状态模式

public interface State {
    void shouldDo(String s);
}

public class CloseState implements State {
    @Override
    public void shouldDo(String s) {
        System.out.println("关闭状态:" + s);
    }
}

public class OpenState implements State {
    @Override
    public void shouldDo(String s) {
        System.out.println("开放状态:" + s);
    }
}

public class AccordingStateDo {
    State state;

    public AccordingStateDo(State state) {
        this.state = state;
    }
    void defaultDo(String s){
        state.shouldDo(s);
    }
}

测试

public class Test {
    public static void main(String[] args) {
        AccordingStateDo accordingStateDo = new AccordingStateDo(new CloseState());
        accordingStateDo.defaultDo("停止");
        AccordingStateDo accordingStateDo1 = new AccordingStateDo(new OpenState());
        accordingStateDo1.defaultDo("继续");
    }
}