java连接mysql（2）

来源：互联网发布：算法与并行计算编辑：程序博客网时间：2024/06/05 02:51

极其简单的注册，登录

数据库表设计
user表

package com.wangchong.login;import java.awt.FlowLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.sql.Connection;import java.sql.DriverManager;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JOptionPane;import javax.swing.JTextField;/** * 实现登录功能 *  * @author ASUS *  */public class Login {    private final static JFrame login_frame = new JFrame("登录");    private final static JLabel login_label1 = new JLabel("账号：(最多16位)");    private final static JLabel login_label2 = new JLabel("密码：(最多16位)");    private final static JTextField login_text1 = new JTextField(16);    private final static JTextField login_text2 = new JTextField(16);    private final static JButton login_b1 = new JButton("登录");    private final static JButton login_b2 = new JButton("注册");    public static void main(String[] args) {        /*         * 注册按钮点击事件         */        login_b2.addActionListener(new ActionListener() {            @Override            public void actionPerformed(ActionEvent e) {                // TODO Auto-generated method stub                new Register();            }        });        /*         * 登录按钮点击事件         */        login_b1.addActionListener(new ActionListener() {            @Override            public void actionPerformed(ActionEvent e) {                // TODO Auto-generated method stub                try {                    select_sql();                } catch (SQLException e1) {                    // TODO Auto-generated catch block                    e1.printStackTrace();                } catch (ClassNotFoundException e1) {                    // TODO Auto-generated catch block                    e1.printStackTrace();                }            }        });        login_frame.setSize(350, 150);        login_frame.setLayout(new FlowLayout(FlowLayout.LEFT, 2, 2));        login_frame.setLocationRelativeTo(null);        // login_frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        login_frame.add(login_label1);        login_frame.add(login_text1);        login_frame.add(login_label2);        login_frame.add(login_text2);        login_frame.add(login_b1);        login_frame.add(login_b2);        login_frame.setVisible(true);    }    /*     * 连接数据库，并实现登录验证     *      * @throws SQLException     *      * @throws ClassNotFoundException     */    public static void select_sql() throws SQLException, ClassNotFoundException {        // 加载mysql驱动        Class.forName("com.mysql.jdbc.Driver");        System.out.println("driver loaded");        // 建立一个连接        Connection connection = DriverManager.getConnection(                "jdbc:mysql://localhost/test", "root", "xxxxxxxx");        System.out.println("database connection");        // 建立一个statement        Statement statement = connection.createStatement();        // 获取username        String username = login_text1.getText();        // 获取password        String password = login_text2.getText();        // 定义一个sql查询语句        String select_sql = "select password from user where username=" + "\""                + username + "\"";        System.out.println(select_sql);        // 执行sql查询语句        ResultSet rs = statement.executeQuery(select_sql);        if (rs.next()) {            if (rs.getString(1).equals(password)) {                JOptionPane.showMessageDialog(null, "登录成功！", "登录成功",                        JOptionPane.INFORMATION_MESSAGE);            } else {                JOptionPane.showMessageDialog(null, "密码错误！", "密码错误",                        JOptionPane.ERROR_MESSAGE);            }        } else {            JOptionPane.showMessageDialog(null, "账号错误！", "账号错误",                    JOptionPane.ERROR_MESSAGE);        }    }}

package com.wangchong.login;import java.awt.FlowLayout;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.sql.Connection;import java.sql.DriverManager;import java.sql.SQLException;import java.sql.Statement;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JOptionPane;import javax.swing.JTextField;import com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException;/** * 实现注册功能 *  * @author ASUS *  */public class Register {    private final JFrame register_frame = new JFrame("注册");    private final JLabel register_label1 = new JLabel("账号：(最多16位)");    private final JLabel register_label2 = new JLabel("密码：(最多16位)");    private final JTextField register_text1 = new JTextField(16);    private final JTextField register_text2 = new JTextField(16);    // JButton register_b1 = new JButton("登录");    private final JButton register_b2 = new JButton("注册");    private String username;    private String password;    /*     * 构造函数     */    public Register() {        /*         * 注册按钮的点击事件         */        register_b2.addActionListener(new ActionListener() {            @Override            public void actionPerformed(ActionEvent e) {                // TODO Auto-generated method stub                try {                    insert_sql();                    register_frame.dispose();                } catch (SQLException e1) {                    // TODO Auto-generated catch block                    e1.printStackTrace();                } catch (ClassNotFoundException e1) {                    // TODO Auto-generated catch block                    e1.printStackTrace();                }            }        });        register_frame.setSize(350, 150);        register_frame.setLayout(new FlowLayout(FlowLayout.LEFT, 3, 2));        register_frame.setLocationRelativeTo(null);        // register_frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        register_frame.add(register_label1);        register_frame.add(register_text1);        register_frame.add(register_label2);        register_frame.add(register_text2);        register_frame.add(register_b2);        register_frame.setVisible(true);    }    /*     * 连接数据库，并将新用户添加到数据库中     *      * @throws SQLException     *      * @throws ClassNotFoundException     */    public void insert_sql() throws SQLException, ClassNotFoundException {        // 获取输入的用户名        username = register_text1.getText();        System.out.println(username);        // 获取输入的密码        password = register_text2.getText();        // 判断用户名是否合理        if (username.trim().equals("") || username.equals("null")                || username.length() > 16) {            JOptionPane.showMessageDialog(null, "用户名违规！", "错误提示",                    JOptionPane.ERROR_MESSAGE);        } else if (password.trim().equals("") || password.equals("null")                || password.length() > 16) {            JOptionPane.showMessageDialog(null, "密码违规！", "错误提示",                    JOptionPane.ERROR_MESSAGE);        } else {            // 加载mysql驱动            Class.forName("com.mysql.jdbc.Driver");            System.out.println("driver loaded");            // 建立一个连接            Connection connection = DriverManager.getConnection(                    "jdbc:mysql://localhost/test", "root", "xxxxxxxx");            System.out.println("database connected");            // 建立一个statement            Statement statement = connection.createStatement();            // 定义插入语句            String insert_sql = "insert into user (username,password)values(\'"                    + username + "\',\'" + password + "\')";            System.out.println(insert_sql);            // 执行sql语句            try {                int rs = statement.executeUpdate(insert_sql);                System.out.println("insert successfully");            } catch (MySQLIntegrityConstraintViolationException e) {                // TODO: handle exception                // System.out.println("用户名重复，请换一个");                JOptionPane.showMessageDialog(null, "用户名已被占用！", "错误提示",                        JOptionPane.ERROR_MESSAGE);            }            JOptionPane.showMessageDialog(null, "注册成功！", "注册成功",                    JOptionPane.INFORMATION_MESSAGE);            // 断开连接            connection.close();        }    }}

还是要加强一下对布局管理器的了解啊

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