user
public class User { private String name; private String password; public String getName() { return name; } public void setName(String name) { this.name = name; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public User() { super(); } public User(String name, String password) { super(); this.name = name; this.password = password; } @Override public String toString() { return "User [name=" + name + ", password=" + password + "]"; } }utils
public class DBUtils { private static String driverClass; private static String url; private static String user; private static String password; static{ //加载配置文件 ResourceBundle rb=ResourceBundle.getBundle("info"); //info src下配 +置文件 在同一文件夹下 driverClass = rb.getString("driverClass"); url = rb.getString("url"); user=rb.getString("user"); password=rb.getString("password"); try { Class.forName(driverClass); } catch (ClassNotFoundException e) { e.printStackTrace(); } } //获取连接 Connection 导包 java.sql.Connection public static Connection getConnection() throws SQLException{ return DriverManager.getConnection(url,user,password); } //释放资源 public static void closeAll(ResultSet rs,Statement stmt,Connection conn){ if(rs!=null){ try { rs.close(); } catch (SQLException e) { e.printStackTrace(); } rs=null; } if(stmt!=null){ try { stmt.close(); } catch (SQLException e) { e.printStackTrace(); } stmt=null; } if(conn!=null){ try { conn.close(); } catch (SQLException e) { e.printStackTrace(); } stmt=null; } } }curd测试
public class TestCurd { public static void main(String[] args){ Scanner sc=new Scanner(System.in); TestCurd tc = new TestCurd(); System.out.println("请输入：1.查询,2.添加,3.修改,4.删除"); while(true){ int in=sc.nextInt(); switch(in){ case 1 : System.out.println("查询全部数据"); tc.testSelevt(); continue; case 2 : System.out.println("请输入要添加的姓名 密码"); String s1=sc.next(); String [] arr=s1.split(","); User u=new User(arr[0],arr[1]); tc.testInsert(u); continue; case 3 : System.out.println("请输入要修改的姓名和修改后的密码"); String s2=sc.next(); //按姓名修改 String[] arr1 = s2.split(","); User u1=new User(arr1[0],arr1[1]); tc.testUpdate(u1); continue; case 4: System.out.println("输入要删除的姓名"); String s3=sc.next(); User u2=new User(); u2.setName(s3); tc.testDelete(u2); continue; default : System.out.println("输入有误"); } } } public void testSelevt() { //加载驱动 获取连接 Connection conn = null; //获取预编译sql的执行对象 PreparedStatement ps = null; //执行sql语句 ResultSet rs = null; try { conn = DBUtils.getConnection(); String sql="select*from user"; /*System.out.println(sql);*/ ps = conn.prepareStatement(sql); rs = ps.executeQuery(); while(rs.next()){ System.out.print(rs.getString("name")); System.out.print(rs.getString("password")); System.out.println(); } } catch (SQLException e) { e.printStackTrace(); }finally{ DBUtils.closeAll(rs, ps, conn); } } //update 增 添加 public void testInsert(User u) { Connection conn = null; //获取执行sql语句对象 PreparedStatement ps = null; try { conn = DBUtils.getConnection(); ps = conn.prepareStatement("INSERT INTO USER (NAME,PASSWORD)VALUES(?,?)"); ps.setString(1, u.getName()); ps.setString(2,u.getPassword()); //执行sql语句 result int result = ps.executeUpdate(); if(result>0){ System.out.println("添加成功"+result); }else{ System.out.println("失败"); } } catch (SQLException e) { e.printStackTrace(); }finally { //关闭资源 DBUtils.closeAll(null,ps,conn); } } //修改 public void testUpdate(User u) { Connection conn=null; PreparedStatement ps=null; try { conn=DBUtils.getConnection(); String sql="update user set password=? where name=?"; ps=conn.prepareStatement(sql); ps.setString(1,u.getPassword()); ps.setString(2, u.getName()); int jieguo = ps.executeUpdate(); if(jieguo>0){ System.out.println("修改成功"+jieguo); }else{ System.out.println("修好失败"); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); }finally{ DBUtils.closeAll(null, ps, conn); } } public void testDelete(User u) { Connection conn = null; PreparedStatement ps = null; try { conn = DBUtils.getConnection(); String sql="delete from User where name=?"; ps = conn.prepareStatement(sql); ps.setString(1, u.getName()); int result = ps.executeUpdate(); if(result>0){ System.out.println("删除成功"); }else{ System.out.println("删除失败"); } } catch (SQLException e) { // TODO Auto-generated catch block e.printStackTrace(); } DBUtils.closeAll(null, ps, conn); } }