java正则表达式-案例代码

转载请注明出处：http://blog.youkuaiyun.com/droyon/article/details/8635735

jdk在线api：http://docs.oracle.com/javase/7/docs/api/index.html，选择java.utils.regex，可以查看Pattern类的介绍。

.：任意字符

[abc]:含有a,b，c的任意一个字符

[^abc]：除了a,b,c之外的任意字符

[a-zA-Z]：a到z,A到Z的任意字符

[abc[hij]]：a,b,c,h,i,j中的任意字符

[a-z&&hij]:匹配h,i,j中的任何一个交集

\s:空白符，空格，tab键，换行，换页，回车

\S:非空白符

\d:数字0到9

\D:非数字

\w:词字符[a-zA-Z0-9]

\W:非词字符

^:一行的开始

&：一行的结束

\b：词的边界

\B：非词的边界

\G:前一个匹配的结束

代码下载

PatternTest.java//字符串匹配正则表达式

public class PatternTest {
	public static void main(String args[]){
		for(String s:new String[]{"HelloWorld","[a-zA-Z]elloWorld","[a-zA-Z]+"
				,"[A-Z]?elloWorld","Hello.*"}){
			System.out.println("是否匹配："+"HelloWorld".matches(s));
		}
	}
}

结果：

是否匹配：true
是否匹配：true
是否匹配：true
是否匹配：true
是否匹配：true

PatternMatcher.java//Pattern、Matcher类使用    abc+以及（abc）+的区别，+代表一个或多个 ？代表存在一个或一个没有

import java.util.regex.Matcher;
import java.util.regex.Pattern;


public class PatternMatcher {
	public static void main(String args[]){
		String s = "abcabcabcabchijabcccccc";
		String[] match = new String[]{"abc+","(abc)+"}; 
		for(String m:match){
			System.out.println("regex args is:"+m);
			Pattern pattern = Pattern.compile(m);
			Matcher matcher = pattern.matcher(s);
			while(matcher.find()){
				System.out.println("匹配到内容："+matcher.group()+"在字符串的："
						+matcher.start()+"-"+matcher.end());
			}
			System.out.println("---------------------------");
		}
	}
}

结果：

regex args is:abc+
匹配到内容：abc在字符串的：0-3
匹配到内容：abc在字符串的：3-6
匹配到内容：abc在字符串的：6-9
匹配到内容：abc在字符串的：9-12
匹配到内容：abcccccc在字符串的：15-23
---------------------------
regex args is:(abc)+
匹配到内容：abcabcabcabc在字符串的：0-12
匹配到内容：abc在字符串的：15-18
---------------------------

PatternGroup.java// 正则表达式 A（B（CD））E，Matcher.groupCount为正则表达式的级别。那么,Matcher.group(0) = ABCDE ,Matcher.group(1) = BCD,Matcher.group(2) = CD.Matcher.start代表开始匹配的位置，Matcher.end代表结束匹配的位置。

import java.util.regex.Matcher;
import java.util.regex.Pattern;


public class PatternGroup {
	public static void main(String args[]){
		String s = "abchabcabchabdabcabcabcabcabch";
		Pattern pattern = Pattern.compile("(abc((abc)+h))");
		Matcher matcher = pattern.matcher(s);
		System.out.println(matcher.groupCount());
		while(matcher.find()){
			for(int j=0;j<=matcher.groupCount();j++){
				System.out.println("group,级别:"+j+".结果为："+matcher.group(j)+"--start-end:"+matcher.start()+"-"+matcher.end());
			}
			System.out.println("-----------------------");
		}
	}
}

结果：
3
group,级别:0.结果为：abcabch--start-end:4-11
group,级别:1.结果为：abcabch--start-end:4-11
group,级别:2.结果为：abch--start-end:4-11
group,级别:3.结果为：abc--start-end:4-11
-----------------------
group,级别:0.结果为：abcabcabcabcabch--start-end:14-30
group,级别:1.结果为：abcabcabcabcabch--start-end:14-30
group,级别:2.结果为：abcabcabcabch--start-end:14-30
group,级别:3.结果为：abc--start-end:14-30
-----------------------

PatternFlag.java//常用flag有：Pattern.CASE_INSENSITIVE,Pattern.MULTILINE,Pattern.DOTALL

import java.util.regex.Matcher;
import java.util.regex.Pattern;


public class PatternFlag {
	public static void main(String args[]){
		String s = "Java is good language!\n"
				+"JAVA is good one you choose.\n"
				+"java,we all use it.";
		Pattern pattern = Pattern.compile("^java",Pattern.CASE_INSENSITIVE|Pattern.MULTILINE);
		Matcher matcher = pattern.matcher(s);
		while(matcher.find()){
			System.out.println("匹配结果："+matcher.group()+".start-end:"+matcher.start()+"-"+matcher.end());
		}
	}
}

结果：

匹配结果：Java.start-end:0-4
匹配结果：JAVA.start-end:23-27
匹配结果：java.start-end:52-56

PatternSplit.java//split的用法

import java.util.Arrays;
import java.util.regex.Matcher;
import java.util.regex.Pattern;


public class PatternSplit {
	public static void main(String args[]){
		String s = "Java is good language!\n"
				+"JAVA is good one you choose.\n"
				+"java,we all use it.";
		Pattern pattern = Pattern.compile("^java",Pattern.CASE_INSENSITIVE|Pattern.MULTILINE);
		Matcher matcher = pattern.matcher(s);
//		while(matcher.find()){
//			System.out.println("匹配结果："+matcher.group()+".start-end:"+matcher.start()+"-"+matcher.end());
//		}
		System.out.println(Arrays.toString(pattern.split(s)));
		System.out.println("数组长度为："+pattern.split(s).length);
		for(String arr:pattern.split(s)){
			System.out.println("数组内容为："+arr);
		}
	}
}

测试结果：

[,  is good language!
,  is good one you choose.
, ,we all use it.]
数组长度为：4
数组内容为：
数组内容为： is good language!
数组内容为： is good one you choose.
数组内容为：,we all use it.

PatternReplace.java//replace的用法

import java.util.regex.Matcher;
import java.util.regex.Pattern;


public class PatternReplace {
	public static void main(String args[]){
		String s = "***java is a good language!";
		System.out.println("字符串："+s);
		
		String s1 = s.replaceAll(" {1,}", "-");
		System.out.println("替换空格为-："+s1);
		
		String s2 = s.replaceAll("(?m)^\\*{1,}", "");
		System.out.println("替换字符串开头的*："+s2);
		
		Pattern pattern = Pattern.compile("[aeiou]");
		Matcher matcher = pattern.matcher(s);
		StringBuffer sb = new StringBuffer();
		while(matcher.find()){
			matcher.appendReplacement(sb, matcher.group().toUpperCase());
		}
		System.out.println("替换字符串为："+sb.toString());
	}
}

结果为：

字符串：***java is a good language!
替换空格为-：***java-is-a-good-language!
替换字符串开头的*：java is a good language!
替换字符串为：***jAvA Is A gOOd lAngUAgE