正则表达式，一些例子

package cn.zhengze;

import java.util.ArrayList;
import java.util.Arrays;

public class zhengze {

/**
* @param args
*/
public static void main(String[] args) {

//test1();
//	test2();
test3();

}
public static void test1() {

String temp = "我我我.......我要学...学学学...编编编程程..";
temp=temp.replaceAll("\\.+", "");
temp=temp.replaceAll("(.)\\1+", "$1");
System.out.println(temp);
}
private static void test2() {
/*
* 对ip地址排序
*
*/
String temp = "192.168.1.200  17.1.10.10.10    3.3.50.3 127.0.0.1";
temp=temp.replaceAll("(\\d+)","00$1" );
temp =temp.replaceAll("0*(\\d{3})", "$1");

String[] ips =temp.split(" +");
Arrays.sort(ips);
for(String ip:ips)
{
System.out.println(ip.replaceAll("0*(\\d+)", "$1"));
}
/* 结果：
* 3.3.50.3
17.1.10.10.10
127.0.0.1
192.168.1.200
*/
}

private static void test3() {

/*
*  校检邮箱地址
*/
String  mail = "abc12@sina.com";
String regex="\\w+@[a-zA-Z0-9]+(\\.[a-zA-Z]{2,3}){1,3}";
boolean b =mail.matches(regex);
System.out.println(mail+":"+b);

}
}