Java实现简单登陆界面

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

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：

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_managerserverTimezone=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：

create table stuuser(
 username_stu varchar(20) primary key,
 password_stu char(20) not null,
)ENGINE=InnoDB DEFAULT CHARSET=utf8;

teauser表：

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源码搜藏网。