利用Java连接MySQL做登陆界面，供大家参考，具体内容如下
1、首先需要建立一个类，在这里，我命名为newLogin
newLogin类的代码如下
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package p4;import java.awt.Dimension;import java.awt.Font;import java.awt.Toolkit;import java.awt.event.ActionEvent;import java.awt.event.ActionListener;import java.sql.Connection;import java.sql.ResultSet;import java.sql.SQLException;import java.sql.Statement;import javax.swing.ButtonGroup;import javax.swing.JButton;import javax.swing.JFrame;import javax.swing.JLabel;import javax.swing.JOptionPane;import javax.swing.JPasswordField;import javax.swing.JRadioButton;import javax.swing.JTextField;public class newLogin extends JFrame implements ActionListener{ private static final long serialVersionUID = 1L; private Connection con = null; private Statement statement = null; private ResultSet res = null; private ButtonGroup buttongroup = new ButtonGroup(); private MyPanel jp = new MyPanel(); private JLabel ul = new JLabel("用户名："); private JLabel pl = new JLabel("密 码："); private JLabel ts = new JLabel(""); private JTextField uname = new JTextField(); private JPasswordField pword = new JPasswordField(); private JRadioButton[] butArray = { new JRadioButton("学生",true), new JRadioButton("教师") }; private JButton login = new JButton("登陆"); private JButton reset = new JButton("重置"); public newLogin() { addListener(); initialFrame(); } private void initialFrame() { Font font = new Font("宋体",Font.BOLD,12); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setTitle("登陆"); jp.setLayout(null); ul.setBounds(100, 30, 60, 30); jp.add(ul); uname.setBounds(170, 30, 140, 30); jp.add(uname); pl.setBounds(100, 80, 60, 30); pword.setBounds(170, 80, 140, 30); jp.add(pl); jp.add(pword); ts.setBounds(100, 160, 200, 50); jp.add(ts); ts.setFont(font); login.setBounds(100, 220, 70, 30); jp.add(login); login.setFont(font); reset.setBounds(220, 220, 70, 30); jp.add(reset); reset.setFont(font); add(jp); setResizable(false); buttongroup.add(butArray[0]); buttongroup.add(butArray[1]); butArray[0].setBounds(120, 130, 100, 50); jp.add(butArray[0]); butArray[1].setBounds(220, 130, 100, 50); jp.add(butArray[1]); butArray[0].setContentAreaFilled(false); butArray[1].setContentAreaFilled(false); Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize(); int centerX = screenSize.width/2; int centerY = screenSize.height/2; int w = 427; int h = 331; setBounds(centerX-w/2, centerY-h/2, w, h); setVisible(true); uname.requestFocus(true); getContentPane().add(jp); jp.getRootPane().setDefaultButton(login); } private void addListener() { this.login.addActionListener(this); this.uname.addActionListener(this); this.pword.addActionListener(this); } @Override public void actionPerformed(ActionEvent e) { if(e.getSource() == uname) { pword.requestFocus(); } if(e.getSource() == pword) { butArray[0].requestFocus(); } if(e.getSource() == butArray[0]||e.getSource() == butArray[1]||e.getSource() == login) {// this.ts.setText("正在为您努力加载，请稍等......"); int type = this.butArray[0].isSelected()?0:1; String username = this.uname.getText().trim(); char[] p = this.pword.getPassword(); String password = String.valueOf(p).trim(); if(username.equals("")) { JOptionPane.showMessageDialog(this, "请输入用户名！","错误",JOptionPane.ERROR_MESSAGE); ts.setText(""); return ; } if(password.equals("")) { JOptionPane.showMessageDialog(this, "请输入密码！","错误",JOptionPane.ERROR_MESSAGE); ts.setText(""); return ; } try { con = new connection().getConnection(); //调用自己写的一个数据库连接类 statement = con.createStatement(); if(type == 0) { String sql = "select * from stuuser where "+ "username_stu='"+username+"'and password_stu='"+password+"'"; res = statement.executeQuery(sql); if(res.next()) { JOptionPane.showMessageDialog(this, "登录成功！","提示",JOptionPane.INFORMATION_MESSAGE); this.dispose(); } else { JOptionPane.showMessageDialog(this, "用户名或密码错误！","错误",JOptionPane.ERROR_MESSAGE); ts.setText(""); uname.setText(""); pword.setText(""); } //关闭数据库连接 if(res != null) { res.close(); } if(statement != null) { statement.close(); } if(con != null) { con.close(); } } else { String sql = "select * from teauser where "+ "username_tea='"+username+"'and password_tea='"+password+"'"; res = statement.executeQuery(sql); if(res.next()) { String spec_name = res.getString(1); JOptionPane.showMessageDialog(this, "登录成功！","提示",JOptionPane.INFORMATION_MESSAGE); this.dispose(); } else { JOptionPane.showMessageDialog(this, "用户名或密码错误！","错误",JOptionPane.ERROR_MESSAGE); ts.setText(""); uname.setText(""); pword.setText(""); } //关闭数据库连接 if(res != null) { res.close(); } if(statement != null) { statement.close(); } if(con != null) { con.close(); } } }catch(SQLException ea) { ea.printStackTrace(); } } else if(e.getSource() == reset) { uname.setText(""); pword.setText(""); } }} |
2、编写数据库连接类，在这里命名为connection,然后在类里写一个获取连接的放回，并返回一个连接。
connection类的代码如下：
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package p4;import java.sql.Connection;import java.sql.DriverManager;//import java.sql.ResultSet;import java.sql.SQLException;//import java.sql.Statement;public class connection { private Connection con = null;// private Statement statement = null;// private ResultSet res = null; String driver = "com.mysql.cj.jdbc.Driver"; String url = "jdbc:mysql://localhost:3306/Stu_manager?serverTimezone=Asia/Shanghai"; String name = "root"; String passwd = "123456"; public connection() { } public Connection getConnection() { try{ Class.forName(driver).newInstance(); con = DriverManager.getConnection(url,name,passwd); }catch(ClassNotFoundException e){ System.out.println("对不起，找不到这个Driver"); e.printStackTrace(); }catch(SQLException e){ e.printStackTrace(); }catch(Exception e){ e.printStackTrace(); } return con; }} |
3、在MySQL数据库中需建立两个用户表，分别用来存储不同用户的登陆账号和密码，这里学生用户表为stuuser,教师用户表为teauser,建表的SQL语句如下:
stuuser表：
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create table stuuser( username_stu varchar(20) primary key, password_stu char(20) not null,)ENGINE=InnoDB DEFAULT CHARSET=utf8; |
teauser表：
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create table teauser( username_tea varchar(20) primary key, password_tea char(20) not null,)ENGINE=InnoDB DEFAULT CHARSET=utf8; |
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持服务器之家。
原文链接：https://blog.csdn.net/yang_shuai_/article/details/85338669
