map 通过迭代器 遍历

package com.test;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
public class MapIterator {
    public static void main(String[] args){
        Map<String,String> map = new HashMap<String,String>();
        map.put("key1","value1");
        map.put("key2","value2");
        Set<String> keySet = map.keySet();
        Iterator<String> it = keySet.iterator();
        while (it.hasNext()){
            System.out.print(" "+it.next());
        }
        System.out.println();
        Iterator<Map.Entry<String,String>> itEntry = map.entrySet().iterator();
        while(itEntry.hasNext()){
            Map.Entry<String,String> entry = itEntry.next();
            System.out.print(" key: "+entry.getKey()+" value: "+entry.getValue());
        }
    }
}