borrowbean.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 BorrowBean extends JPanel
{
 Connection con;
 private String username;
 private String bookname;
 private String borowdate;
 private String comment;
 public String getUsername()
 {
 	return username;
 }	
 public String getBookname()
 {
 	return bookname;
 }
 public String getBorrowdate()
 {
 	return borowdate;
 }
 public String getComment()
 {
 	return comment;
 }
 public void setUsername(String username)
 {
 	this.username=username;
 }
 public void setBookname(String bookname)
 {
 	this.bookname=bookname;
 }
 public void setBorrowdate(String date)
 {
 	this.borowdate=date;
 }
 public void setComment(String comment)
 {
 	this.comment=comment;
 }
  public boolean insert()
    {
    	BorrowBean bean=new BorrowBean();
        
    	try{
    		con = new DBManager().getConnection();
    		PreparedStatement pstm=con.prepareStatement("insert into 书籍借阅信息表(studentname,bookname,borrowdate,comment) values(?,?,?,?)");
    		pstm.setString(1,username);
    		pstm.setString(2,bookname);
    		pstm.setString(3,borowdate);
    		pstm.setString(4,comment);
    		pstm.executeUpdate();
    		return true;
    	}
    	catch(Exception e1)
    	{
    	System.out.println(e1.toString());
    	return false;	
    	}
    	
    }
      public boolean modify()
    {
         // String sql=null;
        	BorrowBean bean=new BorrowBean ();
    	try{
    		con = new DBManager().getConnection();
    	/*	if (username.equals(""))
    		{
    			if (bookname.equals(""))
    		 {
    			JOptionPane.showMessageDialog(null,"书名或用户名不能为空！");
    		 }
    		 else
    		 {
    		sql="update 书籍借阅信息表 set bookname=?,borrowdate=?,comment=? where  bookname='"+bookname+"'";	
    		 }
    			
    			
    		}
    		else
    		{
    			if (bookname.equals(""))
    		 {
    			sql="update 书籍借阅信息表 set bookname=?,borrowdate=?,comment=? where  studentname='"+username+"'";	
    		 }
    		 else
    		 {sql="update 书籍借阅信息表 set bookname=?,borrowdate=?,comment=? where  bookname='"+bookname+"' and studentname='"+username+"'";	
    		 }
    		
    		
    		}
    		*/
    	   PreparedStatement pstm=con.prepareStatement("update 书籍借阅信息表 set studentname=?,bookname=?,borrowdate=?,comment=? where  studentname='"+username+"'");
    		pstm.setString(1,username);
    		pstm.setString(2,bookname);
    		pstm.setString(3,borowdate);
    		pstm.setString(4,comment);
    
    		pstm.executeUpdate();
    		return true;
    	}
    	catch(Exception e1)
    	{
    		System.out.println(e1.toString());
    	return false;	
    	}
    }
   
}