userbean.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.sql.*;
import javax.swing.*;
public class UserBean extends JPanel
{
	private String username;
	private String pwd;
	private String power;
	Connection con=null;
	Statement smt=null;
	ResultSet rs=null;
	public String getUsername()
	{
		return username;
	}
	public String getPwd()
	{
		return pwd;
	}

	public String getPower()
	{
		return power;
	}
	public void setUsername(String name)
	{
		this.username=name;
	}	
	public void setPwd(String pwd)
	{
		this.pwd=pwd;
	}

    public void setPower(String power)
    {
    	this.power=power;
    }
    public boolean insert()
    {
    	UserBean bean=new UserBean();
        
    	try{
    		con = new DBManager().getConnection();
    		PreparedStatement pstm=con.prepareStatement("insert into 用户表(username,password,power) values(?,?,?)");
    		pstm.setString(1,username);
    		pstm.setString(2,pwd);
    		pstm.setString(3,power);
    		pstm.executeUpdate();
    		return true;
    	}
    	catch(Exception e1)
    	{
    	System.out.println(e1.toString());
    	return false;	
    	}
    	
    }
    public boolean delete()
    {
    UserBean bean=new UserBean();
        
    	try{
    		con = new DBManager().getConnection();
    		PreparedStatement pstm=con.prepareStatement("delete from  用户表 where username=?");
    		pstm.setString(1,username);
    		pstm.executeUpdate();
    		return true;
    	}
    	catch(Exception e1)
    	{
    	return false;	
    	}	
    }
    public boolean modify()
    {
    	UserBean bean=new UserBean();
        
    	try{
    		con = new DBManager().getConnection();
    		PreparedStatement pstm=con.prepareStatement("update 用户表 set username=?,password=?,power=? where username='"+username+"'");
    		pstm.setString(1,username);
    		pstm.setString(2,pwd);
    		pstm.setString(3,power);
    		pstm.executeUpdate();
    		return true;
    	}
    	catch(Exception e1)
    	{
    	return false;	
    	}
    }
    public boolean isnull()
    {
    	UserBean bean=new UserBean();
        
    	try{
    		con = new DBManager().getConnection();
    		smt=con.createStatement();
    		rs=smt.executeQuery("select * from  用户表 where username='"+username+"'");
    		if(rs.next())
    		{
    			return false;
    		}
    		
    	}
    	catch(Exception e1)
    	{
    
    	}
    	return true;
    }
}