Abstract class can have one abstract method at miminum.
All methods in Interface should be abstract, so user has to implement all methods when he implements an interace.
here is my example
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//test.java
class test
{
public static void main(String args[])
{
human Peter = new human();
Peter.playingRPG();
}
}
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//human.java
class human extends hominoidea implements playingComputer
{
void eating()
{
System.out.println("Use spoon or chopstick to eat"

;
}
public void icq()
{
System.out.println("start icq"

;
System.out.println("Find who is online"

;
System.out.println("chat with your friend"

;
}
public void playingRPG()
{
System.out.println("start the game"

;
System.out.println("Load a save"

;
System.out.println("go to a town"

;
}
}
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//playingComputer.java
public interface playingComputer
{
public abstract void icq(); // abstract can be omitted here because method is supposed to be abstract in interface
public void playingRPG();
}
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//hominoidea.java
abstract class hominoidea
{
void walkWithFourLeg()
{
System.out.println("walking"

;
}
abstract void eating();
}
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