【实例简介】一个很基础的Java实例，实现最基础的增删改查

【实例截图】

账号：01101  密码：1234

【核心代码】

package com.sqc.view;

import java.awt.BorderLayout;

import java.awt.EventQueue;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.JPasswordField;

import javax.swing.border.EmptyBorder;

import com.sqc.dao.UserDao;

import com.sqc.model.User;

import com.sqc.util.DbUtil;

import com.sqc.util.StringUtil;

import javax.swing.GroupLayout;

import javax.swing.GroupLayout.Alignment;

import javax.swing.BoxLayout;

import java.awt.FlowLayout;

import javax.swing.JLabel;

import javax.swing.JOptionPane;

import java.awt.Font;

import javax.swing.ImageIcon;

import javax.swing.JTextField;

import javax.swing.LayoutStyle.ComponentPlacement;

import javax.swing.JButton;

import java.awt.event.ActionListener;

import java.sql.Connection;

import java.awt.event.ActionEvent;

import java.awt.event.MouseAdapter;

import java.awt.event.MouseEvent;

public class LoginFra extends JFrame {

private JPanel contentPane;

private JTextField userName_text;

private JPasswordField password_text;

private DbUtil dbUtil=new DbUtil();

private UserDao userDao=new UserDao();

/**

* Launch the application.

*/

public static void main(String[] args) {

EventQueue.invokeLater(new Runnable() {

public void run() {

try {

LoginFra frame = new LoginFra();

frame.setVisible(true);

} catch (Exception e) {

e.printStackTrace();

}

}

});

}

/**

* Create the frame.

*/

public LoginFra() {

setTitle("\u6854\u5B50\u9152\u5E97\u7BA1\u7406\u7CFB\u7EDF");

setResizable(false);

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

setBounds(100, 100, 557, 444);

contentPane = new JPanel();

contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));

setContentPane(contentPane);

JLabel password = new JLabel("\u5458\u5DE5\u53F7\uFF1A");

password.setFont(new Font("华文行楷", Font.PLAIN, 18));

password.setIcon(new ImageIcon(LoginFra.class.getResource("/image/head.png")));

JLabel label = new JLabel("\u5BC6 \u7801\uFF1A");

label.setFont(new Font("华文行楷", Font.PLAIN, 18));

label.setIcon(new ImageIcon(LoginFra.class.getResource("/image/password.png")));

userName_text = new JTextField();

userName_text.setColumns(10);

JButton btn_login = new JButton("\u767B \u5F55");

btn_login.setIcon(new ImageIcon(LoginFra.class.getResource("/image/accept.png")));

btn_login.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

loginActionPerformed(e);

}

});

btn_login.setFont(new Font("微软雅黑", Font.PLAIN, 18));

JButton btn_cancel = new JButton("\u6E05 \u9664");

btn_cancel.addActionListener(new ActionListener() {

public void actionPerformed(ActionEvent e) {

btn_cancelActionPerformed(e);

}

});

btn_cancel.setIcon(new ImageIcon(LoginFra.class.getResource("/image/refersh.png")));

btn_cancel.setFont(new Font("微软雅黑", Font.PLAIN, 18));

password_text = new JPasswordField();

JButton btnNewButton = new JButton("");

btnNewButton.setIcon(new ImageIcon(LoginFra.class.getResource("/image/theme.jpg")));

GroupLayout gl_contentPane = new GroupLayout(contentPane);

gl_contentPane.setHorizontalGroup(

gl_contentPane.createParallelGroup(Alignment.LEADING)

.addGroup(gl_contentPane.createSequentialGroup()

.addGap(69)

.addGroup(gl_contentPane.createParallelGroup(Alignment.TRAILING)

.addComponent(label)

.addComponent(password))

.addGap(39)

.addGroup(gl_contentPane.createParallelGroup(Alignment.LEADING, false)

.addComponent(btnNewButton, GroupLayout.PREFERRED_SIZE, 148, GroupLayout.PREFERRED_SIZE)

.addComponent(userName_text, GroupLayout.DEFAULT_SIZE, 202, Short.MAX_VALUE)

.addComponent(password_text))

.addContainerGap(127, Short.MAX_VALUE))

.addGroup(gl_contentPane.createSequentialGroup()

.addGap(93)

.addComponent(btn_login)

.addPreferredGap(ComponentPlacement.RELATED, 79, Short.MAX_VALUE)

.addComponent(btn_cancel, GroupLayout.PREFERRED_SIZE, 151, GroupLayout.PREFERRED_SIZE)

.addGap(67))

);

gl_contentPane.setVerticalGroup(

gl_contentPane.createParallelGroup(Alignment.LEADING)

.addGroup(gl_contentPane.createSequentialGroup()

.addGap(33)

.addComponent(btnNewButton, GroupLayout.PREFERRED_SIZE, 134, GroupLayout.PREFERRED_SIZE)

.addGap(27)

.addGroup(gl_contentPane.createParallelGroup(Alignment.BASELINE)

.addComponent(password)

.addComponent(userName_text, GroupLayout.PREFERRED_SIZE, 37, GroupLayout.PREFERRED_SIZE))

.addGap(40)

.addGroup(gl_contentPane.createParallelGroup(Alignment.BASELINE)

.addComponent(label)

.addComponent(password_text, GroupLayout.PREFERRED_SIZE, 37, GroupLayout.PREFERRED_SIZE))

.addPreferredGap(ComponentPlacement.RELATED, 21, Short.MAX_VALUE)

.addGroup(gl_contentPane.createParallelGroup(Alignment.BASELINE)

.addComponent(btn_login)

.addComponent(btn_cancel, GroupLayout.PREFERRED_SIZE, 54, GroupLayout.PREFERRED_SIZE))

.addGap(37))

);

contentPane.setLayout(gl_contentPane);

}

/**

* 登录事件处理

* @param e

*/

private void loginActionPerformed(ActionEvent evt) {

String userName=this.userName_text.getText();

String password=new String(this.password_text.getPassword());

if(StringUtil.isEmpty(userName)){

JOptionPane.showMessageDialog(null, "用户名不能为空！");

return;

}

if(StringUtil.isEmpty(password)){

JOptionPane.showMessageDialog(null, "密码不能为空！");

return;

}

User user=new User(userName,password);

Connection con=null;

try {

con=dbUtil.getCon();

User currentUser=userDao.login(con, user);

if(currentUser!=null){

dispose();

new MainFra().setVisible(true);

}else{

JOptionPane.showMessageDialog(null, "用户名或者密码错误！");

}

} catch (Exception e) {

// TODO Auto-generated catch block

e.printStackTrace();

}finally{

try {

dbUtil.closeCon(con);

} catch (Exception e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

}

/**

* 重置事件处理

* @param e

*/

private void btn_cancelActionPerformed(ActionEvent e) {

// TODO Auto-generated method stub

this.userName_text.setText("");

this.password_text.setText("");

}

}