""
    
    Returns:
    
    the joined String, null if null iterator input
  - 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 an empty String (""). Null objects or empty strings within the array are represented by empty strings.
    
    StringUtils.join(null, *) = null StringUtils.join([], *) = "" StringUtils.join([null], *) = "" StringUtils.join(["a", "b", "c"], "--") = "a--b--c" StringUtils.join(["a", "b", "c"], null) = "abc" StringUtils.join(["a", "b", "c"], "") = "abc" StringUtils.join([null, "", "a"], ',') = ",,a"
    Parameters:
    
    array - the array of values to join together, may be null
    
    separator - the separator character to use, null treated as ""
    
    Returns:
    
    the joined String, null if null array input
  - join
```
public static String join(Object[] array,
                          String separator,
                          int startIndex,
                          int endIndex)
```
    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 an empty String (""). Null objects or empty strings within the array are represented by empty strings.
    
    StringUtils.join(null, *) = null StringUtils.join([], *) = "" StringUtils.join([null], *) = "" StringUtils.join(["a", "b", "c"], "--") = "a--b--c" StringUtils.join(["a", "b", "c"], null) = "abc" StringUtils.join(["a", "b", "c"], "") = "abc" StringUtils.join([null, "", "a"], ',') = ",,a"
    Parameters:
    
    array - the array of values to join together, may be null
    
    separator - the separator character to use, null treated as ""
    
    startIndex - the first index to start joining from. It is an error to pass in an end index past the end of the array
    
    endIndex - the index to stop joining from (exclusive). It is an error to pass in an end index past the end of the array
    
    Returns:
    
    the joined String, null if null array input
  - isEmpty
```
public static boolean isEmpty(String str)
```
    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
    Parameters:
    
    str - the String to check, may be null
    
    Returns:
    
    true if the String is empty or null
  - isNotEmpty
```
public static boolean isNotEmpty(String str)
```
    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
    Parameters:
    
    str - the String to check, may be null
    
    Returns:
    
    true if the String is not empty and not null
  - length
```
public static int length(String str)
```
    Gets a String's length or 0 if the String is null.
    
    Parameters:
    
    str - a String or null
    
    Returns:
    
    String length or 0 if the String is null.
  - 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.
    
    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
    Parameters:
    
    str1 - the first String, may be null
    
    str2 - the second String, may be null
    
    Returns:
    
    true if the Strings are equal, case insensitive, or both null
  - startsWith
```
public static boolean startsWith(String string,
                                 String prefix)
```
    Test whether a string starts with a given prefix, handling null values without exceptions. StringUtils.startsWith(null, null) = false StringUtils.startsWith(null, "abc") = false StringUtils.startsWith("abc", null) = true StringUtils.startsWith("abc", "ab") = true StringUtils.startsWith("abc", "abc") = true
    
    Parameters:
    
    string - the string
    
    prefix - the prefix
    
    Returns:
    
    true if string starts with prefix
  - 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.
    
    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"
    Parameters:
    
    str - the String to get the substring from, may be null
    
    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, null if null String input
  - 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.
    
    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"
    Parameters:
    
    str - the String to get the substring from, may be null
    
    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 positon, null if null String input
  - left
```
public static String left(String str,
                          int len)
```
    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 exception is thrown 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"
    Parameters:
    
    str - the String to get the leftmost characters from, may be null
    
    len - the length of the required String, must be zero or positive
    
    Returns:
    
    the leftmost characters, null if null String input
  - right
```
public static String right(String str,
                           int 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 exception is thrown 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"
    Parameters:
    
    str - the String to get the rightmost characters from, may be null
    
    len - the length of the required String, must be zero or positive
    
    Returns:
    
    the rightmost characters, null if null String input
  - mid
```
public static String mid(String str,
                         int pos,
                         int 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 exception is thrown if len is negative.
    
    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"
    Parameters:
    
    str - the String to get the characters from, may be null
    
    pos - the position to start from, negative treated as zero
    
    len - the length of the required String, must be zero or positive
    
    Returns:
    
    the middle characters, null if null String input

Class StringUtils

Method Summary

Methods inherited from class java.lang.Object

Method Detail

escape

escape

repeat

join

join

join

join

isEmpty

isNotEmpty

length

equalsIgnoreCase

startsWith

substring

substring

left

right

mid