java 遍历Map并且获取其中的键值

import java.util.Collection;

import java.util.HashMap;

import java.util.Iterator;

import java.util.Map;

import java.util.Set;

import java.util.TreeMap;

/**

* 遍历map集合中的键值的方法

* @Description TestMap

* @author Administrator

*/

public class TestMap {

public static void main(String[] args) {

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

// 要想有序的输出，用TreeMap

// Map<String,String> map = new TreeMap<String, String>();

map.put("1", "zhangsan");// 向集合中添加对象

map.put("2", "lisi");

map.put("3", "zhaoliu");

System.out.println("方法一");

// 获取Map集合的key的Set集合

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

Iterator<String> it = keySet.iterator();

while (it.hasNext()) {

String key = it.next();// 获取Key值对象

String value = map.get(key);// 获取键值对象

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

}

System.out.println("---------------------");

System.out.println("方法二");

// 获取Map集合的key,value集合Map.Entry<String, String>

Iterator<Map.Entry<String, String>> its = map.entrySet().iterator();

while(its.hasNext()){

Map.Entry<String, String> entryMap = its.next();

String key = entryMap.getKey();

String value = entryMap.getValue();

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

}

System.out.println("---------------------");

System.out.println("方法三");

// 获取Map集合的value集合

Collection coll = map.values();

for(Object obejct : coll){

String value = obejct.toString();// 获取键值对象

System.out.println(value);

}

}

}