State Pattern

Java

by techbard 2016. 7. 19. 21:46

# IState.java

public interface IState {
IState s1();
IState s2();
IState s3();
}

# S1.java

public class S1 implements IState {

@Override
public IState s1() {
System.out.println("같은 S1 상태 반복");
return this;
}

@Override
public IState s2() {
System.out.println("A 이벤트 발생");
return new S2();
}

@Override
public IState s3() {
System.out.println("E 이벤트 발생");
return new S3();
}
}

# S2.java

public class S2 implements IState {

@Override
public IState s1() {
System.out.println("C 이벤트 발생");
return new S1();
}

@Override
public IState s2() {
System.out.println("같은 S2 상태 반복");
return this;
}

@Override
public IState s3() {
System.out.println("B 이벤트 발생");
return new S3();
}
}

# S3.java

public class S3 implements IState {

@Override
public IState s1() {
System.out.println("가능하지 않은 상태 전이");
return this;
}

@Override
public IState s2() {
System.out.println("D 이벤트 발생");
return new S2();
}

@Override
public IState s3() {
System.out.println("같은 S3 상태 반복");
return this;
}
}

public class StateManager {
private IState state;

public StateManager(IState state) {
this.state = state;
}

public void s1() {
this.state = state.s1();
}

public void s2() {
this.state = state.s2();
}

public void s3() {
this.state = state.s3();
}
}

# Main.java

public class Main {

public static void main(String[] args) {
StateManager sm = new StateManager(new S1());
sm.s2();
sm.s3();
sm.s2();
sm.s1();
sm.s3();
}
}