一个类中维护两个map对象，出现了奇怪的问题，不知是不是SDK本身就有问题？大家进来看看？

Question

...
你放入两个map的是同一个对象的引用，改变了对象，当然都会反映出来变化。

Answer 1

Map map=new HashMap();
if(map.containsKey("123")){
System.out.println("122");
}else{
System.out.println("000");
}

 
Map todayCustomerMap = new HashMap();
HashMap todayCustomerActionMap=new HashMap();
Collections.synchronizedMap(todayCustomerMap) ;
Collections.synchronizedMap(todayCustomerActionMap) ;

Dog dog=new Dog();
dog.setAge(12);
dog.setName("xiaoluo");

Dog dog1=new Dog();
dog1.setAge(15);
dog1.setName("xiaoluo1");
Dog dog2=new Dog();//新的对象
BeanUtils.copyProperties(dog,dog2);
Dog dog3=new Dog();//新的对象
BeanUtils.copyProperties(dog1,dog3);
todayCustomerMap.put("xiaoluo", dog2);
todayCustomerMap.put("xiaoluo1", dog3);

todayCustomerActionMap.put("xiaoluo", dog);
todayCustomerActionMap.put("xiaoluo1", dog1);
//这里从map中取出来，并作了修改
Dog dog03=(Dog)todayCustomerActionMap.get("xiaoluo");
//Dog dog03=new Dog();
dog03.setAge(12);
dog03.setName("aaa");
todayCustomerActionMap.put("xiaoluo", dog03);


Dog dog04=(Dog)todayCustomerActionMap.get("xiaoluo");//注意这个对象作了修改
Dog dog05=(Dog)todayCustomerMap.get("xiaoluo");//注意这个对象没有作任何修改
//这里发生了奇怪的事，dog05为什么也修改了？我不知道为什么？
System.out.println(dog04.getAge()+dog04.getName());
System.out.println(dog05.getAge()+dog05.getName());
if(dog04.equals(dog05)){//判断两个对象值是否相等
System.out.println("equal");
}else{
System.out.println("not equal");
}