huanshuedit.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 HuanshuEdit extends JFrame
{
	ResultSet rs;
	private DBManager db=new DBManager();

	private JPanel centerpanel;
	private JPanel southpanel;
	private JPanel northpanel;
	private JLabel username;
	private JLabel bookname;
	private JLabel date;
	private JLabel huandate;
	private JLabel auther;
	private JLabel comment;
	private JTextField mybookname;
    private JTextField myusername;
    private JTextField mydate;
    private JTextField myhuandate;
    private JTextField mycomment;
	private JButton ok;
	private JButton cancel;
	private JButton update;
	private JButton clear;
    private JLabel tishi;
	public HuanshuEdit()
	{
	
	tishi=new JLabel("输入借阅者姓名或书名点击确定，将调出此书相关信息");
	northpanel=new JPanel(new BorderLayout());
	centerpanel=new JPanel(new GridLayout(7,2));
	southpanel=new JPanel(new GridLayout(1,1));
	username=new JLabel("还书者姓名");
	bookname=new JLabel("书 名");
	date=new JLabel("借阅日期");
	huandate=new JLabel("还入日期");
	comment=new JLabel("备 注");
	myusername=new JTextField(16);
    mybookname=new JTextField(16);
    mydate=new JTextField(16);
    myhuandate=new JTextField(16);
    mycomment=new JTextField(16);
	ok=new JButton("确定");
	cancel=new JButton("退出");
	clear=new JButton("清空");
    update=new JButton("更新");
	centerpanel.add(username);
	centerpanel.add(myusername);
	centerpanel.add(bookname);
	centerpanel.add(mybookname);
	centerpanel.add(date);
	centerpanel.add(mydate);
	centerpanel.add(huandate);
	centerpanel.add(myhuandate);
	centerpanel.add(comment);
	centerpanel.add(mycomment);
	southpanel.add(clear);
	southpanel.add(ok);
	southpanel.add(update);
	southpanel.add(cancel);
	northpanel.add(tishi,"Center");
	getContentPane().add(northpanel,"North");
	getContentPane().add(centerpanel,"Center");
	getContentPane().add(southpanel,"South");
	mydate.setEnabled(false);
	myhuandate.setEnabled(false);
	mycomment.setEnabled(false);
	update.setEnabled(false);
	setTitle("借阅信息修改");
	setSize(300,260);
	Dimension screen=getToolkit().getScreenSize();
	setLocation((screen.width-getSize().width)/2,(screen.height-getSize().height)/2);
		addWindowListener(
			new WindowAdapter()
			{
				public void windowClosing(WindowEvent e)
				{
					System.exit(0);
				}
			}
			);
		cancel.addActionListener(
			new ActionListener()
			{
				public void actionPerformed(ActionEvent e)
				{
					dispose();
				}
			}
			);
		ok.addActionListener(
			new ActionListener()
			{
				public void actionPerformed(ActionEvent e)
				{
					BookSearch();
				}
			}
			);
		clear.addActionListener(
			new ActionListener()
			{
				public void actionPerformed(ActionEvent e)
				{
					BookClear();
				}
			}
			);	
	  update.addActionListener(
			new ActionListener()
			{
				public void actionPerformed(ActionEvent e)
				{
					BookUpdate();
				}
			}
			);		
		show();
	}
	public void BookSearch()
	{
		String sql="";
		if(mybookname.getText().trim().length()==0 && myusername.getText().trim().length()==0)
		{
			JOptionPane.showMessageDialog(null,"至少输入一个检索条件！");
			return;
		}
		//定义变量，用来判断是否是第一个查询条件
		boolean isfirst=true;
	//	sql="select * from 书籍借阅信息表";
		//如果学生姓名的查询条件不为空
		if (myusername.getText().trim().length()!=0)
	
		{
			sql="select * from 书籍借阅信息表 where studentname='"+myusername.getText().trim()+"'";
			isfirst=false;
		}
		//如果书名的查询条件不为空
		if(mybookname.getText().trim().length()!=0)
		{	//如果是第一个查询条件
			if(isfirst)
			{
			sql="select * from 书籍借阅信息表 where bookname='"+mybookname.getText().trim()+"'";	
			}
			else
			{
			sql="select * from 书籍借阅信息表 where studentname='"+myusername.getText().trim()+"' and  bookname='"+mybookname.getText().trim()+"'";	
			}
		}
	
		//执行数据库的查询操作
		rs=db.getResult(sql);
		try{
			//判断返回的结果集是否为空，若不为空显示第一条记录
			if(!rs.equals(null))
		
			{
				mydate.setEnabled(true);
				myhuandate.setEnabled(true);
	            mycomment.setEnabled(true);
	            update.setEnabled(true);
				rs.first();
				myusername.setText(rs.getString("studentname"));
		 		mybookname.setText(rs.getString("bookname"));
		 	    mydate.setText(rs.getString("borrowdate"));
		 	    myhuandate.setText(rs.getString("returndate"));
		 		mycomment.setText(rs.getString("comment"));
			}
			else
			{
				JOptionPane.showMessageDialog(null,"无此记录！");
			}
		}
		catch(SQLException ex1)
		 	{//若出现异常，弹出警告对话框
		 	JOptionPane.showMessageDialog(null,"发生错误！");
		 	}
		
		
		
		
	}
	public void BookClear()
	{
		mybookname.setText("");
		myusername.setText("");
		mydate.setText("");
		myhuandate.setText("");
		mycomment.setText("");
	}
	public void BookUpdate()
	{
		String sql;
		sql="update 书籍借阅信息表 set studentname='"+myusername.getText().trim()+"',bookname='"+mybookname.getText().trim()+"',borrowdate='"+mydate.getText().trim()+"',returndate='"+myhuandate.getText().trim()+"', comment='"+mycomment.getText().trim()+"' where studentname='"+myusername.getText().trim()+"' and bookname='"+mybookname.getText().trim()+"'";

	 if(db.executeSql(sql))
	 {
	 JOptionPane.showMessageDialog(null,"成功更新！");
	 }
	 else
	 {
	 JOptionPane.showMessageDialog(null,"更新失败，请重新操作！");
	 }
	}
	public static void main(String[] args)
	{
		new HuanshuEdit();
	}
}