Return types and multiple inheritance?

Question

interface i1{
    int test();
}

interface i2{
    String test();
}

class Test implements i1,i2{
    <Return type> test(){
         //code here
    }
}

If return type of implemented method is int , error says Return type is incompatible with i2.test() If return type of implemented method is String , error says Return type is incompatible with i1.test()

How should I implement those two interfaces in my class Test

Any Help appreciable.

Answer 1

You can't. They're incompatible. Only the method name and arguments are considered in this case.

Your choices are:

1. Change the name of one of the methods
2. Make the argument lists different contain different types

Answer 2

How should I implement those two interfaces in my class Test

Either implement them in two different classes, or rename (or change the parameter signature) one of the interface methods.

Answer 3

It is not possible to solve this by only filling in some appropriate return type.

You'll have to find an alternative solution; for example rename the test method in one of the interfaces.

Answer 4

This will never works you must have to find an alternative.ie Rename the methods or u can provide the inner class implementation as following

class Test {


 static i1 i=new i1() {

    @Override
    public int test() {

        return 0;
    }
};

        static i2 i22=new i2() {

    @Override
    public String test() {

        return "String";
    }
};


public static void main(String...strings ){

    if(someObject instanceof String){

        i.test();



    } else {

        i22.test();
    }



}



}