实验 22：状态模式
实验 22：状态模式
本次实验属于模仿型实验，通过本次实验学生将掌握以下内容：
1、理解状态模式的动机，掌握该模式的结构；
2、能够利用状态模式解决实际问题。
[实验任务一]：银行账户
用Java代码模拟实现课堂上的“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。
实验要求：
1. 提交源代码；
JAVA
package rjsj.no22;
public class GreenState extends AccountState{
public GreenState(double balance,Account acc) {
this.balance = balance;
this.account = acc;
this.stateName = "正常状态";
}
}
package rjsj.no22;
public class RedState extends AccountState{
public RedState(AccountState state) {
this.balance = state.balance;
this.account = state.account;
this.stateName="透支状态";
}
public void withdraw(double amount) {
System.out.println(account.getOwner()+"取款"+amount);
System.out.println("抱歉，您的账户已处于透支状态，不能取款！");
}
}
package rjsj.no22;
public class YellowState extends AccountState{
public YellowState(AccountState state) {
this.balance = state.balance;
this.account = state.account;
this.stateName="欠费状态";
}
}
package rjsj.no22;
public class Account {
private AccountState state;
private String owner;
public AccountState getState() {
return state;
}
public void setState(AccountState state) {
this.state = state;
}
public String getOwner() {
return owner;
}
public void deposit(double amount) {
state.deposit(amount);
}
public void withdraw(double amount) {
state.withdraw(amount);
}
public Account(String owner, double initBalance) {
this.owner = owner;
this.state = new GreenState(initBalance,this);
System.out.println(this.owner + "开户成功！银行卡初始金额：" + initBalance);
System.out.println("----------------------------------------------------");
}
}
package rjsj.no22;
public abstract class AccountState {
protected Account account;//账户名
protected double balance;//账户金额
protected String stateName;//当前状态
public void deposit(double amount) {
System.out.println(account.getOwner() + "存款" + amount);
this.balance = this.balance + amount;
stateCheck();
System.out.println("账户余额：" + this.balance);
System.out.println("账户状态：" + account.getState().stateName);
}
public void withdraw(double amount) {
System.out.println(account.getOwner() + "取款" + amount);
this.balance = this.balance - amount;
stateCheck();
System.out.println("账户余额：" + this.balance);
System.out.println("账户状态：" + account.getState().stateName);
}
public void stateCheck(){//状态审查
if( balance >= -1000 && balance < 0 ) {
account.setState(new YellowState(this));
}else if( balance < -1000 ) {
account.setState(new RedState(this));
}else if ( balance > 0 ){
account.setState(new GreenState(this.balance,this.account));
}
}
}
package rjsj.no22;
public class Client {
public static void main(String[] args) {
Account account = new Account("张三",100);
account.deposit(8888);
System.out.println("------------------------------");
account.withdraw(666);
System.out.println("------------------------------");
account.deposit(50);
System.out.println("------------------------------");
account.withdraw(9000);
System.out.println("------------------------------");
account.withdraw(50000);
System.out.println("------------------------------");
account.deposit(3000);
System.out.println("------------------------------");
account.withdraw(100);
}
}
C++
#include<iostream>
using namespace std;
class Account;
class AccountState{
public:
Account *acc;
double balance;
string stateName;
public:
virtual void stateCheck()=0;
void deposit(double amount);
virtual void withdraw(double amount);
};
class Account{
private:
AccountState *state;
string owner;
public:
Account(string owner,double init);
void setState(AccountState *state) {
this->state=state;
}
AccountState* getState() {
return this->state;
}
string getOwner() {
return this->owner;
}
void deposit(double amount) {
state->deposit(amount);
}
void withdraw(double amount) {
state->withdraw(amount);
}
};
class RedState :public AccountState{
public:
RedState(AccountState *state) {
this->balance = state->balance;
this->acc = state->acc;
this->stateName="透支状态";
}
void withdraw(double amount){cout<<"账户处于透支状态，不能取款！"<<endl;}
void stateCheck();
};
class YellowState :public AccountState{
public:
YellowState(AccountState *state) {
this->balance = state->balance;
this->acc = state->acc;
this->stateName="欠费状态";
}
void stateCheck();
};
class GreenState:public AccountState{
public:
GreenState(double balance,Account *acc) {
this->balance = balance;
this->acc = acc;
this->stateName="正常状态";
}
GreenState(AccountState *state) {
this->acc=state->acc;
this->balance=state->balance;
this->stateName="正常状态";
}
void stateCheck() {
if(balance>=-1000&&balance<0) {
acc->setState(new YellowState(this));
}else if(balance<-1000) {
acc->setState(new RedState(this));
}
else{
acc->setState(new GreenState(this));
}
}
};
void RedState::stateCheck(){
if(balance>=-1000&&balance<0) {
acc->setState(new YellowState(this));
}else if(balance<-1000) {
acc->setState(new RedState(this));
}
else {
acc->setState(new GreenState(this));
}
}
void YellowState::stateCheck() {
if(balance>=-1000&&balance<0) {
acc->setState(new YellowState(this));
}else if(balance<-1000) {
acc->setState(new RedState(this));
}
else{
acc->setState(new GreenState(this));
}
}
void AccountState::deposit(double amount){
cout<<acc->getOwner()<<"存款"<<amount<<endl;
this->balance+=amount;
stateCheck();
cout<<"账户余额："<<this->balance<<endl;
cout<<"账户状态："<<acc->getState()->stateName<<endl;
}
void AccountState::withdraw(double amount){
cout<<acc->getOwner()<<"取款"<<amount<<endl;
this->balance-=amount;
stateCheck();
cout<<"账户余额："<<this->balance<<endl;
cout<<"账户状态："<<acc->getState()->stateName<<endl;
}
Account::Account(string owner,double init){
this->owner=owner;
this->state=new GreenState(init,this);
cout<<"恭喜"<<this->owner<<"开户成功！银行卡初始金额："<<init<<endl;
cout<<"--------------------------------------------------"<<endl;
}
int main(){
Account *account=new Account("张三",100);
account->deposit(100);
cout<<"--------------------------------------------------"<<endl;
account->withdraw(1000);
cout<<"--------------------------------------------------"<<endl;
account->deposit(1000);
cout<<"--------------------------------------------------"<<endl;
account->withdraw(2000);
cout<<"--------------------------------------------------"<<endl;
account->withdraw(10000);
cout<<"--------------------------------------------------"<<endl;
account->withdraw(1);
cout<<"--------------------------------------------------"<<endl;
account->deposit(100000);
cout<<"--------------------------------------------------"<<endl;
return 0;
}
运行结果：
