千鋒逆戰班，jdbc和mysql銀行案例

學習java第42天
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mysql代碼

創建數據庫 Account

• 創建一張表 t_ccount。有以下列
  • cardId：字符串，主鍵
  • password：字符串，非空
  • username：字符串，非空
  • balance：小數，非空
  • phone：字符串，非空

CREATE DATABASE Account CHARACTER SET utf8;
USE Account
CREATE TABLE t_account(
	cardid VARCHAR(20) PRIMARY KEY,
	`password` VARCHAR(20) NOT NULL,
	username VARCHAR(20) NOT NULL,
	balance DOUBLE NOT NULL,
	phone VARCHAR(11) NOT NULL

)CHARSET=utf8;

INSERT INTO t_account VALUES('b101','123','大慶',1000,'132444')
INSERT INTO t_account VALUES('b102','123','大白',6000,'132455')
INSERT INTO t_account VALUES('b103','123','大A',7000,'132466')
INSERT INTO t_account VALUES('b104','123','大B',8000,'132477')


SELECT * FROM t_account;

創建AccountSystem類，完成下列功能

• 開戶：控制檯輸入所有的賬戶信息，使用PreparedStatement添加至t_account表
• 存款：控制檯輸入卡號、密碼、存儲金額進行修改
• 取款：輸入卡號、密碼、取款金額
• 轉賬：輸入卡號、密碼、對方卡號、轉賬金額進行修改
• 修改密碼：控制檯輸入卡號、密碼，再輸入新密碼進行修改
• 註銷：控制檯輸入卡號、密碼，刪除對應的賬戶信息

AccountSystem代碼

package com.qf.day2.t3;

import java.sql.*;
import java.util.Scanner;

/*
- 開戶：控制檯輸入所有的賬戶信息，使用PreparedStatement添加至t_account表
- 存款：控制檯輸入卡號、密碼、存儲金額進行修改
- 取款：輸入卡號、密碼、取款金額
- 轉賬：輸入卡號、密碼、對方卡號、轉賬金額進行修改
- 修改密碼：控制檯輸入卡號、密碼，再輸入新密碼進行修改
- 註銷：控制檯輸入卡號、密碼，刪除對應的賬戶信息
try-catch 快速按鍵-- ctrl + alt + t
代碼格式化  ctrl + alt + l
快速定位異常處，  F2
提醒解決方案  alt+ enter
 */
public class AccountSystem {
    Scanner sc = new Scanner(System.in);
    PreparedStatement pre = null;
    private static Connection conn = null;
    ResultSet re = null;

    static {
        try {
            Class.forName("com.mysql.jdbc.Driver");
            conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/account?useUnicode=true&characterEncoding=utf8","root","740056981");

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
    //開戶
    public void refiter(){
        System.out.println("請輸入卡號");
        String cid = sc.next();
        System.out.println("請輸入密碼：");
        String password = sc.next();
        System.out.println("請輸入用戶名:");
        String username = sc.next();
        System.out.println("請輸入存款金額：");
        double balance = sc.nextDouble();
        System.out.println("請輸入手機號：");
        String phone = sc.next();

        try {
            String sql = "insert into t_account(cardid,password,username,balance,phone) values (?,?,?,?,?)";
            pre = conn.prepareStatement(sql);
            pre.setString(1,cid);
            pre.setString(2,password);
            pre.setString(3,username);
            pre.setDouble(4,balance);
            pre.setString(5,phone);
            int re = pre.executeUpdate();
            if(re>0){
                System.out.println("開戶成功");
            }else{
                System.out.println("開戶失敗");
            }

        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            try {
                if(pre !=null){
                    pre.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }


    }

    //存款
    public void saveMoney(){
        System.out.println("請輸入卡號：");
        String cid = sc.next();
        System.out.println("請輸入密碼：");
        String password = sc.next();
        System.out.println("請輸入存款金額：");
        double balance = sc.nextDouble();
        if (balance > 0) {

            try {
                String sql = "update t_account set balance = balance+? where cardid=? and password = ?";
                pre = conn.prepareStatement(sql);
                pre.setDouble(1,balance);
                pre.setString(2,cid);
                pre.setString(3,password);
                int i = pre.executeUpdate();
                if(i>0){
                    System.out.println("存款成功");
                }else{
                    System.out.println("存款失敗");
                }

            } catch (SQLException e) {
                e.printStackTrace();
            } finally {
                try {
                    if(pre != null){
                        pre.close();
                    }
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }
        } else {
            System.out.println("輸入存款金額錯誤，重新輸入");
        }

    }

    //取款
    public void takeMoney(){
        System.out.println("請輸入卡號：");
        String cid = sc.next();
        System.out.println("請輸入密碼：");
        String password = sc.next();
        System.out.println("請輸入取款金額：");
        double balance = sc.nextDouble();

        if (balance > 0) {
            try {
                String sql1= "select balance from t_account where cardid = ? and password = ?";
                pre = conn.prepareStatement(sql1);
                pre.setString(1,cid);
                pre.setString(2,password);

                re = pre.executeQuery();
                if(re.next()) {
                    double money = re.getDouble("balance");
                    if (balance <= money) {
                        String sql2 = "update t_account set balance = balance-? where cardid=? and password = ?";
                        pre = conn.prepareStatement(sql2);
                        pre.setDouble(1, balance);
                        pre.setString(2, cid);
                        pre.setString(3, password);
                        int i = pre.executeUpdate();
                        if (i > 0) {
                            System.out.println("取款成功");
                        }
                    }else{
                        System.out.println("餘額不足");
                    }
                }else{
                    System.out.println("輸入的用戶名或密碼錯誤");
                }

            } catch (SQLException e) {
                e.printStackTrace();
            }finally {
                try {
                    if(re != null){
                        re.close();
                    }
                    if(pre != null){
                        pre.close();
                    }
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }

        } else {
            System.out.println("輸入存款金額錯誤，重新輸入");
        }

    }
    //轉賬
    public void tranSefer(){
        System.out.println("請輸入自字的卡號：");
        String cid = sc.next();
        System.out.println("請輸入密碼：");
        String password = sc.next();
        System.out.println("請輸入轉賬的卡號：");
        String cid2 = sc.next();
        System.out.println("請輸入轉賬金額：");
        double money = sc.nextDouble();
        if(money > 0){
            try {
                String sql1 = "select balance from t_account where cardid=? and password = ?";
                pre = conn.prepareStatement(sql1);
                pre.setString(1,cid);
                pre.setString(2,password);
                re = pre.executeQuery();
                if(re.next()){
                    double money1 = re.getDouble("balance");//獲取自己賬號裏的餘額
                    if(money <= money1){//判斷轉賬金額是否小於餘額
                        try {
                            conn.setAutoCommit(false);
                            String sql2 = "update t_account set balance = balance-? where cardid = ? and password =?";
                            pre = conn.prepareStatement(sql2);
                            pre.setDouble(1,money);
                            pre.setString(2,cid);
                            pre.setString(3,password);
                            int i = pre.executeUpdate();

                            String sql3 = "update t_account set balance = balance + ? where cardid = ?";
                            pre = conn.prepareStatement(sql3);

                            pre.setDouble(1,money);
                            pre.setString(2,cid2);
                            int i1 = pre.executeUpdate();
                            if(i>0 && i1>0){

                                conn.commit();
                                System.out.println("轉賬成功");
                            }else{
                                conn.rollback();
                                System.out.println("轉賬失敗");
                            }
                        } catch (Exception e) {
                            conn.rollback();
                            System.out.println("轉賬失敗");
                            e.printStackTrace();
                        }


                    }else{
                        System.out.println("餘額不足");
                    }
                }else{
                    System.out.println("賬號或密碼錯誤");
                }
            } catch (Exception e) {
                e.printStackTrace();
            }finally {
                try {
                    if(re!=null){
                        re.close();
                    }
                    if(pre!=null){
                        pre.close();
                    }
                } catch (SQLException e) {
                    e.printStackTrace();
                }
            }


        }else {
            System.out.println("轉賬金額錯誤");
        }


    }

    //修改密碼
    public void setPas(){
        System.out.println("請輸入卡號：");
        String cid = sc.next();
        System.out.println("請輸入密碼：");
        String password = sc.next();
        System.out.println("請輸入新密碼：");
        String newpas = sc.next();

        try {
            String sql = "update t_account set password=? where cardid = ? and password = ?";
            pre = conn.prepareStatement(sql);
            pre.setString(1,newpas);
            pre.setString(2,cid);
            pre.setString(3,password);
            int i = pre.executeUpdate();
            if(i>0){
                System.out.println("修改成功");
            }else{
                System.out.println("修改失敗");
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }finally{
            try {
                if(pre != null){
                    pre.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }

        }

    }

    //註銷
    public void logOff(){
        System.out.println("請輸入卡號：");
        String cid = sc.next();
        System.out.println("請輸入密碼：");
        String password = sc.next();

        try {
            String sql = "delete from t_account where cardid = ? and password = ?";
            pre = conn.prepareStatement(sql);
            pre.setString(1,cid);
            pre.setString(2,password);
            int i = pre.executeUpdate();
            if(i>0){
                System.out.println("註銷成功");
            }else{
                System.out.println("註銷失敗");
            }

        } catch (SQLException e) {
            e.printStackTrace();
        } finally {
            try {
                if(pre != null){
                    pre.close();
                }
            } catch (SQLException e) {
                e.printStackTrace();
            }
        }
    }
    //退出
    public void exit(){
        try {
            if(conn != null){
                conn.close();
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }
}

TestAccount代碼

package com.qf.day2.t3;

import java.sql.SQLOutput;
import java.util.Scanner;

public class TestAccount {
    public static void main(String[] args) {
        AccountSystem as = new AccountSystem();
        Scanner sc = new Scanner(System.in);
        System.out.println("歡迎來到英雄聯盟銀行系統");
        int choice = 0;
        do{
            System.out.println("1、開戶 2、存款 3、取款 4、轉賬 5、修改密碼 6、註銷 0、退出");
            System.out.println("請選擇");
            choice = sc.nextInt();
            switch (choice){
                case 1:
                    as.refiter();
                    break;
                case 2:
                    as.saveMoney();
                    break;
                case 3:
                    as.takeMoney();
                    break;
                case 4:
                    as.tranSefer();
                    break;
                case 5:
                    as.setPas();
                    break;
                case 6:
                    as.logOff();
                    break;
                case 0:
                    as.exit();
                    return;
            }

        }while (choice !=0);

    }
}