状态模式在软件设计中的应用与实现

public interface State {/*** &＃64;desc 预订房间* &＃64;return void*/public void bookRoom();/*** &＃64;desc 退订房间* &＃64;return void*/public void unsubscribeRoom();/*** &＃64;desc 入住* &＃64;return void*/public void checkInRoom();/*** &＃64;desc 退房* &＃64;return void*/public void checkOutRoom();}

public class Room {/** 房间的三个状态*/State freeTimeState; //空闲状态State checkInState; //入住状态State bookedState; //预订状态State state ;public Room(){freeTimeState &＃61; new FreeTimeState(this);checkInState &＃61; new CheckInState(this);bookedState &＃61; new BookedState(this);state &＃61; freeTimeState ; //初始状态为空闲}/*** &＃64;desc 预订房间* &＃64;return void*/public void bookRoom(){state.bookRoom();}/*** &＃64;desc 退订房间* &＃64;return void*/public void unsubscribeRoom(){state.unsubscribeRoom();}/*** &＃64;desc 入住* &＃64;return void*/public void checkInRoom(){state.checkInRoom();}/*** &＃64;desc 退房* &＃64;return void*/public void checkOutRoom(){state.checkOutRoom();}public String toString(){return "该房间的状态是:"&＃43;getState().getClass().getName();}/** getter和setter方法*/public State getFreeTimeState() {return freeTimeState;}public void setFreeTimeState(State freeTimeState) {this.freeTimeState &＃61; freeTimeState;}public State getCheckInState() {return checkInState;}public void setCheckInState(State checkInState) {this.checkInState &＃61; checkInState;}public State getBookedState() {return bookedState;}public void setBookedState(State bookedState) {this.bookedState &＃61; bookedState;}public State getState() {return state;}public void setState(State state) {this.state &＃61; state;}}

/*** &＃64;project: design_state* &＃64;author chenssy* &＃64;date 2013-8-24* &＃64;Description: 空闲状态只能预订和入住*/
public class FreeTimeState implements State {Room hotelManagement;public FreeTimeState(Room hotelManagement){this.hotelManagement &＃61; hotelManagement;}public void bookRoom() {System.out.println("您已经成功预订了...");hotelManagement.setState(hotelManagement.getBookedState()); //状态变成已经预订}public void checkInRoom() {System.out.println("您已经成功入住了...");hotelManagement.setState(hotelManagement.getCheckInState()); //状态变成已经入住}public void checkOutRoom() {//不需要做操作}public void unsubscribeRoom() {//不需要做操作}}

/*** &＃64;project: design_state* &＃64;author chenssy* &＃64;date 2013-8-24* &＃64;Description: 入住状态房间只能退房*/
public class BookedState implements State {Room hotelManagement;public BookedState(Room hotelManagement) {this.hotelManagement &＃61; hotelManagement;}public void bookRoom() {System.out.println("该房间已近给预定了...");}public void checkInRoom() {System.out.println("入住成功...");hotelManagement.setState(hotelManagement.getCheckInState()); //状态变成入住}public void checkOutRoom() {//不需要做操作}public void unsubscribeRoom() {System.out.println("退订成功,欢迎下次光临...");hotelManagement.setState(hotelManagement.getFreeTimeState()); //变成空闲状态}}

/*** &＃64;project: design_state* &＃64;author chenssy* &＃64;date 2013-8-24* &＃64;Description: 入住可以退房*/
public class CheckInState implements State {Room hotelManagement;public CheckInState(Room hotelManagement) {this.hotelManagement &＃61; hotelManagement;}public void bookRoom() {System.out.println("该房间已经入住了...");}public void checkInRoom() {System.out.println("该房间已经入住了...");}public void checkOutRoom() {System.out.println("退房成功....");hotelManagement.setState(hotelManagement.getFreeTimeState()); //状态变成空闲}public void unsubscribeRoom() {//不需要做操作}}

public class Test {public static void main(String[] args) {//有3间房Room[] rooms &＃61; new Room[2];//初始化for(int i &＃61; 0 ; i