面象对的umv 视图示例：

用户  银行  帐户  怎么关联

帐户代码：

文件命名 Account

 

package com.atuigu.exer4;import org.omg.CORBA.PUBLIC_MEMBER;public class Account {    private double balance;        public Account(double init_balance) {        this.balance = init_balance;           }        public double getBalance() {        return balance;    }    public void deposit(double amt) {        if(amt>0) {            balance +=amt;            System.out.println("存钱成功");        }            }        public void withdraw(double amt) {        if(balance>=amt) {            balance-=amt;            System.out.println("余额不足");        }    }//支        }//主函数结束

银行代码：文件命名：Customer

package com.atuigu.exer4;public class Customer {    private String firstName;    private String lastName;    private Account account;    public Customer(String f, String l) {        this.firstName = f;        this.lastName = l;            }    public String getFirstName() {        return firstName;    }    public void setFirstName(String firstName) {        this.firstName = firstName;    }    public String getLastName() {        return lastName;    }    public void setLastName(String lastName) {        this.lastName = lastName;    }    public Account getAccount() {        return account;    }    public void setAccount(Account account) {        this.account = account;    }    }

用户代码：文件命名：Bank

package com.atuigu.exer4;public class Bank {    private Customer[] customers;    //定义一个可以装很多用户的数组类;    private int  numberofCustomer;        public Bank() {        customers = new Customer[10];            }        public void addCustomer(String f,String l) {        Customer cust = new Customer(f,l);        customers[numberofCustomer] = cust;        numberofCustomer++;            }        public int getNumofCustomers(){        return numberofCustomer;            }        public Customer getCustomer(int index) {        if(index>=0 && index < numberofCustomer){        return customers[index];        }        return null;                    }                        }

主函数代码示例：文件命名：BankTest

package com.atuigu.exer4;public class BankTest {    public static void main(String[] args) {        Bank bank = new Bank();        bank.addCustomer("jane","Smith");        bank.addCustomer("ok", "err");                Account a = new Account(2000);                bank.getCustomer(0).setAccount(a);                bank.getCustomer(0).getAccount().withdraw(500);        double balance = bank.getCustomer(0).getAccount().getBalance();        System.out.print(""+bank.getCustomer(0).getFirstName());        System.out.println("奶奶的银业有我少个"+ bank.getNumofCustomers());                            }}