JavaにおけるMapの4つの遍歴方式

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

public class MapDemo {

	public static void main(String[] args) {

		Map<Integer,String> map=new HashMap<Integer,String>();
		
		map.put(1,"Java    ");
		map.put(2,"         ");
		map.put(3,"     ，      ");
		map.put(4,"    Java     ");
		map.put(5,"    ");
		map.put(6,"    ");
		
		//   ：      
		for(Integer key:map.keySet()){
			
			System.out.println("key="+key+",value="+map.get(key));
		}
		
		System.out.println("===============================================");
		
		//   ：           
		Iterator<Map.Entry<Integer,String>> it=map.entrySet().iterator();
		
		while(it.hasNext()){
			
			Map.Entry<Integer,String> entry=it.next();
			
			System.out.println("key="+entry.getKey()+",value="+entry.getValue());
		}
		
		System.out.println("===============================================");
		
		//   ：  ，       
		for(Map.Entry<Integer,String> entry:map.entrySet()){
			
			System.out.println("key="+entry.getKey()+",value="+entry.getValue());
		}
		
		System.out.println("===============================================");
		
		//   ：    values
		for(String value:map.values()){
			
			System.out.println("value="+value);
		}
	}

}