showframe.java

代码是自己我的代码不是网上down的。是自己写的。里面有很多值得学习的知识点。还有一些javabean组件。不算自己写的JAR文件

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.sql.*;
public class ShowFrame extends JFrame implements ActionListener
{
	private JLabel name;
	private JLabel password;
	private JTextField myname;
	private JPasswordField mypassword;
	private JButton ok;
	private JButton cancel;
	private ResultSet rs;
	private DBManager db=new DBManager();
	public ShowFrame()
	{
	setTitle("登陆界面");
	setSize(200,120);
	Dimension screen=getToolkit().getScreenSize();
	
	setLocation((screen.width-getSize().width)/2,(screen.height-getSize().height)/2);
	setLayout(new GridLayout(3,2,2,2));
	name=new JLabel("            用户名");
	password=new JLabel("            密 码");
    myname=new JTextField(16);
	mypassword=new JPasswordField(16);
	ok=new JButton("确定");
	cancel=new JButton("取消");

	getContentPane().add(name);
	getContentPane().add(myname);
	getContentPane().add(password);
	getContentPane().add(mypassword);
	getContentPane().add(ok);
	getContentPane().add(cancel);
	pack();
	addWindowListener(
			new WindowAdapter()
			{
				public void windowClosing(WindowEvent e)
				{
					System.exit(0);
				}
			}
			);
	   
     ok.addActionListener(this);
     cancel.addActionListener(
     	new ActionListener()
     	{
     			public void actionPerformed(ActionEvent evt){
	            System.exit(0);  //退出程序
	       }
     	}
     	);
		show(); 
	}
	public void actionPerformed(ActionEvent e)
	{
	  	
	  	 if (myname.getText().trim().equals(""))
	  	 {
	  	 	JOptionPane.showMessageDialog(ShowFrame.this,"用户名不能为空！");
	  	 	return;
	  	 }
	  	
	    if(mypassword.getText().trim().equals(""))
	  	 {
	  	 	JOptionPane.showMessageDialog(ShowFrame.this,"密码不能为空！");
	  	 	return;
	  	 }
	  	 String strSQL;
	  	 strSQL="select * from 用户表 where username='"+myname.getText().trim()+"' and password='"+mypassword.getText().trim()+"'";
	  	 rs=db.getResult(strSQL);
	  	 try{
	  	 	
	  	 	if (rs.next())
	  	 {
	  	 	this.dispose();
	  	 	new BookManagerMain();
	  	 	//	String message="您的用户名："+rs.getString("username")+"\n您的密码："+rs.getString("password");  //消息字符串
   			 //   JOptionPane.showMessageDialog(null, message);  //显示消息
   			 
	  	 }
	  	 else
	  	 {
	  	 		JOptionPane.showMessageDialog(null,"用户名不存在或密码不正确!");
	  	 }
	  	 }
	  	 
	  	catch(SQLException ex1)
	  	{
	  		
	  	}
	  

        
	}
	
	public static void main(String[] args)
	{
		new ShowFrame();
	
	}
}