hashMap遍历方式

package Ch17;

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

/**
 * Created by liwenj on 2017/7/28.
 */
public class MapTest1 {
    public static void main(String[] args) {
        HashMap<String,Dog> hashMap = new HashMap<>();
        Dog dog1 = new Dog("胡了", "泰迪");
        Dog dog2 = new Dog("美美", "泰迪");
        Dog dog3 = new Dog("佳佳", "泰迪");
        hashMap.put("胡了", dog1);
        hashMap.put("美美", dog2);
        hashMap.put("佳佳", dog3);
//        boolean set = hashMap.containsKey("莎莎");
//        if(set==false){
//            throw new InputMismatchException("没有这个名字的狗狗");
//        }
//        System.out.println(set);
        System.out.println("for循环增强遍历");
        Set<String> keys = hashMap.keySet();
        for (Object O : keys) {
            System.out.println(O + "\t" + hashMap.get(O));
        }
        System.out.println("迭代器遍历");
        Iterator<String> it = keys.iterator();
        while (it.hasNext()) {
            String key = (String) it.next();
            System.out.println(key + "\t" + hashMap.get(key));
        }
        System.out.println("entryset方式遍历");
        Set<Map.Entry<String, Dog>> entries = hashMap.entrySet();
        for(Map.Entry<String,Dog> entry:entries){
            System.out.println(entry.getKey()+"\t"+entry.getValue());
        }
    }
}