java基础の解析 map

package com.csdn;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

public class MapTest {
	public static void main(String[] args) {
		List<UserName> list1 = new ArrayList<UserName>();
		for(int i=0;i<2;i++){
			UserName user = new UserName();
			user.setName("name"+(int)(Math.random()*100));
			user.setAge((int)(Math.random()*100));
			list1.add(user);
		}
		List<UserName> list2 = new ArrayList<UserName>();
		for(int i=0;i<2;i++){
			UserName user = new UserName();
			user.setName("name"+(int)(Math.random()*100));
			user.setAge((int)(Math.random()*100));
			list2.add(user);
		}
		Map<String,List<UserName>> map = new HashMap<String, List<UserName>>();
		map.put("key1",list1);
		map.put("key2",list2);
//		解析map ① 效率高
		Iterator<Map.Entry<String,List<UserName>>> it = map.entrySet().iterator();
		while(it.hasNext()){
			Map.Entry entry = it.next();
			System.out.println("key = "+entry.getKey());   
			List<UserName> lst1 = (ArrayList<UserName>)entry.getValue();
			for(UserName b:lst1){
				System.out.println("解析map ① = "+b.getName()+"  age = "+b.getAge());
			}
		}
		System.out.println("--------------------------------------------------------");
//		解析map ② 效率低
		Iterator<String> iterator = map.keySet().iterator();
		while(iterator.hasNext()){
			String key1 = iterator.next();
			System.out.println("******* key = "+ key1);
			List<UserName> lst1 = (ArrayList<UserName>)map.get(key1);
			for(UserName b:lst1){
				System.out.println("解析map ② name = "+b.getName()+"  age = "+b.getAge());
			}
		}
		System.out.println("--------------------------------------------------------");
//		解析map ③
		for(Object obj:map.keySet()){
			Object key3 = obj;
			System.out.println("key = " + key3);
			List<UserName> lst3 = (ArrayList<UserName>)map.get(obj);
			for(UserName bb:lst3){
				System.out.println("解析map ③.1 name = "+bb.getName()+"  age = "+bb.getAge());
			}
		}
		System.out.println("--------------------------------------------------------");
		for(Map.Entry entry:map.entrySet()){
			String key4 = entry.getKey().toString();
			System.out.println("key = "+key4);
			List<UserName> lst4 = (ArrayList<UserName>)entry.getValue();
			for(UserName b4:lst4){
				System.out.println("解析map ③.2 name = "+b4.getName()+"  age = "+b4.getAge());
			}
		}
		for(Iterator it5 = map.keySet().iterator();it5.hasNext();)
		{
			String key5 = (String)it5.next();
			System.out.println("key = "+key5);
			List<UserName> lst5 = (ArrayList<UserName>)map.get(key5);
			for(UserName b5:lst5){
				System.out.println("解析map ⑤.1 name = "+b5.getName()+"  age = "+b5.getAge());
			}
		}
		for(Iterator it6 = map.entrySet().iterator();it6.hasNext();){
			Map.Entry entry = (Map.Entry)it6.next();
			System.out.println(entry.getKey()+" "+entry.getValue());
		}
		System.out.println("--------------------------------------------------------");
	}
}