获取 模式Pattren 和匹配器 Matcher

Matcher matcher=pattern.matcher("aaa");

模式Pattren 和匹配器 Matcher的获取

public static void main(String[] args){
  //获取模式Pattern
  Pattern pattern=Pattern.compile("a*b*");
  //获取匹配器Matcher
  Matcher matcher=pattern.matcher("aaa");


  boolean b=matcher.matches();
  System.out.print(b);

获取字符串中长度为3的单词

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

/**
* Created by hanshan on 2016/12/29.
*/
public class Matcher和Pattern2 {
    public static void main(String[] args){
        String s="wo ai wo de jia,tom loves his jia too";
        Pattern pattern=Pattern.compile("\\b\\w{3}\\b");
        Matcher matcher=pattern.matcher(s);
    /*    boolean b=matcher.find();
        System.out.print(b);
        String result=matcher.group();
        System.out.print(result);*/
    while(matcher.find()){
        String ans=matcher.group();
        System.out.print(ans+"  ");
    }
        // 注意：一定要先find()，然后才能group()
        // IllegalStateException: No match found
        // String ss = m.group();
        // System.out.println(ss);
}
}