StringUtils (jprotobuf 2.4.15 API)

java.lang.Object
- com.baidu.bjf.remoting.protobuf.utils.StringUtils

```
public class StringUtils
extends Object
```
String utility class.

从以下版本开始:

1.2.5

作者:

xiemalin

字段概要

字段
限定符和类型字段和说明

static String EMPTY
The empty String "".

static String EMPTY_STRING

字段
限定符和类型	字段和说明
`static String`	`EMPTY` The empty String `""`.
`static String`	`EMPTY_STRING`

构造器概要

构造器
构造器和说明

StringUtils()

构造器
构造器和说明
`StringUtils()`

方法概要

所有方法静态方法具体方法已过时的方法
限定符和类型	方法和说明
`static String`	`capitalize(String str)` Capitalizes a String changing the first letter to title case as per `Character.toTitleCase(char)`.
`static boolean`	`endsWith(String str, String suffix)` Check if a String ends with a specified suffix.
`static boolean`	`endsWithIgnoreCase(String str, String suffix)` Case insensitive check if a String ends with a specified suffix.
`static String`	`escapeBytes(byte[] input)` Like `#escapeBytes(ByteString)`, but used for byte array.
`static String`	`escapeJava(String str)` Escapes the characters in a `String` using Java String rules.
`static void`	`escapeJava(Writer out, String str)` Escapes the characters in a `String` using Java String rules to a `Writer`.
`static boolean`	`isEmpty(Object[] array)` Checks if an array of Objects is empty or `null`.
`static boolean`	`isEmpty(String str)` Checks if a String is empty ("") or null.
`static String`	`removeEnd(String str, String remove)` Removes a substring only if it is at the end of a source string, otherwise returns the source string.
`static String`	`removeEndIgnoreCase(String str, String remove)` Case insensitive removal of a substring if it is at the end of a source string, otherwise returns the source string.
`static String`	`removeStart(String str, String remove)` Removes a substring only if it is at the begining of a source string, otherwise returns the source string.
`static String`	`removeStartIgnoreCase(String str, String remove)` Case insensitive removal of a substring if it is at the begining of a source string, otherwise returns the source string.
`static String[]`	`split(String str)` Splits the provided text into an array, using whitespace as the separator.
`static String[]`	`split(String str, char separatorChar)` Splits the provided text into an array, separator specified.
`static String[]`	`split(String str, String separatorChars)` Splits the provided text into an array, separators specified.
`static String[]`	`split(String str, String separatorChars, int max)` Splits the provided text into an array with a maximum length, separators specified.
`static String[]`	`splitByWholeSeparator(String str, String separator)` Splits the provided text into an array, separator string specified.
`static String[]`	`splitByWholeSeparator(String str, String separator, int max)` Splits the provided text into an array, separator string specified.
`static String[]`	`splitByWholeSeparatorPreserveAllTokens(String str, String separator)` Splits the provided text into an array, separator string specified.
`static String[]`	`splitByWholeSeparatorPreserveAllTokens(String str, String separator, int max)` Splits the provided text into an array, separator string specified.
`static boolean`	`startsWith(String str, String prefix)` Check if a String starts with a specified prefix.
`static boolean`	`startsWithAny(String string, String[] searchStrings)` Check if a String starts with any of an array of specified strings.
`static boolean`	`startsWithIgnoreCase(String str, String prefix)` Case insensitive check if a String starts with a specified prefix.
`static int`	`stringToInt(String str, int defaultValue)` 已过时。 Use `toInt(String, int)` This method will be removed in Commons Lang 3.0
`static String`	`substringAfterLast(String str, String separator)` Gets the substring after the last occurrence of a separator.
`static String`	`substringBefore(String str, String separator)` Gets the substring before the first occurrence of a separator.
`static String`	`substringBeforeLast(String str, String separator)` Gets the substring before the last occurrence of a separator.
`static int`	`toInt(String str)` Convert a `String` to an `int`, returning `zero` if the conversion fails.
`static int`	`toInt(String str, int defaultValue)` Convert a `String` to an `int`, returning a default value if the conversion fails.
`static long`	`toLong(String str)` Convert a `String` to an `long`, returning a default value if the conversion fails.
`static long`	`toLong(String str, long defaultValue)` Convert a `String` to an `long`, returning a default value if the conversion fails.
`static String`	`toLowerCase(String str)` To lower case.
`static String`	`trimToEmpty(String str)` 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`.
`static String`	`uncapitalize(String str)` Uncapitalizes a String, changing the first character to lower case as per `Character.toLowerCase(int)`.
`static String`	`unescapeJava(String str)` Unescapes any Java literals found in the `String`.
`static void`	`unescapeJava(Writer out, String str)` Unescapes any Java literals found in the `String` to a `Writer`.

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 字段详细资料
  - EMPTY_STRING
```
public static final String EMPTY_STRING
```
    另请参阅:
    
    常量字段值
  - EMPTY
```
public static final String EMPTY
```
    The empty String "".
    
    从以下版本开始:
    
    2.0
    
    另请参阅:
    
    常量字段值
- 构造器详细资料
  - StringUtils
```
public StringUtils()
```
- 方法详细资料
  - endsWith
```
public static boolean endsWith(String str,
                               String suffix)
```
    Check if a String ends with a specified suffix.
    
    nulls are handled without exceptions. Two null references are considered to be equal. The comparison is case sensitive.
```
 StringUtils.endsWith(null, null)      = true
 StringUtils.endsWith(null, "abcdef")  = false
 StringUtils.endsWith("def", null)     = false
 StringUtils.endsWith("def", "abcdef") = true
 StringUtils.endsWith("def", "ABCDEF") = false
 
```
    参数:
    
    str - the String to check, may be null
    
    suffix - the suffix to find, may be null
    
    返回:
    
    true if the String ends with the suffix, case sensitive, or both null
    
    从以下版本开始:
    
    2.4
    
    另请参阅:
    
    String.endsWith(String)
  - endsWithIgnoreCase
```
public static boolean endsWithIgnoreCase(String str,
                                         String suffix)
```
    Case insensitive check if a String ends with a specified suffix.
    
    nulls are handled without exceptions. Two null references are considered to be equal. The comparison is case insensitive.
```
 StringUtils.endsWithIgnoreCase(null, null)      = true
 StringUtils.endsWithIgnoreCase(null, "abcdef")  = false
 StringUtils.endsWithIgnoreCase("def", null)     = false
 StringUtils.endsWithIgnoreCase("def", "abcdef") = true
 StringUtils.endsWithIgnoreCase("def", "ABCDEF") = false
 
```
    参数:
    
    str - the String to check, may be null
    
    suffix - the suffix to find, may be null
    
    返回:
    
    true if the String ends with the suffix, case insensitive, or both null
    
    从以下版本开始:
    
    2.4
    
    另请参阅:
    
    String.endsWith(String)
  - removeEnd
```
public static String removeEnd(String str,
                               String remove)
```
    Removes a substring only if it is at the end of a source string, otherwise returns the source string.
    
    A null source string will return null. An empty ("") source string will return the empty string. A null search string will return the source string.
```
 StringUtils.removeEnd(null, *)      = null
 StringUtils.removeEnd("", *)        = ""
 StringUtils.removeEnd(*, null)      = *
 StringUtils.removeEnd("www.domain.com", ".com.")  = "www.domain.com"
 StringUtils.removeEnd("www.domain.com", ".com")   = "www.domain"
 StringUtils.removeEnd("www.domain.com", "domain") = "www.domain.com"
 StringUtils.removeEnd("abc", "")    = "abc"
 
```
    参数:
    
    str - the source String to search, may be null
    
    remove - the String to search for and remove, may be null
    
    返回:
    
    the substring with the string removed if found, null if null String input
    
    从以下版本开始:
    
    2.1
  - removeEndIgnoreCase
```
public static String removeEndIgnoreCase(String str,
                                         String remove)
```
    Case insensitive removal of a substring if it is at the end of a source string, otherwise returns the source string.
    
    A null source string will return null. An empty ("") source string will return the empty string. A null search string will return the source string.
```
 StringUtils.removeEnd(null, *)      = null
 StringUtils.removeEnd("", *)        = ""
 StringUtils.removeEnd(*, null)      = *
 StringUtils.removeEnd("www.domain.com", ".com.")  = "www.domain.com."
 StringUtils.removeEnd("www.domain.com", ".com")   = "www.domain"
 StringUtils.removeEnd("www.domain.com", "domain") = "www.domain.com"
 StringUtils.removeEnd("abc", "")    = "abc"
 
```
    参数:
    
    str - the source String to search, may be null
    
    remove - the String to search for (case insensitive) and remove, may be null
    
    返回:
    
    the substring with the string removed if found, null if null String input
    
    从以下版本开始:
    
    2.4
  - 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
 
```
    NOTE: This method changed in Lang version 2.0. It no longer trims the String. That functionality is available in isBlank().
    参数:
    
    str - the String to check, may be null
    
    返回:
    
    true if the String is empty or null
  - removeStart
```
public static String removeStart(String str,
                                 String remove)
```
    Removes a substring only if it is at the begining of a source string, otherwise returns the source string.
    
    A null source string will return null. An empty ("") source string will return the empty string. A null search string will return the source string.
```
 StringUtils.removeStart(null, *)      = null
 StringUtils.removeStart("", *)        = ""
 StringUtils.removeStart(*, null)      = *
 StringUtils.removeStart("www.domain.com", "www.")   = "domain.com"
 StringUtils.removeStart("domain.com", "www.")       = "domain.com"
 StringUtils.removeStart("www.domain.com", "domain") = "www.domain.com"
 StringUtils.removeStart("abc", "")    = "abc"
 
```
    参数:
    
    str - the source String to search, may be null
    
    remove - the String to search for and remove, may be null
    
    返回:
    
    the substring with the string removed if found, null if null String input
    
    从以下版本开始:
    
    2.1
  - removeStartIgnoreCase
```
public static String removeStartIgnoreCase(String str,
                                           String remove)
```
    Case insensitive removal of a substring if it is at the begining of a source string, otherwise returns the source string.
    
    A null source string will return null. An empty ("") source string will return the empty string. A null search string will return the source string.
```
 StringUtils.removeStartIgnoreCase(null, *)      = null
 StringUtils.removeStartIgnoreCase("", *)        = ""
 StringUtils.removeStartIgnoreCase(*, null)      = *
 StringUtils.removeStartIgnoreCase("www.domain.com", "www.")   = "domain.com"
 StringUtils.removeStartIgnoreCase("www.domain.com", "WWW.")   = "domain.com"
 StringUtils.removeStartIgnoreCase("domain.com", "www.")       = "domain.com"
 StringUtils.removeStartIgnoreCase("www.domain.com", "domain") = "www.domain.com"
 StringUtils.removeStartIgnoreCase("abc", "")    = "abc"
 
```
    参数:
    
    str - the source String to search, may be null
    
    remove - the String to search for (case insensitive) and remove, may be null
    
    返回:
    
    the substring with the string removed if found, null if null String input
    
    从以下版本开始:
    
    2.4
  - startsWith
```
public static boolean startsWith(String str,
                                 String prefix)
```
    Check if a String starts with a specified prefix.
    
    nulls are handled without exceptions. Two null references are considered to be equal. The comparison is case sensitive.
```
 StringUtils.startsWith(null, null)      = true
 StringUtils.startsWith(null, "abcdef")  = false
 StringUtils.startsWith("abc", null)     = false
 StringUtils.startsWith("abc", "abcdef") = true
 StringUtils.startsWith("abc", "ABCDEF") = false
 
```
    参数:
    
    str - the String to check, may be null
    
    prefix - the prefix to find, may be null
    
    返回:
    
    true if the String starts with the prefix, case sensitive, or both null
    
    从以下版本开始:
    
    2.4
    
    另请参阅:
    
    String.startsWith(String)
  - startsWithAny
```
public static boolean startsWithAny(String string,
                                    String[] searchStrings)
```
    Check if a String starts with any of an array of specified strings.
```
 StringUtils.startsWithAny(null, null)      = false
 StringUtils.startsWithAny(null, new String[] {"abc"})  = false
 StringUtils.startsWithAny("abcxyz", null)     = false
 StringUtils.startsWithAny("abcxyz", new String[] {""}) = false
 StringUtils.startsWithAny("abcxyz", new String[] {"abc"}) = true
 StringUtils.startsWithAny("abcxyz", new String[] {null, "xyz", "abc"}) = true
 
```
    参数:
    
    string - the String to check, may be null
    
    searchStrings - the Strings to find, may be null or empty
    
    返回:
    
    true if the String starts with any of the the prefixes, case insensitive, or both null
    
    从以下版本开始:
    
    2.5
    
    另请参阅:
    
    startsWith(String, String)
  - startsWithIgnoreCase
```
public static boolean startsWithIgnoreCase(String str,
                                           String prefix)
```
    Case insensitive check if a String starts with a specified prefix.
    
    nulls are handled without exceptions. Two null references are considered to be equal. The comparison is case insensitive.
```
 StringUtils.startsWithIgnoreCase(null, null)      = true
 StringUtils.startsWithIgnoreCase(null, "abcdef")  = false
 StringUtils.startsWithIgnoreCase("abc", null)     = false
 StringUtils.startsWithIgnoreCase("abc", "abcdef") = true
 StringUtils.startsWithIgnoreCase("abc", "ABCDEF") = true
 
```
    参数:
    
    str - the String to check, may be null
    
    prefix - the prefix to find, may be null
    
    返回:
    
    true if the String starts with the prefix, case insensitive, or both null
    
    从以下版本开始:
    
    2.4
    
    另请参阅:
    
    String.startsWith(String)
  - substringBefore
```
public static String substringBefore(String str,
                                     String separator)
```
    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.
```
 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"
 
```
    参数:
    
    str - the String to get a substring from, may be null
    
    separator - the String to search for, may be null
    
    返回:
    
    the substring before the first occurrence of the separator, null if null String input
    
    从以下版本开始:
    
    2.0
  - substringBeforeLast
```
public static String substringBeforeLast(String str,
                                         String separator)
```
    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.
```
 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"
 
```
    参数:
    
    str - the String to get a substring from, may be null
    
    separator - the String to search for, may be null
    
    返回:
    
    the substring before the last occurrence of the separator, null if null String input
    
    从以下版本开始:
    
    2.0
  - substringAfterLast
```
public static String substringAfterLast(String str,
                                        String separator)
```
    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.
```
 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")     = ""
 
```
    参数:
    
    str - the String to get a substring from, may be null
    
    separator - the String to search for, may be null
    
    返回:
    
    the substring after the last occurrence of the separator, null if null String input
    
    从以下版本开始:
    
    2.0
  - capitalize
```
public static String capitalize(String str)
```
    Capitalizes a String changing the first letter to title case as per Character.toTitleCase(char). No other letters are changed.
    
    For a word based algorithm, see WordUtils#capitalize(String). A null input String returns null.
```
 StringUtils.capitalize(null)  = null
 StringUtils.capitalize("")    = ""
 StringUtils.capitalize("cat") = "Cat"
 StringUtils.capitalize("cAt") = "CAt"
 
```
    参数:
    
    str - the String to capitalize, may be null
    
    返回:
    
    the capitalized String, null if null String input
    
    从以下版本开始:
    
    2.0
    
    另请参阅:
    
    WordUtils#capitalize(String), uncapitalize(String)
  - escapeJava
```
public static String escapeJava(String str)
```
    Escapes the characters in a String using Java String rules.
    
    Deals correctly with quotes and control-chars (tab, backslash, cr, ff, etc.)
    
    So a tab becomes the characters '\\' and 't'.
    
    The only difference between Java strings and JavaScript strings is that in JavaScript, a single quote must be escaped.
    
    Example:
```
 input string: He didn't say, "Stop!"
 output string: He didn't say, \"Stop!\"
 
```
    参数:
    
    str - String to escape values in, may be null
    
    返回:
    
    String with escaped values, null if null string input
  - escapeJava
```
public static void escapeJava(Writer out,
                              String str)
                       throws IOException
```
    Escapes the characters in a String using Java String rules to a Writer.
    
    A null string input has no effect.
    
    参数:
    
    out - Writer to write escaped string into
    
    str - String to escape values in, may be null
    
    抛出:
    
    IllegalArgumentException - if the Writer is null
    
    IOException - if error occurs on underlying Writer
    
    另请参阅:
    
    escapeJava(java.lang.String)
  - unescapeJava
```
public static String unescapeJava(String str)
```
    Unescapes any Java literals found in the String. For example, it will turn a sequence of '\' and 'n' into a newline character, unless the '\' is preceded by another '\'.
    
    参数:
    
    str - the String to unescape, may be null
    
    返回:
    
    a new unescaped String, null if null string input
  - unescapeJava
```
public static void unescapeJava(Writer out,
                                String str)
                         throws IOException
```
    Unescapes any Java literals found in the String to a Writer.
    
    For example, it will turn a sequence of '\' and 'n' into a newline character, unless the '\' is preceded by another '\'.
    
    A null string input has no effect.
    
    参数:
    
    out - the Writer used to output unescaped characters
    
    str - the String to unescape, may be null
    
    抛出:
    
    IllegalArgumentException - if the Writer is null
    
    IOException - if error occurs on underlying Writer
  - split
```
public static String[] split(String str)
```
    Splits the provided text into an array, using whitespace as the separator. Whitespace is defined by Character.isWhitespace(char).
    
    The separator is not included in the returned String array. Adjacent separators are treated as one separator. For more control over the split use the StrTokenizer class.
    
    A null input String returns null.
```
 StringUtils.split(null)       = null
 StringUtils.split("")         = []
 StringUtils.split("abc def")  = ["abc", "def"]
 StringUtils.split("abc  def") = ["abc", "def"]
 StringUtils.split(" abc ")    = ["abc"]
 
```
    参数:
    
    str - the String to parse, may be null
    
    返回:
    
    an array of parsed Strings, null if null String input
  - split
```
public static String[] split(String str,
                             char separatorChar)
```
    Splits the provided text into an array, separator specified. This is an alternative to using StringTokenizer.
    
    The separator is not included in the returned String array. Adjacent separators are treated as one separator. For more control over the split use the StrTokenizer class.
    
    A null input String returns null.
```
 StringUtils.split(null, *)         = null
 StringUtils.split("", *)           = []
 StringUtils.split("a.b.c", '.')    = ["a", "b", "c"]
 StringUtils.split("a..b.c", '.')   = ["a", "b", "c"]
 StringUtils.split("a:b:c", '.')    = ["a:b:c"]
 StringUtils.split("a b c", ' ')    = ["a", "b", "c"]
 
```
    参数:
    
    str - the String to parse, may be null
    
    separatorChar - the character used as the delimiter
    
    返回:
    
    an array of parsed Strings, null if null String input
    
    从以下版本开始:
    
    2.0
  - split
```
public static String[] split(String str,
                             String separatorChars)
```
    Splits the provided text into an array, separators specified. This is an alternative to using StringTokenizer.
    
    The separator is not included in the returned String array. Adjacent separators are treated as one separator. For more control over the split use the StrTokenizer class.
    
    A null input String returns null. A null separatorChars splits on whitespace.
```
 StringUtils.split(null, *)         = null
 StringUtils.split("", *)           = []
 StringUtils.split("abc def", null) = ["abc", "def"]
 StringUtils.split("abc def", " ")  = ["abc", "def"]
 StringUtils.split("abc  def", " ") = ["abc", "def"]
 StringUtils.split("ab:cd:ef", ":") = ["ab", "cd", "ef"]
 
```
    参数:
    
    str - the String to parse, may be null
    
    separatorChars - the characters used as the delimiters, null splits on whitespace
    
    返回:
    
    an array of parsed Strings, null if null String input
  - split
```
public static String[] split(String str,
                             String separatorChars,
                             int max)
```
    Splits the provided text into an array with a maximum length, separators specified.
    
    The separator is not included in the returned String array. Adjacent separators are treated as one separator.
    
    A null input String returns null. A null separatorChars splits on whitespace.
    
    If more than max delimited substrings are found, the last returned string includes all characters after the first max - 1 returned strings (including separator characters).
```
 StringUtils.split(null, *, *)            = null
 StringUtils.split("", *, *)              = []
 StringUtils.split("ab de fg", null, 0)   = ["ab", "cd", "ef"]
 StringUtils.split("ab   de fg", null, 0) = ["ab", "cd", "ef"]
 StringUtils.split("ab:cd:ef", ":", 0)    = ["ab", "cd", "ef"]
 StringUtils.split("ab:cd:ef", ":", 2)    = ["ab", "cd:ef"]
 
```
    参数:
    
    str - the String to parse, may be null
    
    separatorChars - the characters used as the delimiters, null splits on whitespace
    
    max - the maximum number of elements to include in the array. A zero or negative value implies no limit
    
    返回:
    
    an array of parsed Strings, null if null String input
  - splitByWholeSeparator
```
public static String[] splitByWholeSeparator(String str,
                                             String separator)
```
    Splits the provided text into an array, separator string specified.
    
    The separator(s) will not be included in the returned String array. Adjacent separators are treated as one separator.
    
    A null input String returns null. A null separator splits on whitespace.
```
 StringUtils.splitByWholeSeparator(null, *)               = null
 StringUtils.splitByWholeSeparator("", *)                 = []
 StringUtils.splitByWholeSeparator("ab de fg", null)      = ["ab", "de", "fg"]
 StringUtils.splitByWholeSeparator("ab   de fg", null)    = ["ab", "de", "fg"]
 StringUtils.splitByWholeSeparator("ab:cd:ef", ":")       = ["ab", "cd", "ef"]
 StringUtils.splitByWholeSeparator("ab-!-cd-!-ef", "-!-") = ["ab", "cd", "ef"]
 
```
    参数:
    
    str - the String to parse, may be null
    
    separator - String containing the String to be used as a delimiter, null splits on whitespace
    
    返回:
    
    an array of parsed Strings, null if null String was input
  - splitByWholeSeparator
```
public static String[] splitByWholeSeparator(String str,
                                             String separator,
                                             int max)
```
    Splits the provided text into an array, separator string specified. Returns a maximum of max substrings.
    
    The separator(s) will not be included in the returned String array. Adjacent separators are treated as one separator.
    
    A null input String returns null. A null separator splits on whitespace.
```
 StringUtils.splitByWholeSeparator(null, *, *)               = null
 StringUtils.splitByWholeSeparator("", *, *)                 = []
 StringUtils.splitByWholeSeparator("ab de fg", null, 0)      = ["ab", "de", "fg"]
 StringUtils.splitByWholeSeparator("ab   de fg", null, 0)    = ["ab", "de", "fg"]
 StringUtils.splitByWholeSeparator("ab:cd:ef", ":", 2)       = ["ab", "cd:ef"]
 StringUtils.splitByWholeSeparator("ab-!-cd-!-ef", "-!-", 5) = ["ab", "cd", "ef"]
 StringUtils.splitByWholeSeparator("ab-!-cd-!-ef", "-!-", 2) = ["ab", "cd-!-ef"]
 
```
    参数:
    
    str - the String to parse, may be null
    
    separator - String containing the String to be used as a delimiter, null splits on whitespace
    
    max - the maximum number of elements to include in the returned array. A zero or negative value implies no limit.
    
    返回:
    
    an array of parsed Strings, null if null String was input
  - splitByWholeSeparatorPreserveAllTokens
```
public static String[] splitByWholeSeparatorPreserveAllTokens(String str,
                                                              String separator)
```
    Splits the provided text into an array, separator string specified.
    
    The separator is not included in the returned String array. Adjacent separators are treated as separators for empty tokens. For more control over the split use the StrTokenizer class.
    
    A null input String returns null. A null separator splits on whitespace.
```
 StringUtils.splitByWholeSeparatorPreserveAllTokens(null, *)               = null
 StringUtils.splitByWholeSeparatorPreserveAllTokens("", *)                 = []
 StringUtils.splitByWholeSeparatorPreserveAllTokens("ab de fg", null)      = ["ab", "de", "fg"]
 StringUtils.splitByWholeSeparatorPreserveAllTokens("ab   de fg", null)    = ["ab", "", "", "de", "fg"]
 StringUtils.splitByWholeSeparatorPreserveAllTokens("ab:cd:ef", ":")       = ["ab", "cd", "ef"]
 StringUtils.splitByWholeSeparatorPreserveAllTokens("ab-!-cd-!-ef", "-!-") = ["ab", "cd", "ef"]
 
```
    参数:
    
    str - the String to parse, may be null
    
    separator - String containing the String to be used as a delimiter, null splits on whitespace
    
    返回:
    
    an array of parsed Strings, null if null String was input
    
    从以下版本开始:
    
    2.4
  - splitByWholeSeparatorPreserveAllTokens
```
public static String[] splitByWholeSeparatorPreserveAllTokens(String str,
                                                              String separator,
                                                              int max)
```
    Splits the provided text into an array, separator string specified. Returns a maximum of max substrings.
    
    The separator is not included in the returned String array. Adjacent separators are treated as separators for empty tokens. For more control over the split use the StrTokenizer class.
    
    A null input String returns null. A null separator splits on whitespace.
```
 StringUtils.splitByWholeSeparatorPreserveAllTokens(null, *, *)               = null
 StringUtils.splitByWholeSeparatorPreserveAllTokens("", *, *)                 = []
 StringUtils.splitByWholeSeparatorPreserveAllTokens("ab de fg", null, 0)      = ["ab", "de", "fg"]
 StringUtils.splitByWholeSeparatorPreserveAllTokens("ab   de fg", null, 0)    = ["ab", "", "", "de", "fg"]
 StringUtils.splitByWholeSeparatorPreserveAllTokens("ab:cd:ef", ":", 2)       = ["ab", "cd:ef"]
 StringUtils.splitByWholeSeparatorPreserveAllTokens("ab-!-cd-!-ef", "-!-", 5) = ["ab", "cd", "ef"]
 StringUtils.splitByWholeSeparatorPreserveAllTokens("ab-!-cd-!-ef", "-!-", 2) = ["ab", "cd-!-ef"]
 
```
    参数:
    
    str - the String to parse, may be null
    
    separator - String containing the String to be used as a delimiter, null splits on whitespace
    
    max - the maximum number of elements to include in the returned array. A zero or negative value implies no limit.
    
    返回:
    
    an array of parsed Strings, null if null String was input
    
    从以下版本开始:
    
    2.4
  - escapeBytes
```
public static String escapeBytes(byte[] input)
```
    Like #escapeBytes(ByteString), but used for byte array.
  - toInt
```
public static int toInt(String str)
```
    Convert a String to an int, returning zero if the conversion fails.
    
    If the string is null, zero is returned.
```
   NumberUtils.toInt(null) = 0
   NumberUtils.toInt("")   = 0
   NumberUtils.toInt("1")  = 1
 
```
    参数:
    
    str - the string to convert, may be null
    
    返回:
    
    the int represented by the string, or zero if conversion fails
    
    从以下版本开始:
    
    2.1
  - stringToInt
```
public static int stringToInt(String str,
                              int defaultValue)
```
    已过时。 Use toInt(String, int) This method will be removed in Commons Lang 3.0
    Convert a String to an int, returning a default value if the conversion fails.
    
    If the string is null, the default value is returned.
```
   NumberUtils.stringToInt(null, 1) = 1
   NumberUtils.stringToInt("", 1)   = 1
   NumberUtils.stringToInt("1", 0)  = 1
 
```
    参数:
    
    str - the string to convert, may be null
    
    defaultValue - the default value
    
    返回:
    
    the int represented by the string, or the default if conversion fails
  - toInt
```
public static int toInt(String str,
                        int defaultValue)
```
    Convert a String to an int, returning a default value if the conversion fails.
    
    If the string is null, the default value is returned.
```
   NumberUtils.toInt(null, 1) = 1
   NumberUtils.toInt("", 1)   = 1
   NumberUtils.toInt("1", 0)  = 1
 
```
    参数:
    
    str - the string to convert, may be null
    
    defaultValue - the default value
    
    返回:
    
    the int represented by the string, or the default if conversion fails
    
    从以下版本开始:
    
    2.1
  - toLong
```
public static long toLong(String str)
```
    Convert a String to an long, returning a default value if the conversion fails.
    
    If the string is null, the default value is returned.
```
   NumberUtils.toLong(null) = 0
   NumberUtils.toLong("")   = 0
   NumberUtils.toLong("1")  = 1
 
```
    参数:
    
    str - the string to convert, may be null
    
    返回:
    
    the long represented by the string, or the default if conversion fails
    
    从以下版本开始:
    
    2.1
  - toLong
```
public static long toLong(String str,
                          long defaultValue)
```
    Convert a String to an long, returning a default value if the conversion fails.
    
    If the string is null, the default value is returned.
```
   NumberUtils.toLong(null, 1) = 1
   NumberUtils.toLong("", 1)   = 1
   NumberUtils.toLong("1", 0)  = 1
 
```
    参数:
    
    str - the string to convert, may be null
    
    defaultValue - the default value
    
    返回:
    
    the long represented by the string, or the default if conversion fails
    
    从以下版本开始:
    
    2.1
  - trimToEmpty
```
public static String trimToEmpty(String str)
```
    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 String.trim(). Trim removes start and end characters <= 32. To strip whitespace use #stripToEmpty(String).
```
 StringUtils.trimToEmpty(null)          = ""
 StringUtils.trimToEmpty("")            = ""
 StringUtils.trimToEmpty("     ")       = ""
 StringUtils.trimToEmpty("abc")         = "abc"
 StringUtils.trimToEmpty("    abc    ") = "abc"
 
```
    参数:
    
    str - the String to be trimmed, may be null
    
    返回:
    
    the trimmed String, or an empty String if null input
    
    从以下版本开始:
    
    2.0
  - uncapitalize
```
public static String uncapitalize(String str)
```
    Uncapitalizes a String, changing the first character to lower case as per Character.toLowerCase(int). No other characters are changed.
    
    For a word based algorithm, see org.apache.commons.lang3.text.WordUtils#uncapitalize(String). A null input String returns null.
```
 StringUtils.uncapitalize(null)  = null
 StringUtils.uncapitalize("")    = ""
 StringUtils.uncapitalize("cat") = "cat"
 StringUtils.uncapitalize("Cat") = "cat"
 StringUtils.uncapitalize("CAT") = "cAT"
 
```
    参数:
    
    str - the String to uncapitalize, may be null
    
    返回:
    
    the uncapitalized String, null if null String input
    
    从以下版本开始:
    
    2.0
    
    另请参阅:
    
    org.apache.commons.lang3.text.WordUtils#uncapitalize(String), capitalize(String)
  - toLowerCase
```
public static String toLowerCase(String str)
```
    To lower case.
    
    参数:
    
    str - the str
    
    返回:
    
    the string
  - isEmpty
```
public static boolean isEmpty(Object[] array)
```
    Checks if an array of Objects is empty or null.
    
    参数:
    
    array - the array to test
    
    返回:
    
    true if the array is empty or null
    
    从以下版本开始:
    
    2.1

类 StringUtils

字段概要

构造器概要

方法概要

从类继承的方法 java.lang.Object

字段详细资料

EMPTY_STRING

EMPTY

构造器详细资料

StringUtils

方法详细资料

endsWith

endsWithIgnoreCase

removeEnd

removeEndIgnoreCase

isEmpty

removeStart

removeStartIgnoreCase

startsWith

startsWithAny

startsWithIgnoreCase

substringBefore

substringBeforeLast

substringAfterLast

capitalize

escapeJava

escapeJava

unescapeJava

unescapeJava

split

split

split

split

splitByWholeSeparator

splitByWholeSeparator

splitByWholeSeparatorPreserveAllTokens

splitByWholeSeparatorPreserveAllTokens

escapeBytes

toInt

stringToInt

toInt

toLong

toLong

trimToEmpty

uncapitalize

toLowerCase

isEmpty