What happens when a class implements two interfaces and both have a method with same name and signature?

This is a valid scenario. If a type implements two interfaces, and each interface define a method that has identical signature, then in effect there is only one method, and they are not distinguishable.

The below snippet compiles and runs.

public interface InterfaceA {
	void method1();
}
public interface InterfaceB {
	void method1();
}
public class ClassImplementing2Interface implements InterfaceA,InterfaceB {

	@Override
	public void method1() {
	System.out.println("hello from method1");
		
	}
	
	public static void main(String[] args) {
		new ClassImplementing2Interface().method1();
	}
	
}

hello from method1

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