源码:
首先链接数据库 :创建包com.hp.util 在包里创建类DBHepler 在包里链接数据库
package com.hp.util; import java.sql.Connection; import java.sql.DriverManager; import java.sql.SQLException; public class DBHepler { public static Connection getConn() { Connection conn= null; try { Class.forName("com.mysql.jdbc.Driver"); String url="jdbc:mysql://localhost:3306/usmydb?serverTimezone=Asia/Shanghai"; conn= DriverManager.getConnection(url,"root","123456"); } catch (ClassNotFoundException | SQLException e) { e.printStackTrace(); } return conn; } //输出看一下是否链接 public static void main(String[] args) { System.out.println(getConn()); } }
运行效果:
输出这个则数据库链接成功
然后创建包com.hp.test 在包里创建类Test 在test里面实现各种方法
package com.hp.test; import com.hp.util.DBHepler; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.Scanner; public class Test { public void Meu(){ System.out.println("**************************"); System.out.println("*******欢迎来到银行********"); System.out.println("***1、用户新增***"); System.out.println("***2、修改用户***"); System.out.println("***3、存钱***"); System.out.println("***4、取钱***"); System.out.println("***5、退卡***"); System.out.println("**************************"); System.out.println("请选择您要的 *** 作内容:"); Scanner sc=new Scanner(System.in); String str=sc.next(); char c=str.charAt(0); switch (c){ case '1': add(); break; case '2': update(); break; case '3': deposit(); break; case '4': drawMonry(); break; case '5': withdraw(); break; } } //展示全部 public void showAll(){ Connection conn= DBHepler.getConn(); PreparedStatement ps=null; String sql="select * from bank"; try { ps=conn.prepareStatement(sql); ResultSet rs=ps.executeQuery(); while (rs.next()) { System.out.println("用户id:"+rs.getInt(1)+" "+"用户姓名:"+rs.getString(2)+" " +"用户密码:"+rs.getString(3)+" "+"用户余额"+rs.getDouble(4)+" "); } } catch (SQLException e) { e.printStackTrace(); }finally { try { conn.close(); ps.close(); } catch (SQLException e) { e.printStackTrace(); } } } //增加用户 public void add(){ System.out.println("********用户新增********"); Scanner sc=new Scanner(System.in); System.out.println("请输入添加用户账号"); String name=sc.next(); System.out.println("请输入添加用户密码"); String password=sc.next(); System.out.println("请输入添加用户余额"); double banlace=sc.nextDouble(); Connection conn=DBHepler.getConn(); String sql="insert into bank values(null,?,?,?)"; PreparedStatement ps=null; try { ps=conn.prepareStatement(sql); ps.setString(1, name); ps.setString(2, password); ps.setDouble(3, banlace); int i=ps.executeUpdate(); if (i>0){ System.out.println("添加成功"); Meu(); }else{ System.out.println("添加成功"); } } catch (SQLException e) { e.printStackTrace(); }finally { try { conn.close(); ps.close(); } catch (SQLException e) { e.printStackTrace(); } } } //修改用户 public void update(){ System.out.println("********用户修改********"); System.out.println("************修改用户信息**************"); Scanner sc= new Scanner(System.in); System.out.println("输入修改的用户id"); int id=sc.nextInt(); System.out.println("输入修改用户账号"); String name=sc.next(); System.out.println("输入修改用户密码"); String password=sc.next(); System.out.println("输入修改用户金额"); double banlance=sc.nextDouble(); Connection conn=DBHepler.getConn(); String sql="update bank set name=?,password=?,balance=? where id=?"; PreparedStatement ps=null; try { ps=conn.prepareStatement(sql); ps.setString(1, name); ps.setString(2, password); ps.setDouble(3, banlance); ps.setInt(4, id); int i=ps.executeUpdate(); if(i>0){ System.out.println("修改成功"); Meu(); }else { System.out.println("修改失败"); } } catch (SQLException e) { e.printStackTrace(); }finally { try { conn.close(); ps.close(); } catch (SQLException e) { e.printStackTrace(); } } } //用户存钱 public void deposit(){ System.out.println("*******用户存钱********"); Scanner sc=new Scanner(System.in); System.out.println("请输入存钱用户的姓名:"); String name=sc.next(); System.out.println("请输入存钱用户的密码:"); String password=sc.next(); System.out.println("请输入存钱用户的金额:"); double balance=sc.nextDouble(); Connection connn=DBHepler.getConn(); String sql="update bank set balance=balance+? where name=? and password=?"; PreparedStatement ps=null; try { ps= connn.prepareStatement(sql); ps.setDouble(1, balance); ps.setString(2, name); ps.setString(3, password); int i=ps.executeUpdate(); if (i>0) { System.out.println("存入成功,存入金额为:"+balance); Meu(); }else{ System.out.println("存入失败"); } } catch (SQLException e) { e.printStackTrace(); }finally { try { connn.close(); ps.close(); } catch (SQLException e) { e.printStackTrace(); } } } //用户取钱 public void drawMonry(){ System.out.println("*******用户取钱********"); Scanner sc=new Scanner(System.in); System.out.println("请输入取钱用户的姓名:"); String name=sc.next(); System.out.println("请输入取钱用户的密码:"); String password=sc.next(); System.out.println("请输入取钱用户的金额:"); double balance=sc.nextDouble(); Connection connn=DBHepler.getConn(); String sql="update bank set balance=balance-? where name=? and password=?"; PreparedStatement ps=null; try { ps= connn.prepareStatement(sql); ps.setDouble(1, balance); ps.setString(2, name); ps.setString(3, password); int i=ps.executeUpdate(); if (i>0) { System.out.println("取出成功,取出金额为:"+balance); Meu(); }else{ System.out.println("取出失败"); } } catch (SQLException e) { e.printStackTrace(); }finally { try { connn.close(); ps.close(); } catch (SQLException e) { e.printStackTrace(); } } } public void withdraw(){ System.out.println("退出成功,请收好您的卡"); System.exit(0); } }
最后创建包 com.hp.controller 在包里面创建测试类bank
package com.hp.controller; import com.hp.test.Test; public class Bank { public static void main(String[] args) { Test t=new Test(); t.Meu(); } }
最后运行效果:
欢迎分享,转载请注明来源:内存溢出
评论列表(0条)