Java简单登陆界面实现

Dear 丶 2022-04-01 05:56 282阅读 0赞

**利用Java连接MySQL做登陆界面**  
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_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：

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;

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3lhbmdfc2h1YWlf_size_16_color_FFFFFF_t_70]

我也是初学不久，分享一下！

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