borrowsearch.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.*;
import java.util.*; 
import javax.swing.table.*;

public class BorrowSearch extends JFrame
{
	ResultSet rs;
	private DBManager db=new DBManager();
	private JPanel centerpanel;
	private JScrollPane scrollpane;
	private JLabel bookname;
	private JLabel username;
	private JTextField mybookname;
    private JTextField myusername;
	private JButton ok;
    private Vector tempvector=new Vector(1,1);
    DefaultTableModel model=new DefaultTableModel();
    JTable table=new JTable(model);
	public BorrowSearch()
	{
	centerpanel=new JPanel(new GridLayout(1,5));
	scrollpane=new JScrollPane();
	bookname=new JLabel("书 名");
	username=new JLabel("借阅者");
	mybookname=new JTextField(16);
    myusername=new JTextField(16);
	ok=new JButton("查询");
	centerpanel.add(username);
	centerpanel.add(myusername);
	centerpanel.add(bookname);
	centerpanel.add(mybookname);
    centerpanel.add(ok);
    //model中加入列名
    model.addColumn("借阅者");
    model.addColumn("书名");
   	model.addColumn("借阅日期");
   	model.addColumn("还入日期");
   	model.addColumn("备注");		
    scrollpane.getViewport().add(table,null);
	getContentPane().add(centerpanel,"North");
	getContentPane().add(scrollpane,"Center");
	setTitle("借阅信息查询");
	setSize(500,500);
	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);
				}
			}
			);

		ok.addMouseListener(
			new MouseAdapter()
			{
				public void mouseClicked(MouseEvent e)
				{
					BookSearch();
				}
			}
			);

	
		show();
	}
	public void BookSearch()
	{
		String sql;
		boolean isfirst=true;
		//检验书目是否存在
		sql="select * from 书籍借阅信息表";
  		if(!myusername.getText().trim().equals(""))
		{
		 sql="select * from 书籍借阅信息表 where studentname='"+myusername.getText().trim()+"'";
		 isfirst=false;
		}
	
		if(!mybookname.getText().trim().equals(""))
		{
			if(isfirst)
			{
			sql="select * from 书籍借阅信息表 where bookname='"+mybookname.getText().trim()+"'";
		    isfirst=false;	
			}
		   else
		   {
		   	 sql=" select * from 书籍借阅信息表 and bookname='"+mybookname.getText().trim()+"'";
		   }
		}
		
	
		
		//执行对数据库的查询
		rs=db.getResult(sql);
	    boolean isexist=false;
	    try
	    {
	    	isexist=rs.first();
	    }
	    catch(SQLException ex1)
	    {
	    	 JOptionPane.showMessageDialog(null,"ex1.toString()"+ex1.toString());	
	    }
		//若书目不存在，提示警告信息提醒用户
	    if(!isexist)
	    {
	    JOptionPane.showMessageDialog(null,"书库中没有书目，请确认");	
		 return;	
	    }
	    //若存在，执行显示书目
	    	//清空model中的对象
	    else
	    {
	    
				for(int i=0;i<model.getRowCount();i++)
				{
					model.removeRow(i);
				}
				try{
					//移动光标到零的位置
					rs.beforeFirst();
					//逐条将查询结果显示在table中
					while(rs.next())
					{
						tempvector=new Vector(1,1);
						tempvector.add(rs.getString("studentname"));
						tempvector.add(rs.getString("bookname"));
						tempvector.add(rs.getString("borrowdate"));
						tempvector.add(rs.getString("returndate"));
						tempvector.add(rs.getString("comment"));
						model.addRow(tempvector);	
					}
				}
				catch(SQLException ex)
		{
		 JOptionPane.showMessageDialog(null,"发生错误!");
		 	
		}
	    }

	}

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

}