Map.entry类

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package Map;

import java.util.HashMap;

import java.util.Iterator;

import java.util.Set;

import java.util.Map.Entry;

public class Map {

    /**

     * @param args

     */

    public static void main(String[] args) {

        //先设置好一个map

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

        map.put("1","1");

        map.put("2","2");

        map.put("3","3");

        map.put("4","4");

        map.put("5","5");

        //使用keySet()从一个map中得到所有的信息

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

        if(keys!=null)

            //得到迭代器

            {

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

                while(it.hasNext())

                {

                String key=it.next();

                String value=map.get(key).toString();

                System.out.println(value);

                }

            }

        //使用entrySet()从一个map中得到所有信息

        Set<Entry<String,Object>> s=map.entrySet();

        if(s!=null){

            Iterator<Entry<String,Object>> ite=s.iterator();

            while(ite.hasNext()){

                Entry<String,Object> en=ite.next();

                String key=en.getKey();

                String value=en.getValue().toString();

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

            }

        }

    }

}