returnbookfrm.java

在程序的Borlistbookfrm.java中实现打印功能

import java.util.*;
import java.awt.*;
import java.io.*;
import java.net.*;
import java.sql.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.Date;
class Returnbookfrm extends JFrame implements ActionListener
{
	JLabel l_msg,l_user,l_bookname,l_data;
	JTextField t_user,t_data;
	JButton b_enter,b_clear,b_back,b_search;
	JPanel pan1,pan2,pan3,pan4,pan6;
	Choice c_bookname;
	
	Date d;
	NetConn sql;
	Statement sqll;
	ResultSet rs;
	
	Returnbookfrm()
	{
		super("还书窗口");
		l_msg      =new JLabel("还书窗口    ");
		l_user     =new JLabel("还书学生：");
		l_bookname =new JLabel("书籍名称：");
		l_data     =new JLabel("还书日期：");
		t_user     =new JTextField("",12);
		c_bookname =new Choice();
		t_data     =new JTextField("",12);
		d=new Date();
		t_data.setText(d.toLocaleString());
		b_search   =new JButton("查询");
		b_enter    =new JButton("确定");
		b_clear    =new JButton("清除");
		b_back     =new JButton("返回");
		b_search.addActionListener(this);
		b_enter.addActionListener(this);
		b_clear.addActionListener(this);
		b_back.addActionListener(this);
		pan1=new JPanel();pan2=new JPanel();pan3=new JPanel();pan4=new JPanel();pan6=new JPanel();
		pan1.add(l_msg);pan2.add(l_user);pan2.add(t_user);pan2.add(b_search);pan3.add(l_bookname);pan3.add(c_bookname);
		pan4.add(l_data);pan4.add(t_data);pan6.add(b_enter);pan6.add(b_clear);pan6.add(b_back);
		setLayout(new GridLayout(5,1));
		add(pan1);add(pan2);add(pan3);add(pan4);add(pan6);
		//setBounds(400,100,400,500);
		
		this.pack();
		this.setLocation(this.getToolkit().getScreenSize().width/2-this.getWidth()/2,this.getToolkit().getScreenSize().height/2-this.getHeight()/2);
		
		sql=new NetConn();
	}
	public void actionPerformed(ActionEvent ed)
	{
		
		if(ed.getSource()==b_back)
		{
			if(ed.getSource()==b_back)
			{
				dispose();
			}
		}
		
		else if(ed.getSource()==b_clear)
		{
			t_user.setText("");
			l_msg=new JLabel("还书窗口    ");
		}
		
		else if(ed.getSource()==b_enter)
		{
			
			try
			{
				sqll=sql.connect();
				int num;
				String s0=new String();
				String a1="'"+t_data.getText()+"'";
				String a3="'"+t_user.getText()+"'";
				String a4="'"+c_bookname.getSelectedItem()+"'";
				String a5="'"+"y"+"'";
				
				rs=sqll.executeQuery("SELECT * FROM books where bookname="+a4);
				while(rs.next())
				{
				    s0=rs.getString(6);
				}
				
				num=Integer.parseInt(s0);
				num++;
				s0=Integer.toString(num);
				
				String tem="UPDATE books set conun="+s0+" where bookname="+a4;
				sqll.executeUpdate(tem);
				
				String temp="update bookbrowse set returndata ="+a1+", isreturn ="+a5+" where studentname ="+a3+" and bookname="+a4;
				sqll.executeUpdate(temp);
				
				l_msg.setText("还书成功！");
			}
			catch(SQLException eg)
			{}
		}
		
		else if(ed.getSource()==b_search)
		{
			c_bookname.removeAll();
			
			try
			{
				sqll=sql.connect();
			    
				String s0="'"+t_user.getText()+"'";
				
				String temp="select * from bookbrowse where studentname="+s0+" and isreturn="+"'"+"n"+"'";
				rs=sqll.executeQuery(temp);
				
				while(rs.next())
				{
					c_bookname.add(rs.getString(3));
				}
				
				l_msg.setText("查询成功！");
			}
			catch(SQLException es)
			{}
		}
	}
}