今日总结

状态模式——java实现

 

问题描述：

模拟实现课堂上的“银行账户”的实例，要求编写客户端测试代码模拟用户存款和取款，注意账户对象状态和行为的变化。

Java源代码：

 

  1 //Account.java
  2 package shiyan22;
  3 /**
  4  * @Description：环境类
  5  * @author 张紫诺
  6  *
  7  */
  8 public class Account {
  9     private AccountState state;
 10     private String name;
 11     public Account(String name){
 12         this.name=name;
 13         state=new Greenstate(this);
 14         System.out.println(name+"开户成功！初始金额：0元");
 15         System.out.println("******************************");
 16     }
 17     public void setState(AccountState state){
 18         this.state=state;
 19     }
 20     public AccountState getState() {
 21         return this.state;
 22     }
 23     
 24     public String getName() {
 25         return name;
 26     }
 27     public void setName(String name) {
 28         this.name = name;
 29     }
 30     public void deposit(double money){
 31         state.deposit(money);
 32     }
 33     public void withdraw(double money){
 34         state.withdraw(money);
 35     }
 36 }
 37 //AccountState.java
 38 package shiyan22;
 39 /**
 40  * @Description：抽象状态类
 41  * @author 张紫诺
 42  *
 43  */
 44 public abstract class AccountState {
 45     protected Account acc;
 46     protected double balance;
 47     protected String stateName;
 48     public abstract void stateCheck(double balance);
 49     public double getBalance() {
 50         return balance;
 51     }
 52     public void setBalance(double balance) {
 53         this.balance = balance;
 54     }
 55     public String getStateName() {
 56         return stateName;
 57     }
 58     public void setStateName(String stateName) {
 59         this.stateName = stateName;
 60     }
 61     public void deposit(double amount) {
 62         System.out.println(acc.getName()+"存款"+amount+"元");
 63         balance+=amount;
 64         stateCheck(balance);
 65         System.out.println("当前余额："+balance+"元，当前状态："+acc.getState().stateName);
 66     }
 67     public void withdraw(double amount) {
 68         System.out.println(acc.getName()+"取款"+amount+"元");
 69         balance-=amount;
 70         stateCheck(balance);
 71         System.out.println("当前余额："+balance+"元，当前状态："+acc.getState().stateName);
 72     }
 73 } 
 74 //Greenstate.java
 75 package shiyan22;
 76 /**
 77  * @Description：正常状态类
 78  * @author 张紫诺
 79  *
 80  */
 81 public class Greenstate extends AccountState{
 82     public Greenstate(AccountState state){
 83         this.acc=state.acc;
 84         this.balance=state.balance;
 85         this.stateName="正常状态";
 86     }
 87     public Greenstate(Account acc){
 88         this.balance=0;
 89         this.acc=acc;
 90         this.stateName="正常状态";
 91     }
 92     public void stateCheck(double balance){
 93         if(balance<-1000){ 
 94             acc.setState(new Redstate(this));
 95         }else if(balance>=-1000&&balance<0){
 96             acc.setState(new Yellowstate(this));
 97         }
 98     }
 99 }
100 //Redstate.java
101 package shiyan22;
102 /**
103  * @Description：透支状态类
104  * @author 张紫诺
105  *
106  */
107 public class Redstate extends AccountState {
108 
109     public Redstate(AccountState state) {
110         this.acc=state.acc;
111         this.balance=state.getBalance();
112         this.stateName="透支状态";
113     }
114 
115     public void stateCheck(double balance) {
116         if(balance >= -1000 && balance < 0){
117             acc.setState(new Yellowstate(this));
118         }else if(balance >= 0){
119             acc.setState(new Greenstate(this));
120         }
121     }
122     public void withdraw(double amount) {
123             System.out.println("对不起，"+acc.getName()+",您不能取款");
124             System.out.println("当前余额："+balance+"元，当前状态："+acc.getState().stateName);
125     }
126 }
127 //Yellowstate.java
128 package shiyan22;
129 /**
130  * @Description：欠费状态类
131  * @author 张紫诺
132  *
133  */
134 public class Yellowstate extends AccountState {
135 
136     public Yellowstate(AccountState state) {
137         this.acc=state.acc;
138         this.balance=state.getBalance();
139         this.stateName="欠费状态";
140     }
141 
142     public void stateCheck(double balance) {
143         if(balance >=0 ){
144             acc.setState(new Greenstate(this));
145         }else if(balance < -1000){
146             acc.setState(new Redstate(this));
147         }
148     }
149 }
150 //Client.java
151 package shiyan22;
152 public class Client {
153     public static void main(String args[]){
154         Account acc=new Account("张三");
155         acc.deposit(2000);
156         System.out.println("---------------------------------------");
157         acc.withdraw(500);
158         System.out.println("---------------------------------------");
159         acc.withdraw(2000);
160         System.out.println("---------------------------------------");
161         acc.withdraw(600);
162         System.out.println("---------------------------------------");
163         acc.withdraw(200);
164     }
165 }