how to use an abstract class in java

1interface methods{
2    public void hey();
3    public void bye();
4}
5
6//unable to implement all the abstract methods in the interface so 
7// the other class automatically becomes abstract
8abstract class other implements methods{
9    public void hey(){
10        System.out.println("Hey");
11    }
12}
13
14//able to implement all the methods so is not abstract
15class scratch implements methods {
16    public void hey(){
17        System.out.println("Hey");
18    }
19    public void bye() {
20        System.out.println("Hey");
21    }
22}