Behavioral -- State

--- State.java ---

package behavioral.state;

public interface State {

void sampleOperation();

}

--- ConcreteState.java ---

package behavioral.state;

public class ConcreteState implements State {

public void sampleOperation() {

}

}

--- Context.java ---

package behavioral.state;

public class Context {

private State state;

public void sampleOperation() {
state.sampleOperation();
}

public void setState(State state) {
this.state = state;
}

}