Interface in java

[syruss kumar]

HI all,

I have created 2 interfaces with same method signature and implemented that in a class like below

Interface a{

public void test();
}

Interface b{

public void test();
}


class PlayJava implements a,b{
@override
public void test(){

}


1.why its implemented only one method its even throwing any compilation error or runtime error?
2.How JVM handle this.

thanks in advance



}

[Madhan Sundararajan Devaki]

1. This will not result in compilation error as JVM considers each a valid Java entity.

2. Java will execute the method implemented in the PlayJava class.

[syruss kumar]

Thanks devaki,

Yes it will not throw any compilation exception.It will work perfectly but how JVM handles these kind of scenarios that im really confusing .

Please can you clarify me.

Thanks in advance

[Vijay Tidake]

Hi,

What compiler sees that if you are implementing the interfaces then you have to override all the methods defined in it.
so your class follows that contract.
There in no ambiguity for the compiler in calling the method.

But if you take the case defined below

interface a {
	public void test();

	int value = 2;
}

interface b {
	public void test();

	int value = 1;
}

class PlayJava implements a, b {
	@Override
	public void test() {
		System.out.println(value);// line1
	}
}

at line 1 there is an error from compiler which says "The field value is ambiguous"
so you you want to access a particular constant you have to access it line <interface>.<variable>

Thanks