Java Map 반복(Iteration) 시키는 방법

package com.tistory.jononeworld;
 
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
 
public class MapIterationSample {
    
    public static void main(String[] args) {
        Map<String, Object> map = new HashMap<String, Object>();
 
        map.put("키1", "값1");
        map.put("키2", "값2");
        map.put("키3", "값3");
        map.put("키4", "값4");
        map.put("키5", "값5");
        map.put("키6", "값6");
 
        //방법1
        Iterator<String> keys = map.keySet().iterator();
        while( keys.hasNext() ){
            String key = keys.next();
            System.out.println( String.format("키: %s, 값: %s", key, map.get(key)) );
        }
 
        //방법2
        for( Map.Entry<String, Object> elem : map.entrySet() ){
            System.out.println( String.format("키: %s, 값: %s", elem.getKey(), elem.getValue()) );
        }
 
        //방법3
        for( String key: mep.keySet() ){
            System.out.println( String.format("키: %s, 값: %s", key, map.get(key)) );