Can you do method overloading with generics and only change the generic type of the method signature?

Question

If you don't use Java Generics, I believe it's not possible to have two methods in the same class that differ only in their return type.

In other words, this would be illegal:

public HappyEmotion foo(T emotion) {
    // do something
}   

public SadEmotion foo(T emotion) {
    // do something else
}   

Is the same true when overloading methods that return a generic type that may implement different interfaces, such as if the following two methods were present in the same class definition:

public <T extends Happy> T foo(T emotion) {
    // do something
}   

public <T extends Sad> T foo(T emotion) {
    // do something else
}   

Would this be illegal?

Answer 1

This is legal since the input parameter too differs based on the type..

For this reason, following is legal,

public <T extends Happy> T foo(T emotion) {
    // do something
}   

public <T extends Sad> T foo(T emotion) {
    // do something else
}

But following is not,

public <T extends Happy> String foo(T emotion) {
    // do something
}   

public <T extends Happy> T foo(T emotion) {
    // do something else
} 

Thanks...