Java_map

package Test;

import java.util.HashMap;
import java.util.Map;

public class MapTest {
    public static void main(String[]args){
        Map map1=new HashMap();
        Map map2=new HashMap();
        map1.put("1","aaa1");
        map1.put("1","bbb2");
        map2.put("10","aaaa10");
        map2.put("11","bbbb11");
        
        System.out.println("map1.get("1")="+map1.get("1"));
        System.out.println("map1.remove("1")="+map1.remove("1"));
        map1.putAll(map2);
        map2.clear();
        System.out.println("map1 IsEmpty?="+map1.isEmpty());
        System.out.println("map2 IsEmpty?="+map2.isEmpty());
        System.out.println("map中的键值对数size"+map1.size());
        System.out.println("KeySet="+map1.keySet());
        System.out.println("value="+map1.values());
        System.out.println("entrySet="+map1.entrySet());
        System.out.println("map1是否包含键:11="+map1.containsKey("11"));
        System.out.println("map1是否包含值:aaa1="+map1.containsValue("aaa1"));
    }
    
}

package Test;

import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.TreeMap;

public class MapSortExample {
    public static void main(String[]args){
        Map map1=new HashMap();
        Map map2=new LinkedHashMap();
        for(int i=0;i<10;i++){
            double s=Math.random()*100;
            map1.put(new Integer((int) s),"第 "+i+"个放入的元素:"+s+"
");
            map2.put(new Integer((int) s),"第 "+i+"个放入的元素:"+s+"
");
        }
            
        
        System.out.println("未排序前HashMap:"+map1);
        System.out.println("未排序前LinkedHashMap:"+map2);
        Map sortedMap=new TreeMap(map1);
        System.out.println("排序后:"+sortedMap);
        System.out.println("排序前:"+new TreeMap(map2));
    }

}