bookdeleframe.java

java小程序

import java.awt.*;
import javax.swing.*;
import javax.swing.event.*;
import java.awt.event.*;
import java.sql.*;
public class BookDeleFrame extends JFrame implements ActionListener
{
private Container c;
private JPanel panel1,panel2;
private JLabel nameLabel;
private JTextField nameText;
private JButton ok,exit;

public BookDeleFrame()
{
super("删除书籍");
c=getContentPane();
c.setLayout(new BorderLayout());
nameLabel=new JLabel("请输入要删除的书名：",JLabel.CENTER);
nameText=new JTextField(12);
ok=new JButton("确定");
exit=new JButton("退出");
panel1=new JPanel();
panel1.setLayout(new GridLayout(2,1));
panel1.add(nameLabel);
panel1.add(nameText);
panel2=new JPanel();
panel2.add(ok);
panel2.add(exit);
ok.addActionListener(this);
exit.addActionListener(this);
c.add(panel1,BorderLayout.CENTER);
c.add(panel2,BorderLayout.SOUTH);
setSize(150,80);
setVisible(true);
}
public void actionPerformed(ActionEvent e)
{
int findFlag=0;
if(nameText.getText().equals(""))
JOptionPane.showMessageDialog(null,"用户名不能为空");
else
{
//连接数据库
try
{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
}
catch(ClassNotFoundException e1)
{
System.out.println(e1.getMessage());
}
try
{
Connection con=DriverManager.getConnection("jdbc:odbc:bookbase");
Statement stmt=con.createStatement();
ResultSet rs=stmt.executeQuery("select bookName from bookInfo");
while(rs.next())
{
if(nameText.getText().equals(rs.getString("bookName")))
{
findFlag=1;
break;
}
}
stmt.close();
con.close();
}
catch(SQLException ex)
{
System.out.println("SQLException:"+ex.getMessage());
}
//连接数据库结束
}

if(e.getSource()==ok)
{
if(findFlag==1)
{
//连接数据库
try
{
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
}
catch(ClassNotFoundException e1)
{
System.out.println(e1.getMessage());
}
try
{
Connection con=DriverManager.getConnection("jdbc:odbc:bookbase");
Statement stmt=con.createStatement();
PreparedStatement pstmt=con.prepareStatement("delete * from bookInfo where bookName=?");
pstmt.setString(1,nameText.getText());
pstmt.executeUpdate();
stmt.close();
con.close();
}
catch(SQLException ex)
{
System.out.println("SQLException:"+ex.getMessage());
}
//数据库连接结束
}
else if(findFlag==0)
{
if(nameText.getText().equals(""))
;
else
JOptionPane.showMessageDialog(null,"此书籍不存在!");
}
}
else if(e.getSource()==exit)
this.dispose();
}
}