package sfms;import java.awt.*;import javax.swing.*;import java.sql.*;import java.awt.event.*;public class delete extends JFrame implements ActionListener{   JButton yesB,cancelB;   JTextField text1;   String SNO;   mainWindow parent3;  public delete(mainWindow f3){    parent3=f3;    Container c=this.getContentPane();    c.setLayout(new GridLayout(3,1));    c.setFont(new Font("true",Font.TRUETYPE_FONT,13));    JPanel p1=new JPanel();    JPanel p2=new JPanel();    //first,add the label    JLabel label1=new JLabel("刪除學生檔案",SwingConstants.CENTER);    label1.setFont(new Font("TRUE",Font.TRUETYPE_FONT,20));    label1.setForeground(Color.blue);    c.add(label1);    //set the input dialog frame    JLabel label2=new JLabel("請輸入學生號");    text1=new JTextField(10);    p1.add(label2);    p1.add(text1);    c.add(p1);    //set the buttons     yesB=new JButton("確定");     cancelB=new JButton("退出");    p2.add(yesB);    p2.add(cancelB);    c.add(p2);    //register frames as listener for button events    yesB.addActionListener(this);    cancelB.addActionListener(this);    this.setSize(400,300);    this.setTitle("刪除學生檔案");    this.setVisible(true);    //create anonymous inner class to handle window closing event    this.addWindowListener(new WindowAdapter()    {      public void windowClosing( WindowEvent event)      {shutDown();}    }    );      }      //action performed when a Button is invoked   public void actionPerformed(ActionEvent e){     if(e.getSource()==yesB){       del();     }     if(e.getSource()==cancelB){       shutDown();     }   }   private void del(){    SNO=text1.getText();    try{      Class.forName("oracle.jdbc.OracleDriver").newInstance();      String url="jdbc:oracle:thin:@localhost:1521:SFMS";      Connection conn=DriverManager.getConnection(url,"df","1234");      String sql="DELETE FROM DF.FILEINFO WHERE STNO='"+ SNO +"'";      PreparedStatement ps=conn.prepareStatement(sql);      ps.executeUpdate(sql);      conn.close();      JOptionPane.showMessageDialog(this,"刪除成功!");    }    catch(SQLException e){      System.out.println("Error Code: "+ e.getErrorCode());      System.out.println("Message="+e.getMessage()); }    catch(Exception e){  e.printStackTrace();}   }   private void shutDown(){     parent3.setVisible(true);     this.dispose();   }/*public static void main(String args[]){     delete dd=new delete();   }      */}