确定两个Java对象是否属于同一个类 [英] Determine if two Java objects are of the same class

问题描述

我试图做相当于

if ( object1.class == object2.class )
{
    //do something
}  

这当然不起作用，我用什么方法可以忽略？

which of course doesn't work, what method am I overlooking?

推荐答案

如果他们来自完全相同的类：

If they're from the exact same class:

boolean result = object1.getClass().equals( object2.getClass());

现在，如果它们是兼容的类（如果一个是另一个的后代类）：

Now if they are compatible classes (if one is of a descendent class to the other):

HashMap<String,Object> hashMap = new HashMap<String,Object>();
LinkedHashMap<String,Object> linkedHashMap = new LinkedHashMap<String,Object>();
boolean result = hashMap.getClass().isAssignableFrom( linkedHashMap.getClass() );

由于LinkedHashMap是HashMap的子类，因此结果变量为true，所以这对你来说可能更好，因为它会找到确切的和子类匹配。

As LinkedHashMap is a subclass of HashMap this result variable will be true, so this might probably be better for you as it's going to find exact and subclass matches.

另外，你应该避免在变量上使用.class，因为它可能不会给你正确的结果，例如：

Also, you should avoid using ".class" on variables, as it might not give you the correct result, example:

Object someText = "text value";
System.out.println( someText.class.getName() ); //this will print java.lang.Object and not java.lang.String

当你是使用.class你可以访问变量static属性而不是对象本身的类。

When you're using ".class" you're acessing the variable static property and not the class of the object itself.

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