import javax.swing.*;
import java.awt.*;
import java.sql.*;
import java.awt.event.*;
public class ScrollDisplay extends JFrame
implements ActionListener{
  JLabel lbRow=new JLabel("行數");
  JTextField tfRow = new JTextField();
  JButton btnQuery=new JButton("查詢");
  JPanel panel=new JPanel();
  JTextArea taInfo=new JTextArea();
  public ScrollDisplay()   {
    super("滾動顯示學生信息");
    setSize(320,260);
    this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE );
    panel.setLayout(new BorderLayout());
    panel.add(lbRow,BorderLayout.WEST);
    panel.add(tfRow,BorderLayout.CENTER);
    panel.add(btnQuery,BorderLayout.EAST);
    btnQuery.addActionListener(this);
    getContentPane().setLayout(new BorderLayout());
    getContentPane().add(panel,BorderLayout.NORTH);
    getContentPane().add(taInfo,BorderLayout.CENTER);
  }
  public void getRecord(int Row) throws SQLException{
    String URL,SQL;
    Connection con=null;
    try {
         Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
   }
   catch(ClassNotFoundException ex){
     taInfo.setText(ex.getMessage());
     System.exit(-1);
   }
   try{
     URL = "jdbc:odbc:學生信息管理";
     con = DriverManager.getConnection(URL);
     //創建一個可滾動但不可更新的結果集
     Statement stmt=con.createStatement(ResultSet.TYPE_SCROLL_SENSITIVE,
                                        ResultSet.CONCUR_READ_ONLY);
     SQL = "SELECT 學號,姓名,年齡,系別 FROM 學生信息表";
     ResultSet rs=stmt.executeQuery(SQL);
     rs.absolute(Row);//將游標移到指定的行
     taInfo.setText("");
     taInfo.setText(rs.getString("學號") + "\t");
     taInfo.append(rs.getString("姓名") + "\t");
     taInfo.append(String.valueOf(rs.getInt("年齡")) + "\t");
     taInfo.append(rs.getString("系別") + "\n");
     rs.close();
     stmt.close();
      }
       catch(SQLException ex){
         taInfo.setText(ex.getMessage());
      }
      finally{
        con.close();
      }
  }
  public static void main(String[] args)   {
    ScrollDisplay frame = new ScrollDisplay();
    frame.show();
  }
  public void actionPerformed(ActionEvent e) {
    if(e.getSource()==btnQuery){
      String strRow=tfRow.getText();//獲取用戶輸入的行號
      int intRow=Integer.parseInt((strRow));
      try {
        getRecord(intRow);
      }
      catch (SQLException ex) {
        taInfo.setText(ex.getMessage());
      }
    }
  }
}