Sample.java

package com.example;

public class Sample extends SampleAbstruct<String> {
	public static void main(String[] args) {
		System.out.println(new Sample().test(" Bob!!"));
	}

	@Override
	public String test(String name) {
		return hello + name;
	}
}

SampleAbstruct.java

package com.example;

public abstract class SampleAbstruct<E> implements SampleInterface<E> {

	protected final String hello = "hello";
}

SampleInterface.java

package com.example;

public interface SampleInterface<E> {

	public E test(E e);
}