java网页登录
方法一:
采用JOptionPane中的一个非常有用的静态方法 showOptionPane();
源码如下:
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.JPasswordField;
import javax.swing.JOptionPane;
import javax.swing.BoxLayout;
import javax.swing.Box;
import javax.swing.BorderFactory;
public class Login1 {
    public static void main(String[] args) {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI(); 
            }
        });
    }
    static void createAndShowGUI() {
        JFrame mainFrame = new JFrame();
        mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        mainFrame.setBounds(250,250,400,300);        
        mainFrame.setVisible(false);
        usernameField = new JTextField(10);
        passwordField = new JPasswordField(10);      
        Object[] options = {"登录","取消"};
        int i = JOptionPane.showOptionDialog(null,createLoginPanel(),"登录信息",JOptionPane.DEFAULT_OPTION,JOptionPane.PLAIN_MESSAGE,null,options,options[0]);
        if(i==0) { 
            String username = usernameField.getText();
            String password = passwordField.getText();
            if(!username.equals("") && !password.equals("")) {
                mainFrame.getContentPane().add(new JLabel("用户名:"+username+"    密码是:"+password,JLabel.CENTER));
                mainFrame.show();
            }
            else {
                JOptionPane.showMessageDialog(null,"用户名和密码不能为空","提示",JOptionPane.WARNING_MESSAGE);
                System.exit(1);
            }
        }
        else System.exit(0);      
    }
    static JPanel createLoginPanel() {
        JPanel ret = new JPanel();        
             
        JPanel usernamePanel = new JPanel();
        usernamePanel.add(new JLabel("用户名:",JLabel.RIGHT));
        usernamePanel.add(usernameField);
        JPanel passwordPanel = new JPanel();
        passwordPanel.add(new JLabel("密  码:",JLabel.RIGHT));
        passwordPanel.add(passwordField);
        
        Box box = new Box(BoxLayout.Y_AXIS);
        box.add(usernamePanel); box.add(passwordPanel);
        ret.add(box);
         
        ret.setBorder(BorderFactory.createTitledBorder(BorderFactory.createLineBorder(new Color(244,144,44)),"填写登录信息"));      
        return ret;
    }
    static JFrame         mainFrame     = null;
    static JTextField     usernameField = null;
    static JPasswordField passwordField = null;
}
运行:
javac -deprecation Login1.java  
java Login
(因为有一个过期的API,所以用了 -deprecation 命令)
 
方法二,使用了两个JFrame类共同实现,第一次显示第一个frame,当点了登录后且操作合法时,第一个窗口就被释放了 dispose();再显示第二个窗口:
源码如下:
import java.awt.Color;
import java.awt.BorderLayout;
import java.awt.event.*;
import javax.swing.*;
public class Login2 {
    public static void main(String[] args) {
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
    static void createAndShowGUI() {
        //////////////////////////////////////////////////////////////
        loginWindow = new JFrame("登录信息");
        loginWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
        loginWindow.setBounds(350,350,250,200);
        loginWindow.setResizable(false);
        JPanel usernamePanel = new JPanel();
        usernamePanel.add(new JLabel("用户名:",JLabel.CENTER));
        usernamePanel.add(usernameField);
 
        JPanel passwordPanel = new JPanel();
        passwordPanel.add(new JLabel("密  码:",JLabel.CENTER));
        passwordPanel.add(passwordField);
        Box box = new Box(BoxLayout.Y_AXIS);
        box.add(usernamePanel);  box.add(passwordPanel);
        JPanel infoPanel = new JPanel();
        infoPanel.add(box);
        infoPanel.setBorder(BorderFactory.createTitledBorder(BorderFactory.createLineBorder(new Color(244,144,44)),"填写登录信息"));
        JButton submitButton = new JButton("登录");
        JButton cancelButton = new JButton("取消");
        submitButton.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e) {
                String username = usernameField.getText();
                String password = passwordField.getText();
             
                if(!username.equals("") && !password.equals("")) {
                    loginWindow.dispose();                
                    mainFrame.getContentPane().add(new JLabel("用户名:"+username+"    密码是:"+password,JLabel.CENTER));
                    mainFrame.setVisible(true);
                }
                else {
                    JOptionPane.showMessageDialog(null,"用户名和密码不能为空","提示",JOptionPane.WARNING_MESSAGE);
                    System.exit(1);
                }
            }
        });
        cancelButton.addActionListener(new ActionListener(){
            public void actionPerformed(ActionEvent e) {
                System.exit(0);
            }
        });
        JPanel buttonPanel = new JPanel();
        buttonPanel.add(submitButton); buttonPanel.add(cancelButton);
        loginWindow.getContentPane().add(infoPanel,BorderLayout.CENTER);
        loginWindow.getContentPane().add(buttonPanel,BorderLayout.SOUTH);
        loginWindow.getContentPane().add(new JPanel(),BorderLayout.EAST);
        loginWindow.getContentPane().add(new JPanel(),BorderLayout.WEST);
        loginWindow.setVisible(true);
        /////////////////////////////////////////////////////////////////
        mainFrame = new JFrame(); 
        mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        mainFrame.setBounds(250,250,400,300);
        mainFrame.setVisible(false);
    }
    static JFrame loginWindow,mainFrame;
    static final JTextField usernameField = new JTextField(10);
    static final JPasswordField passwordField = new JPasswordField(10);
}
运行:
javac -deprecation Login2.java
java Login2
㈡ java实现简单登录界面
自己写的比较规范的代码,都有注释:
import javax.swing.JFrame;//框架
import javax.swing.JPanel;//面板
import javax.swing.JButton;//按钮
import javax.swing.JLabel;//标签
import javax.swing.JTextField;//文本框
import java.awt.Font;//字体
import java.awt.Color;//颜色
import javax.swing.JPasswordField;//密码框
import java.awt.event.ActionListener;//事件监听
import java.awt.event.ActionEvent;//事件处理
import javax.swing.JOptionPane;//消息窗口
public class UserLogIn extends JFrame{
 public JPanel pnluser;
 public JLabel lbluserLogIn;
 public JLabel lbluserName;
 public JLabel lbluserPWD;
 public JTextField txtName;
 public JPasswordField pwdPwd;
 public JButton btnSub;
 public JButton btnReset;
 
 public UserLogIn(){
  pnluser = new JPanel();
  lbluserLogIn = new JLabel();
  lbluserName = new JLabel();
  lbluserPWD = new JLabel();
  txtName = new JTextField();
  pwdPwd = new JPasswordField();
  btnSub = new JButton();
  btnReset = new JButton();
  userInit();
 }
 
 public void userInit(){
  this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);//设置关闭框架的同时结束程序
  this.setSize(300,200);//设置框架大小为长300,宽200
  this.setResizable(false);//设置框架不可以改变大小
  this.setTitle("用户登录");//设置框架标题
  this.pnluser.setLayout(null);//设置面板布局管理
  this.pnluser.setBackground(Color.cyan);//设置面板背景颜色
  this.lbluserLogIn.setText("用户登录");//设置标签标题
  this.lbluserLogIn.setFont(new Font("宋体",Font.BOLD | Font.ITALIC,14));//设置标签字体
  this.lbluserLogIn.setForeground(Color.RED);//设置标签字体颜色
  this.lbluserName.setText("用户名:");
  this.lbluserPWD.setText("密    码:");
  this.btnSub.setText("登录");
  this.btnReset.setText("重置");
  this.lbluserLogIn.setBounds(120,15,60,20);//设置标签x坐标120,y坐标15,长60,宽20
  this.lbluserName.setBounds(50,55,60,20);
  this.lbluserPWD.setBounds(50,85,60,25);
  this.txtName.setBounds(110,55,120,20);
  this.pwdPwd.setBounds(110,85,120,20);
  this.btnSub.setBounds(85,120,60,20);
  this.btnSub.addActionListener(new ActionListener()//匿名类实现ActionListener接口
   {
    public void actionPerformed(ActionEvent e){
     btnsub_ActionEvent(e);
    }    
   }
  ); 
  this.btnReset.setBounds(155,120,60,20);
  this.btnReset.addActionListener(new ActionListener()//匿名类实现ActionListener接口
   {
    public void actionPerformed(ActionEvent e){
     btnreset_ActionEvent(e);
    }    
   }
  );   
  this.pnluser.add(lbluserLogIn);//加载标签到面板
  this.pnluser.add(lbluserName);
  this.pnluser.add(lbluserPWD);
  this.pnluser.add(txtName);
  this.pnluser.add(pwdPwd);
  this.pnluser.add(btnSub);
  this.pnluser.add(btnReset);
  this.add(pnluser);//加载面板到框架
  this.setVisible(true);//设置框架可显  
 }
 
 public void btnsub_ActionEvent(ActionEvent e){
  String name = txtName.getText();
  String pwd = String.valueOf(pwdPwd.getPassword());
  if(name.equals("")){
   JOptionPane.showMessageDialog(null,"账号不能为空","错误",JOptionPane.ERROR_MESSAGE);
   return;
  }else if (pwd.equals("")){
   JOptionPane.showMessageDialog(null,"密码不能为空","错误",JOptionPane.ERROR_MESSAGE);
   return;
  }else if(true){
   this.dispose();
  }else{
   JOptionPane.showMessageDialog(null,"账号或密码错误","错误",JOptionPane.ERROR_MESSAGE);
   return;
  }
 }
 
 public void btnreset_ActionEvent(ActionEvent e){
  txtName.setText("");
  pwdPwd.setText("");
 }
 
 public static void main(String[] args){
  new UserLogIn();
 }
}
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JButton_ JButton 绫荤殑瀹炰緥銆傜敤浜庡垱寤烘寜阍绫讳技瀹炰緥涓镄 "Login"銆
