读书人

施用泛型迭代Map集合

发布时间: 2012-09-18 16:21:42 作者: rapoo

使用泛型迭代Map集合
package com.bird.beanutils;

import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Set;
import java.util.Map.Entry;

import org.junit.Test;

/**
* @use 使用泛型对Map进行迭代
* @author Bird
*
*/
public class DemoMap {

@Test
public void test1(){//对Map进行迭代
Map<Integer,String> map = new LinkedHashMap<Integer,String>();
map.put(1, "one");
map.put(2, "two");
map.put(3, "three");
map.put(4, "four");
map.put(5, "five");
map.put(7, "seven");

//传统EntrySet迭代
Set<Map.Entry<Integer, String>> set = map.entrySet();
Iterator<Entry<Integer, String>> it = set.iterator();
while(it.hasNext()){
Map.Entry<Integer, String> entry = it.next();
int key = entry.getKey();
String value = entry.getValue();

System.out.println("key" + " "+ key + "\n"+"value" + " "+ value);
}
}


@Test
public void test2(){//使用增强for循环
Map<Integer,String> map = new LinkedHashMap<Integer,String>();
map.put(1, "one");
map.put(2, "two");
map.put(3, "three");
map.put(4, "four");
map.put(5, "five");
map.put(7, "seven");

for(Map.Entry<Integer, String> en : map.entrySet()){
int num = en.getKey();
String value = en.getValue();

System.out.println(num + "==" + value);
}

}
}

读书人网 >编程

热点推荐