package droptable;import com.borland.jbcl.layout.*;import java.awt.*;import java.awt.event.*;import java.sql.*;import javax.swing.*;/**   * Title:				刪除數據庫中的表程序   * Description:			教學示范   * Copyright:				Copyright (c) 2003   * Company:				北京師范大學計算機系   * @author				孫一林   * @version				1.0   */public class DropTableFrame extends JFrame {  private JPanel contentPane;  private XYLayout xYLayout1 = new XYLayout();       // 構造XYLayout布局管理器  // 創建顯示信息使用的組件  private Label label1 = new Label();  private TextField droptablenameField = new TextField();  private Button droptableButton = new Button();  Connection connection = null;                      // 聲明Connection接口對象connection  Statement statement = null;                        // 定義查詢數據庫的Statement對象  public DropTableFrame() {    enableEvents(AWTEvent.WINDOW_EVENT_MASK);    try {      jbInit();    }    catch(Exception e) {      e.printStackTrace();    }  }  private void jbInit() throws Exception  {    contentPane = (JPanel) this.getContentPane();    // 初始化組件    label1.setText("刪除表名稱：");    contentPane.setLayout(xYLayout1);    this.setSize(new Dimension(400, 300));    this.setTitle("刪除數據庫中的表");    droptableButton.setLabel("刪除表");    droptableButton.addActionListener(new java.awt.event.ActionListener() { // droptableButton的事件監聽方法      public void actionPerformed(ActionEvent e) {        droptableButton_actionPerformed(e);      }    });    contentPane.add(label1, new XYConstraints(56, 73, 85, 33));    contentPane.add(droptablenameField, new XYConstraints(164, 73, 108, 35));    contentPane.add(droptableButton, new XYConstraints(164, 178, 102, 37));  }  protected void processWindowEvent(WindowEvent e) {    super.processWindowEvent(e);    if (e.getID() == WindowEvent.WINDOW_CLOSING) {      System.exit(0);    }  }  void droptableButton_actionPerformed(ActionEvent e) {// 處理droptableButton事件    try {      Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");  // 實例化JDBC-ODBC橋的驅動      String url = "jdbc:odbc:TestDbStu";             // 設置連接字符串      connection = DriverManager.getConnection(url);  // 連接數據庫      statement = connection.createStatement();      String sql="drop table  "+droptablenameField.getText() ;      statement.executeUpdate(sql);                   // 執行刪除數據庫中的表語句      droptablenameField.setText("");    }    catch(SQLException ex){                           // 捕捉異常      System.out.println("\nERROR:----- SQLException -----\n");      while (ex != null) {        System.out.println("Message:   " + ex.getMessage());        System.out.println("SQLState:  " + ex.getSQLState());        System.out.println("ErrorCode: " + ex.getErrorCode());        ex = ex.getNextException();      }    }    catch(Exception ex ) {      ex.printStackTrace();    }    finally {      try {        if(statement != null) {          statement.close();                                  // 關閉Statement接口實例        }        if(connection != null) {          connection.close();                                 // 關閉Connection接口實例        }      }      catch (SQLException ex)  {        System.out.println("\nERROR:----- SQLException -----\n");        System.out.println("Message:   " + ex.getMessage( ));        System.out.println("SQLState:  " + ex.getSQLState());        System.out.println("ErrorCode: " + ex.getErrorCode());      }    }  }}