是否可以使用数据库中的相似名称打开文件？

因此，当我单击一个按钮（“开放课程”）时，将出现另一个类的JFrame（使用.setVisible（true））。在该JFrame中，有一个JTable（tblOpenLesson）和两个按钮（btnOpenLesson和btnCancel）。

现在我要发生的是，当我单击“打开课程”按钮时，它将执行以下操作：1.更新表以将sqlite数据库（课程）反映到JTable中。2.通过获取文件从表中打开所选文件名称（与数据库中的名称相同），并将其用于FileReader函数。

但是，这给了我错误：

线程“ AWT-EventQueue-0”中的异常java.lang.ArrayIndexOutOfBoundsException：javax.java.util.Vector.elementData（Vector.java:737）处为java.util.Vector.elementAt（Vector.java:480）处为-1 mainWindow.openLesson.access $ 000（openLesson.java:19）上mainWindow.openLesson.btnOpenLessonPopUpActionPerformed（openLesson.java:135）上的.swing.table.DefaultTableModel.getValueAt（DefaultTableModel.java:648）at mainWindow.openLesson $ 1.actionPerformed（ openLesson.java:60），位于javax.swing.AbstractButton.fireActionPerformed（AbstractButton.java:2022），javax.swing.AbstractButton $ Handler.actionPerformed（AbstractButton.java:2348），javax.swing.DefaultButtonModel.fireActionPerformed（DefaultButtonModel.java） ：402），位于javax.swing.plaf处的javax.swing.DefaultButtonModel.setPressed（DefaultButtonModel.java:259）。java.awt.Component.processMouseEvent（Component.java:6539）的basic.BasicButtonListener.mouseReleased（BasicButtonListener.java:252）在java.awt.Component.processEvent的javax.swing.JComponent.processMouseEvent（JComponent.java:3324） （Component.java:6304）at java.awt.Container.processEvent（Container.java:2239）at java.awt.Component.dispatchEventImpl（Component.java:4889）at java.awt.Container.dispatchEventImpl（Container.java： 2297）在java.awt.Component.dispatchEvent（Component.java:4711）在java.awt.LightweightDispatcher.retargetMouseEvent（Container.java:4904）在java.awt.LightweightDispatcher.processMouseEvent（Container.java:4535）在java。位于java.awt.Window的java.awt.Container.dispatchEventImpl（Container.java:2283）的awt.LightweightDispatcher.dispatchEvent（Container.java:4476）。在Java.awt.EventQueue.access $ 500（EventQueue。 java.awt.EventQueue $ 3.run（java：97）（java.awt.EventQueue $ 3.run（EventQueue.java:703）at java.security.AccessController.doPrivileged（Native Method） Java上的.security.ProtectionDomain $ JavaSecurityAccessImpl.doIntersectionPrivilege（ProtectionDomain.java:74）在java.awt.EventQueue $ 4.run（ProtectionDomain.java:84）在java.security.ProtectionDomain $ JavaSecurityAccessImpl.doIntersectionPrivilege（ProtectionDomain.java:84）在Java .awt.EventQueue $ 4.run（EventQueue.java:731）在java.security.AccessController.doPrivileged（本机方法）在java.security。java.awt.EventQueue.dispatchEvent（EventQueue.java:730）处的ProtectionDomain $ JavaSecurityAccessImpl.doIntersectionPrivilege（ProtectionDomain.java:74）在java.awt.EventDispatchThread.pumpEventsForFilter处在java.awt.EventDispatchThread.pumpOneEventForFilters（EventDispatchThread.java:205）处（EventDispatchThread.java:116）在java.awt.EventDispatchThread.pumpEventsForHierarchy（EventDispatchThread.java:105）在java.awt.EventDispatchThread.pumpEvents（EventDispatchThread.java:101）在java.awt.EventDispatchThread.pumpEvents（EventDispatchThread.java： 93）在java.awt.EventDispatchThread.run（EventDispatchThread.java:82）205），位于java.awt.EventDispatchThread.pumpEventsForFilter（EventDispatchThread.java:116），位于java.awt.EventDispatchThread.pumpEvents（EventDispatchThread.java:101），位于java.awt.EventDispatchThread.pumpEventsForHierarchy（EventDispatchThread.java:105）。 awt.EventDispatchThread.pumpEvents（EventDispatchThread.java:93）at java.awt.EventDispatchThread.run（EventDispatchThread.java:82）205），位于java.awt.EventDispatchThread.pumpEventsForFilter（EventDispatchThread.java:116），位于java.awt.EventDispatchThread.pumpEvents（EventDispatchThread.java:101），位于java.awt.EventDispatchThread.pumpEventsForHierarchy（EventDispatchThread.java:105）。 awt.EventDispatchThread.pumpEvents（EventDispatchThread.java:93）at java.awt.EventDispatchThread.run（EventDispatchThread.java:82）

我试图寻找解决办法，但在这里停留了3天却无济于事。

这是弹出式JFrame的代码：

@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">                          
// </editor-fold>                        

private void btnCancelOpenLessonActionPerformed(java.awt.event.ActionEvent evt) {                                                    
    this.setVisible(false);
}                                                   

private void btnOpenLessonPopUpActionPerformed(java.awt.event.ActionEvent evt) {                                                   

    updateDBlessons(); // update list

    String[] fileName = null;

    int selectedColumn = tblOpenLesson.getSelectedColumn();
    int selectedRow = tblOpenLesson.getSelectedRow();
    try {
        Class.forName("org.sqlite.JDBC");
        Connection con = DriverManager.getConnection("jdbc:sqlite:sql_items.sqlite");
        Statement stmtGetLesson = con.createStatement();
        ResultSet rs = stmtGetLesson.executeQuery("SELECT * FROM lessons WHERE lesson_id  = '" + tblOpenLesson.getModel().getValueAt(selectedRow, selectedColumn) + "';");

        if (rs.next()) {
            fileName[0] = rs.getString("lesson");
        }
    } catch (SQLException e) {
        JOptionPane.showMessageDialog(null, e);
    } catch (ClassNotFoundException ex) {
        Logger.getLogger(openLesson.class.getName()).log(Level.SEVERE, null, ex);
    }

        try {
        FileReader fr = new FileReader("Lessons\\" + fileName[0] + ".txt");
            try (BufferedReader br = new BufferedReader(fr)) {
            mainScreen.lessonPane.read(br, null); //  lessonPane is from another class
            br.close();
            }
        } catch (IOException e) {
        System.out.println(e);
        this.setVisible(false);
        }


}                                                  


public static void main(String args[]) {
    /* Set the Nimbus look and feel */
    //<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
    /* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
     * For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html 
     */

    //</editor-fold>

    //</editor-fold>

    /* Create and display the form */
    java.awt.EventQueue.invokeLater(() -> {
        new openLesson().setVisible(false);
    });
}

public void updateDBlessons() {
    try {
        Class.forName("org.sqlite.JDBC");
        Connection  con = DriverManager.getConnection("jdbc:sqlite:sql_items.sqlite");
        Statement stmt = con.createStatement();
        ResultSet rs = stmt.executeQuery("SELECT * FROM lessons");
        DefaultTableModel dtm = (DefaultTableModel) tblOpenLesson.getModel();
        dtm.setRowCount(0);

        while(rs.next()){
            Object o[] = {rs.getString("lesson")};
            dtm.addRow(o);
        }
    } catch (ClassNotFoundException | SQLException e) {

    }
}


// Variables declaration - do not modify                     
private javax.swing.JButton btnCancelOpenLesson;
private javax.swing.JButton btnOpenLessonPopUp;
private javax.swing.JLabel jLabel1;
private javax.swing.JScrollPane jScrollPane1;
private javax.swing.JPanel pnlOpenLesson;
private javax.swing.JTable tblOpenLesson;
// End of variables declaration                   
}

我开始认为这是不可能的。如果是这样，请告诉我该怎么办。非常感谢

问题来源：Stack Overflow