CODEWITHSUNDEEP
javaclasscomparison
Marshall Davis
Marshall Davis

Reputation: 3630

Determine if two Java objects are of the same class

I am attempting to do the equivalent of 

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

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

Upvotes: 60

Views: 67105

Answers (4)

Rich Adams
Rich Adams

Reputation: 26574

You're missing the getClass() method,

if (object1.getClass().equals(object2.getClass())) 
{ 
    // do something 
}

Upvotes: 16

Maurício Linhares
Maurício Linhares

Reputation: 40333

If they're from the exact same class:

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

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() );

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.

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

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

Upvotes: 92

Jetbeard
Jetbeard

Reputation: 343

You're looking for the getClass method, defined in java.lang.Class.

(Source: http://download.oracle.com/javase/7/docs/api/java/lang/Class.html)

Upvotes: 4

chubbsondubs
chubbsondubs

Reputation: 38696

object1.getClass() == object2.getClass()

Upvotes: 4

Related Questions