com.feilong.core.util

Class RegexUtil

java.lang.Object

com.feilong.core.util.RegexUtil

public final class RegexUtil
extends Object

正则表达式工具类.

Since:

1.0.0, jdk1.4

Author:

feilong

See Also:

"RegexPattern", Pattern, Matcher, String.matches(String)

Method Summary

Methods

Modifier and Type	Method and Description
static Pattern	buildPattern(String regexPattern, int flags) 如果cache中有,那么直接返回, 如果没有构造一个并塞到cache中.
static Map<Integer,String>	group(String regexPattern, CharSequence input) 返回在以前匹配操作期间由给定组捕获的输入子序列.
static String	group(String regexPattern, CharSequence input, int groupNo) 返回在以前匹配操作期间由给定组捕获的输入子序列.
static boolean	matches(String regexPattern, CharSequence input) 编译给定正则表达式 regexPattern ,并尝试将给定输入 input 与其匹配.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

matches

public static boolean matches(String regexPattern,
              CharSequence input)

编译给定正则表达式 regexPattern ,并尝试将给定输入 input 与其匹配.

Pattern.matches(String, CharSequence) 等价于getMatcher(String, CharSequence).matches();

Parameters:

regexPattern - 正则表达式字符串,pls use "RegexPattern"

input - The character sequence to be matched,support String,StringBuffer,StringBuilder... and so on

Returns:

如果 regexPattern 是null,抛出 NullPointerException
如果 input 是null,返回 false
如果input 符合 regex的正则表达式格式,返回true,否则返回 false;

Since:

1.0.7, 1.13.2 change, if input is null, return false from NPE

See Also:

getMatcher(String, CharSequence), Matcher.matches(), Pattern.matches(String, CharSequence)

group

public static Map<Integer,String> group(String regexPattern,
                        CharSequence input)

返回在以前匹配操作期间由给定组捕获的输入子序列.

对于匹配器 m、输入序列 s 和组索引 g,表达式 m.group(g) 和 s.substring(m.start(g), m.end(g))是等效的.
捕获组是从 1开始从左到右的索引.组0表示整个模式,因此表达式 m.group(0)等效于 m.group().

示例:

 String regexPattern = "(.*?)@(.*?)";
 String email = "feilong@163.com";
 
 RegexUtil.group(regexPattern, email);
 

返回:

    0 feilong@163.com
    1 feilong
    2 163.com
 

Parameters:

regexPattern - 正则表达式模式,比如 (.*?)@(.*?)

input - 需要被group的字符串,比如 feilong@163.com,support String,StringBuffer,StringBuilder... and so on

Returns:

如果 regexPattern 是null,抛出 NullPointerException
如果 input 是null,抛出 NullPointerException
如果 匹配不了,返回 Collections.emptyMap()

Since:

1.0.7

See Also:

getMatcher(String, CharSequence), Matcher.group(int)

group

public static String group(String regexPattern,
           CharSequence input,
           int groupNo)

返回在以前匹配操作期间由给定组捕获的输入子序列.

对于匹配器 m、输入序列 s 和组索引 g,表达式 m.group(g) 和 s.substring(m.start(g), m.end(g))是等效的.
捕获组是从 1开始从左到右的索引.组0表示整个模式,因此表达式 m.group(0)等效于 m.group().

示例:

 
 String regexPattern = "(.*?)@(.*?)";
 String email = "feilong@163.com";
 
 RegexUtil.group(regexPattern, email, 1);//feilong
 RegexUtil.group(regexPattern, email, 2);//163.com
 
 

Parameters:

regexPattern - 正则表达式模式,比如 (.*?)@(.*?)

input - 需要被group的字符串,比如 feilong@163.com,support String,StringBuffer,StringBuilder... and so on

groupNo - 组号,从0开始

Returns:

如果 regexPattern 是null,抛出 NullPointerException
如果 input 是null,抛出 NullPointerException
如果 input < 0 ,抛出 IllegalArgumentException

Since:

1.0.7

See Also:

getMatcher(String, CharSequence), Matcher.group(int)

buildPattern

public static Pattern buildPattern(String regexPattern,
                   int flags)

如果cache中有,那么直接返回, 如果没有构造一个并塞到cache中.

Parameters:

regexPattern - the regex pattern

flags - the flags

Returns:

the pattern

Since:

1.10.6