【行为型模式】状态模式（state）之23种java设计模式

State接口类

public interface State {
void handle();
}

BookedState类

/**
 * 已预订状态
 * @author Administrator
 *
 */
public class BookedState implements State {
@Override
public void handle() {
System.out.println("房间已预订！别人不能定！");
}

}

CheckedInState类

/**
 * 已入住状态
 * @author Administrator
 *
 */
public class CheckedInState implements State {

@Override
public void handle() {
System.out.println("房间已入住！请勿打扰！");
}

}

FreeState类

/**
 * 空闲状态
 * @author Administrator
 *
 */
public class FreeState implements State {

@Override
public void handle() {
System.out.println("房间空闲！！！没人住！");
}
}

HomeContext类

/**
 * 房间对象
 * @author Administrator
 *
 */
public class HomeContext {
//如果是银行系统，这个Context类就是账号。根据金额不同，切换不同的状态！

private State state;

public void setState(State s){
System.out.println("修改状态！");
state = s;
state.handle();
}

}

Client测试类

public class Client {
public static void main(String[] args) {
HomeContext ctx = new HomeContext();

ctx.setState(new FreeState());
ctx.setState(new BookedState());

}
}