遍历map

package com;

import java.util.Collection;

import java.util.HashMap;

import java.util.Iterator;

import java.util.Map;

import java.util.Map.Entry;

import java.util.Set;

/**

 * 遍历Map

 * @author Administrator

 */

public class IterateMapKey {

public static void main(String[] args) {

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

//添加3个元素

map.put("k1", 1);

map.put("k2", 2);

map.put("k3", 3);

System.out.println("-----获取所有的key------");

Set<String> keys = map.keySet();

for( String key : keys ){

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

}

System.out.println("-----获取所有 key-value------");

//java.util.Map.Entry

Set<Entry<String,Integer> > entries = map.entrySet();

//获取用于遍历Set集合的迭代器

Iterator<Entry<String,Integer>> it = entries.iterator();

while(it.hasNext()){

//遍历每一组键值对

Entry<String,Integer> entry = it.next();

String key = entry.getKey();

int value = entry.getValue();

System.out.println(key+"="+value);

}

System.out.println("-----返回的所有value不是存入的Set集合------");

Collection<Integer> values = map.values();

for(Integer value : values){

System.out.println("value:"+value);

}

}

}