《大话设计模式》Java代码示例（十二）之状态模式

状态模式（State）：当一个对象的内在状态改变时允许改变其行为，这个对象看起来像是改变了其类。

package state;

/**
 * 状态模式(State)
 * 抽象状态
 */
public abstract class State {

    public abstract void coding(Work work);

}

package state;

/**
 * 状态模式(State)
 * 上午工作状态
 */
public class ForenoonState extends State {

    @Override
    public void coding(Work work) {
        if (work.getHour() < 12) {
            System.out.println("当前时间：" + work.getHour() + "点 上午工作，精神百倍！");
        } else {
            work.setState(new NoonState());
            work.coding();
        }
    }

}

package state;

/**
 * 状态模式(State)
 * 中午工作状态
 */
public class NoonState extends State {

    @Override
    public void coding(Work work) {
        if (work.getHour() < 13) {
            System.out.println("当前时间：" + work.getHour() + "点 饿了，午饭；犯困，午休！");
        } else {
            work.setState(new AfternoonState());
            work.coding();
        }
    }

}

package state;

/**
 * 状态模式(State)
 * 下午工作状态
 */
public class AfternoonState extends State {

    @Override
    public void coding(Work work) {
        if (work.isFinish()) {
            work.setState(new RestState());
            work.coding();
        } else {
            if (work.getHour() < 17) {
                System.out.println("当前时间：" + work.getHour() + "点 下午状态还不错，继续努力！");
            } else {
                work.setState(new EveningState());
                work.coding();
            }
        }
    }

}

package state;

/**
 * 状态模式(State)
 * 晚间工作状态
 */
public class EveningState extends State {

    @Override
    public void coding(Work work) {
        if (work.isFinish()) {
            work.setState(new RestState());
            work.coding();
        } else {
            if (work.getHour() < 21) {
                System.out.println("当前时间：" + work.getHour() + "点 加班哦，疲累之极！");
            } else {
                work.setState(new SleepingState());
                work.coding();
            }
        }
    }

}

package state;

/**
 * 状态模式(State)
 * 睡眠状态
 */
public class SleepingState extends State {

    @Override
    public void coding(Work work) {
        System.out.println("当前时间：" + work.getHour() + "点 不行了，睡着了！");
    }

}

package state;

/**
 * 状态模式(State)
 * 下班休息状态
 */
public class RestState extends State {

    @Override
    public void coding(Work work) {
        System.out.println("当前时间：" + work.getHour() + "点 下班回家了！");
    }

}

package state;

/**
 * 状态模式(State)
 * 工作类
 */
public class Work {

    private int hour;

    private State current;

    private boolean finish = false;

    public Work() {
        current = new ForenoonState();
    }

    public int getHour() {
        return hour;
    }

    public void setHour(int hour) {
        this.hour = hour;
    }

    public boolean isFinish() {
        return finish;
    }

    public void setFinish(boolean finish) {
        this.finish = finish;
    }

    public State getState() {
        return current;
    }

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

    public void coding() {
        current.coding(this);
    }

}

package state;

/**
 * 状态模式(State)
 * 客户端main方法
 */
public class Client {

    public static void main(String[] args) {
        Work work = new Work();
        work.setHour(9);
        work.coding();
        work.setHour(10);
        work.coding();
        work.setHour(12);
        work.coding();
        work.setHour(13);
        work.coding();
        work.setHour(14);
        work.coding();
        work.setHour(17);
        work.coding();
//        work.setFinish(true);
        work.setHour(19);
        work.coding();
        work.setHour(22);
        work.coding();
    }

}