Strings (The ZKoss Common Library 9.5.0.3 API)

java.lang.Object
- org.zkoss.lang.Strings

```
public class Strings
extends Object
```
String utilities and constants

Author:

tomyeh

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static class Strings.Result
The result of substring(java.lang.String, int, char).

Nested Classes
Modifier and Type	Class and Description
`static class`	`Strings.Result` The result of `substring(java.lang.String, int, char)`.

Field Summary

Fields
Modifier and Type Field and Description

static String EMPTY

static String ESCAPE_JAVASCRIPT
Used with escape(java.lang.String, java.lang.String) to escape a string in JavaScript.

Fields
Modifier and Type	Field and Description
`static String`	`EMPTY`
`static String`	`ESCAPE_JAVASCRIPT` Used with `escape(java.lang.String, java.lang.String)` to escape a string in JavaScript.

Constructor Summary

Constructors
Constructor and Description

Strings()

Constructors
Constructor and Description
`Strings()`

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static int`	`anyOf(String src, String delimiters, int from)` Returns the index that is one of delimiters, or the length if none of delimiter is found.
`static String`	`defaultIfEmpty(String value, String defaultValue)` Returns the passed value, or the default value if it is empty.
`static String`	`encode(int val)` Returns an encoded string, faster and shorter than Long.toHexString.
`static String`	`encode(long val)` Returns an encoded string, faster and shorter than Long.toHexString.
`static StringBuffer`	`encode(StringBuffer sb, int val)` Returns an encoded string buffer, faster and shorter than Integer.toHexString.
`static StringBuffer`	`encode(StringBuffer sb, long val)` Returns an encoded string buffer, faster and shorter than Long.toHexString.
`static StringBuffer`	`escape(StringBuffer dst, CharSequence src, String specials)` Escapes (a.k.a.
`static StringBuilder`	`escape(StringBuilder dst, CharSequence src, String specials)` Escapes (a.k.a.
`static String`	`escape(String src, String specials)` Escapes (a.k.a, quote) the special characters with backslash.
`static String`	`escapeJavaScript(String text)` Escapes (a.k.a.
`static int`	`indexOf(StringBuffer sb, char cc, int j)` Returns the index of the give character in the given string buffer, or -1 if not found.
`static boolean`	`isBlank(String s)` Returns true if the string is null or empty or pure blank.
`static boolean`	`isEmpty(String s)` Returns true if the string is null or empty.
`static <T> String`	`join(T[] array)` Joins the elements of the array into a single String separated by a comma.
`static <T> String`	`join(T[] array, char separator)` Joins the elements of the array into a single String separated by the given separator.
`static <T> String`	`join(T[] array, char separator, int startIndex, int endIndex)` Joins the elements of the array into a single String separated by the given separator from the startIndex to the endIndex.
`static int`	`lastAnyOf(String src, String delimiters, int from)` The backward version of `anyOf(java.lang.String, java.lang.String, int)`.
`static int`	`lastIndexOf(StringBuffer sb, char cc, int j)` Returns the last index of the give character in the given string buffer, or -1 if not found.
`static int`	`nextSeparator(String src, int from, char[] separators, boolean escBackslash, boolean escQuot, boolean quotAsSeparator)` Returns the next separator index in the src string.
`static int`	`nextSeparator(String src, int from, char[] separators, boolean escBackslash, boolean escQuot, boolean quotAsSeparator, boolean parenthesis)` Returns the next separator index in the src string.
`static Strings.Result`	`nextToken(String src, int from, char[] separators)` Returns the next token with unescape.
`static Strings.Result`	`nextToken(String src, int from, char[] separators, boolean escBackslash, boolean quotAsToken)` Returns the next token with additional options.
`static Strings.Result`	`nextToken(String src, int from, char[] separators, boolean escBackslash, boolean quotAsToken, boolean parenthesis)` Returns the next token with additional options.
`static int`	`nextWhitespace(CharSequence src, int from)` Returns the next whitespace.
`static int`	`skipWhitespaces(CharSequence src, int from)` Returns the next index after skipping whitespaces.
`static int`	`skipWhitespacesBackward(CharSequence src, int from)` The backward version of `skipWhitespaces(java.lang.CharSequence, int)`.
`static Strings.Result`	`substring(String src, int from, char until)` Returns the substring from the `from` index up to the `until` character or end-of-string.
`static Strings.Result`	`substring(String src, int from, char until, boolean escBackslash)` Returns the substring from the `from` index up to the `until` character or end-of-string.
`static String`	`toString(byte[] data)` Converts the given byte[] to UTF-8 string, if possible.
`static StringBuffer`	`trim(StringBuffer buf, int index)` Trims the string buffer by removing the leading and trailing whitespaces.
`static String`	`unescape(String s)` Un-escape the quoted string.

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

- Field Detail
  - ESCAPE_JAVASCRIPT
```
public static final String ESCAPE_JAVASCRIPT
```
    Used with escape(java.lang.String, java.lang.String) to escape a string in JavaScript. It assumes the string will be enclosed with a single quote.
    
    See Also:
    
    Constant Field Values
  - EMPTY
```
public static final String EMPTY
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - Strings
```
public Strings()
```
- Method Detail
  - isEmpty
```
public static final boolean isEmpty(String s)
```
    Returns true if the string is null or empty.
  - isBlank
```
public static final boolean isBlank(String s)
```
    Returns true if the string is null or empty or pure blank.
  - trim
```
public static final StringBuffer trim(StringBuffer buf,
                                      int index)
```
    Trims the string buffer by removing the leading and trailing whitespaces. Note: unlike String.trim(), you can specify the index of the first character to start trimming.
    Like String.trim(), a whitespace is a character that has a code not great than '\u0020' (the space character)
    
    Parameters:
    
    buf - the string buffer to trim the leading and trailing.
    
    index - the index of the first character to trim (i.e., consider as the leading character). If 0, it starts from the beginning.
    
    Returns:
    
    the same string buffer
    
    Since:
    
    3.0.4
  - encode
```
public static final StringBuffer encode(StringBuffer sb,
                                        int val)
```
    Returns an encoded string buffer, faster and shorter than Integer.toHexString. It uses numbers and lower-case letters only. Thus it is a valid variable name if prefix with an alphabet. At least one character is generated.
    It works even in system that is case-insensitive, such as IE.
    It is useful to generate a string to represent a number.
  - encode
```
public static final StringBuffer encode(StringBuffer sb,
                                        long val)
```
    Returns an encoded string buffer, faster and shorter than Long.toHexString. It uses numbers and lower-case letters only. Thus it is a valid variable name if prefix with an alphabet. At least one character is generated.
    It works even in system that is case-insensitive, such as IE.
    It is useful to generate a string to represent a number.
  - encode
```
public static final String encode(int val)
```
    Returns an encoded string, faster and shorter than Long.toHexString.
  - encode
```
public static final String encode(long val)
```
    Returns an encoded string, faster and shorter than Long.toHexString.
  - indexOf
```
public static final int indexOf(StringBuffer sb,
                                char cc,
                                int j)
```
    Returns the index of the give character in the given string buffer, or -1 if not found. It is equivalent to sb.indexOf(""+cc, j);, but faster.
    
    Since:
    
    5.0.3
  - lastIndexOf
```
public static final int lastIndexOf(StringBuffer sb,
                                    char cc,
                                    int j)
```
    Returns the last index of the give character in the given string buffer, or -1 if not found. It is equivalent to sb.lastIndexOf(""+cc, j);, but faster.
    
    Since:
    
    5.0.3
  - anyOf
```
public static final int anyOf(String src,
                              String delimiters,
                              int from)
```
    Returns the index that is one of delimiters, or the length if none of delimiter is found.
    Unlike String.indexOf(String, int), this method returns the first occurrence of any character in the delimiters.
    This method is optimized to use String.indexOf(char, int) if it found the length of delimiter is 1.
    
    Parameters:
    
    src - the source string to search
    
    from - the index to start the search from
    
    delimiters - the set of characters to search for
    
    Returns:
    
    the index that is one of delimiters. If return >= src.length(), it means no such delimiters
    
    See Also:
    
    lastAnyOf(java.lang.String, java.lang.String, int)
  - lastAnyOf
```
public static final int lastAnyOf(String src,
                                  String delimiters,
                                  int from)
```
    The backward version of anyOf(java.lang.String, java.lang.String, int).
    This method is optimized to use String.indexOf(char, int) if it found the length of delimiter is 1.
    
    Returns:
    
    the previous index that is one of delimiter. If it is negative, it means no delimiter in front of from
    
    See Also:
    
    anyOf(java.lang.String, java.lang.String, int)
  - skipWhitespaces
```
public static final int skipWhitespaces(CharSequence src,
                                        int from)
```
    Returns the next index after skipping whitespaces.
  - skipWhitespacesBackward
```
public static final int skipWhitespacesBackward(CharSequence src,
                                                int from)
```
    The backward version of skipWhitespaces(java.lang.CharSequence, int).
    
    Returns:
    
    the next index that is not a whitespace. If it is negative, it means no whitespace in front of it.
  - nextWhitespace
```
public static final int nextWhitespace(CharSequence src,
                                       int from)
```
    Returns the next whitespace.
  - escape
```
public static final String escape(String src,
                                  String specials)
```
    Escapes (a.k.a, quote) the special characters with backslash. It prefix a backslash to any characters specified in the specials argument.
    Note: specials usually contains '\\'.
    For example, Maps.parse(java.util.Map<? super java.lang.String, ? super java.lang.String>, java.lang.String, char, char) will un-quote backspace. Thus, if you want to preserve backslash, you have invoke escape(s, "\\") before calling Maps.parse().
    
    Parameters:
    
    src - the string to process. If null, null is returned.
    
    specials - a string of characters that shall be escaped/quoted To escape a string in JavaScript code snippet, you can use ESCAPE_JAVASCRIPT.
    
    See Also:
    
    unescape(java.lang.String)
  - escape
```
public static final StringBuffer escape(StringBuffer dst,
                                        CharSequence src,
                                        String specials)
```
    Escapes (a.k.a. quote) the special characters with backslash and appends it the specified string buffer.
    
    Parameters:
    
    dst - the destination buffer to append to.
    
    src - the source to escape from.
    
    specials - a string of characters that shall be escaped/quoted To escape a string in JavaScript code snippet, you can use ESCAPE_JAVASCRIPT.
    
    Since:
    
    5.0.0
  - escape
```
public static final StringBuilder escape(StringBuilder dst,
                                         CharSequence src,
                                         String specials)
```
    Escapes (a.k.a. quote) the special characters with backslash and appends it the specified string buffer.
    
    Parameters:
    
    dst - the destination buffer to append to.
    
    src - the source to escape from.
    
    specials - a string of characters that shall be escaped/quoted To escape a string in JavaScript code snippet, you can use ESCAPE_JAVASCRIPT.
    
    Since:
    
    8.0.0
  - escapeJavaScript
```
public static final String escapeJavaScript(String text)
```
    Escapes (a.k.a. quote) the special characters with backslash.
    Note: this implementation is referred from unbescape
    
    Since:
    
    8.0.0
  - unescape
```
public static final String unescape(String s)
```
    Un-escape the quoted string.
    
    See Also:
    
    escape(java.lang.String, java.lang.String)
  - substring
```
public static final Strings.Result substring(String src,
                                             int from,
                                             char until)
```
    Returns the substring from the from index up to the until character or end-of-string. Unlike String.subsring, it converts \f, \n, \t and \r. It doesn't handle u and x yet.
    
    Returns:
    
    the result (never null). Result.next is the position of the until character if found, or a number larger than length() if no such character.
  - substring
```
public static final Strings.Result substring(String src,
                                             int from,
                                             char until,
                                             boolean escBackslash)
```
    Returns the substring from the from index up to the until character or end-of-string.
    
    Parameters:
    
    escBackslash - whether to treat '\\' specially (as escape char) It doesn't handle u and x yet.
    
    Returns:
    
    the result (never null). Result.next is the position of the until character if found, or a number larger than length() if no such character. You can tell which case it is by examining Strings.Result.separator.
  - nextToken
```
public static final Strings.Result nextToken(String src,
                                             int from,
                                             char[] separators)
                                      throws IllegalSyntaxException
```
    Returns the next token with unescape.
    - It trims whitespaces before and after the token.
    - It handles both '\'' and '"'. All characters between them are considered as a token.
    - If nothing found before end-of-string, null is returned
    If a separator is found, it is returned in Strings.Result.separator.
    Throws:
    
    IllegalSyntaxException - if the quoted string is unclosed.
  - nextToken
```
public static final Strings.Result nextToken(String src,
                                             int from,
                                             char[] separators,
                                             boolean escBackslash,
                                             boolean quotAsToken)
                                      throws IllegalSyntaxException
```
    Returns the next token with additional options. It is the same as nextToken(src, from, separators, escBackslash, quotAsToken, false); Refer to nextToken(String, int, char[], boolean, boolean, boolean) for more information.
    
    Throws:
    
    IllegalSyntaxException - if the quoted string is unclosed.
    
    See Also:
    
    nextToken(String, int, char[], boolean, boolean, boolean)
  - nextToken
```
public static final Strings.Result nextToken(String src,
                                             int from,
                                             char[] separators,
                                             boolean escBackslash,
                                             boolean quotAsToken,
                                             boolean parenthesis)
                                      throws IllegalSyntaxException
```
    Returns the next token with additional options.
    - It trims whitespaces before and after the token.
    - If quotAsToken is true, all characters between quotations ('\'' or '"') are considered as a token.
    - If parenthesis is true, the separators and quotes inside a pair of parenthesis won't be treated specially. It is useful if EL expressions might be contained.
    - Consider '\\' as the escape char if escBackslash is true.
    - If nothing found before end-of-string, null is returned
    If a separator is found, it is returned in Strings.Result.separator.
    Parameters:
    
    escBackslash - whether to treat '\\' specially (as escape char) It doesn't handle u and x yet.
    
    quotAsToken - whether to treat characters inside '\'' or '"' as a token. Note: the quotes are excluded from the token.
    
    parenthesis - whether to ignore separators and quotes inside a pair of parentheses. Recognized parentheses include {}, [] or ().
    
    Throws:
    
    IllegalSyntaxException - if the quoted string is unclosed.
    
    Since:
    
    3.0.6
  - nextSeparator
```
public static int nextSeparator(String src,
                                int from,
                                char[] separators,
                                boolean escBackslash,
                                boolean escQuot,
                                boolean quotAsSeparator)
```
    Returns the next separator index in the src string.
    
    Parameters:
    
    escQuot - whether to escape characters inside quotations ('\'' or '"'). In other words, ignore separators inside quotations
    
    quotAsSeparator - whether to consider quotations as one of the separators
    
    Since:
    
    2.4.0
  - nextSeparator
```
public static int nextSeparator(String src,
                                int from,
                                char[] separators,
                                boolean escBackslash,
                                boolean escQuot,
                                boolean quotAsSeparator,
                                boolean parenthesis)
```
    Returns the next separator index in the src string.
    
    Parameters:
    
    escQuot - whether to escape characters inside quotations ('\'' or '"'). In other words, it specifies whether to ignore separators inside quotations
    
    quotAsSeparator - whether to consider quotations as one of the separators. If escQuot is true, quotAsSeparator is ignored.
    
    parenthesis - whether to ignore separators and quotes in side a pair of parentheses. Recognized parentheses include {}, [] or ().
    
    Since:
    
    3.0.6
  - join
```
public static final <T> String join(T[] array)
```
    Joins the elements of the array into a single String separated by a comma.
    
    Parameters:
    
    array -
    
    Since:
    
    8.0.0
  - join
```
public static final <T> String join(T[] array,
                                    char separator)
```
    Joins the elements of the array into a single String separated by the given separator.
    
    Parameters:
    
    array -
    
    separator -
    
    Since:
    
    8.0.0
  - join
```
public static final <T> String join(T[] array,
                                    char separator,
                                    int startIndex,
                                    int endIndex)
```
    Joins the elements of the array into a single String separated by the given separator from the startIndex to the endIndex.
    
    Parameters:
    
    array -
    
    separator -
    
    startIndex -
    
    endIndex -
    
    Since:
    
    8.0.0
  - toString
```
public static final String toString(byte[] data)
```
    Converts the given byte[] to UTF-8 string, if possible. Or return with the default charset.
    This is a method helper for JDK 5
    
    Since:
    
    8.0.2
  - defaultIfEmpty
```
public static final String defaultIfEmpty(String value,
                                          String defaultValue)
```
    Returns the passed value, or the default value if it is empty.
    
    Parameters:
    
    value - the value
    
    defaultValue - the default value
    
    Returns:
    
    value if not empty. defaultValue if empty.
    
    Since:
    
    9.5.0

Class Strings

Nested Class Summary

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

ESCAPE_JAVASCRIPT

EMPTY

Constructor Detail

Strings

Method Detail

isEmpty

isBlank

trim

encode

encode

encode

encode

indexOf

lastIndexOf

anyOf

lastAnyOf

skipWhitespaces

skipWhitespacesBackward

nextWhitespace

escape

escape

escape

escapeJavaScript

unescape

substring

substring

nextToken

nextToken

nextToken

nextSeparator

nextSeparator

join

join

join

toString

defaultIfEmpty