标准的HashMap遍历

package littlejava;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
public class PhotoNum
{
    public static void main(String [] args)
    {
        HashMap> wrod=new HashMap>();
        HashMapdogMap=new HashMap();
        dogMap.put("dog1", new Dog(1,"dog1"));
        dogMap.put("dog2", new Dog(2,"dog2"));
        dogMap.put("dog3", new Dog(3,"dog3"));
        dogMap.put("dog4", new Dog(1,"dog4"));


        ////而entryset只要遍历一次，他把key和value都放到了entry中，所以就快了。
        Iterator iter = dogMap.entrySet().iterator();
        while (iter.hasNext()) {
            Map.Entry entry = (Map.Entry) iter.next();
            String key = (String) entry.getKey();
            Dog val = (Dog) entry.getValue();
            System.out.println("key: "+key + " val: "+val.getDogName() );
        }

    }
}


class Dog
{
    private int id;
    private String dogName;
    public Dog() {
        super();
    }
    public Dog(int id, String dogName) {
        super();
        this.id = id;
        this.dogName = dogName;
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getDogName() {
        return dogName;
    }
    public void setDogName(String dogName) {
        this.dogName = dogName;
    }


}