遍历Map集合

例1:

package Test15;

import java.util.HashMap;

import java.util.HashSet;

import java.util.Iterator;

import java.util.Map;

import java.util.Set;

import java.util.Map.Entry;

//Map集合遍历

public class Test {

    private Map<String, String> map = new HashMap<String, String>();

    public static void main(String[] args) {

       Test t=new Test();

       t.setValue();

       t.method3();

    }

    //为map赋值

    public void setValue(){

       map.put("name", "张三");

       map.put("sex", "男");   

    }

    //方法1

    public void method1(){

       Set<String> set = new HashSet<String>();

       set = map.keySet(); // 获得map中所有Key

       for (String s : set) {

           System.out.println(map.get(s));

       }

    }

    //方法2

    public void method2(){

       Iterator<String> iterator=map.keySet().iterator(); //返回所有key

       while(iterator.hasNext()){

           String key=iterator.next();

           System.out.println(key+": "+map.get(key));

       }

    }

    //方法3

    public void method3(){

       Set<Entry<String,String>> set= map.entrySet();  //返回:key和value的封装

       for(Entry entry:set){

           System.out.println(entry.getKey()+":"+entry.getValue());

       }

    }

}