Question

所以问题是这个。我有一个GUI打开一个JFileChooser并且用户选择一个文件，当命中OK时，一个新的类被调用（Amostra Sample = new Amostra（namefile），其中namefile是绝对路径）它将从文件中预处理一些数据在GUI上显示它。然后，用户将插入一些选项以对文件执行其余操作并保存。问题是，我无法访问JButton1中创建的对象“Sample”，并且由于处理过程非常耗时，因此访问已完成的工作将是理想的选择。任何提示？

public class FormatFiles extends javax.swing.JFrame {

    /** Creates new form FormatFiles */
    public FormatFiles() {
        initComponents();
    }



    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        // TODO add your handling code here:
        JFileChooser chooser = new JFileChooser();//Inicia Caixa Dialog
        FileNameExtensionFilter filter = new FileNameExtensionFilter("SNLT logs", "csv");//Restringe tipo de ficheiros  
        chooser.addChoosableFileFilter(filter);//Adiciona filtro á Caixa
        chooser.setAcceptAllFileFilterUsed(false);
        int returnVal = chooser.showOpenDialog(this);
        if(returnVal == JFileChooser.APPROVE_OPTION)  {
            try {
                File ficheiro = chooser.getSelectedFile();
                jLabel3.setText(ficheiro.getAbsolutePath()); 
                String namefile = ficheiro.getAbsolutePath();
                File openAs = new File(namefile);
                FileReader in = null;
                //Opens File
                try {
                    in = new FileReader(openAs);
                } catch (FileNotFoundException ex) {
                    Logger.getLogger(FormatFiles.class.getName()).log(Level.SEVERE, null, ex);
                }
                //Load file into jTextArea1
                try {
                    jTextArea1.read(in, openAs.toString());
                } catch (IOException ex) {
                    Logger.getLogger(FormatFiles.class.getName()).log(Level.SEVERE, null, ex);
                }
                //Calls Amostra
                Amostra Sample = new Amostra(namefile);
                String segundos = Double.toString(Sample.getsec());
                jLabel7.setText(segundos);

            } catch (FileNotFoundException ex) {
                Logger.getLogger(FormatFiles.class.getName()).log(Level.SEVERE, null, ex);
            } catch (IOException ex) {
                Logger.getLogger(FormatFiles.class.getName()).log(Level.SEVERE, null, ex);
            } catch (ParseException ex) {
                Logger.getLogger(FormatFiles.class.getName()).log(Level.SEVERE, null, ex);
            }
    }                                        
    }





    private void jButton3ActionPerformed(java.awt.event.ActionEvent evt) {                                         
        // TODO add your handling code here:
        String Accao = jTextField1.getText();
        JOptionPane.showMessageDialog(null,Accao);
        //Can't Access Sample from here...

    }                                        

    /**
     * @param args the command line arguments
     */



    public static void FormatFiles(String args[]) {
        java.awt.EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                new FormatFiles().setVisible(true);
            }
        });
    }
    // Variables declaration - do not modify                     
    private javax.swing.JButton jButton1;
    private javax.swing.JButton jButton3;
    private javax.swing.JLabel jLabel1;
    private javax.swing.JLabel jLabel2;
    private javax.swing.JLabel jLabel3;
    private javax.swing.JLabel jLabel4;
    private javax.swing.JLabel jLabel5;
    private javax.swing.JLabel jLabel6;
    private javax.swing.JLabel jLabel7;
    private javax.swing.JRadioButton jRadioButton1;
    private javax.swing.JScrollPane jScrollPane1;
    private javax.swing.JSeparator jSeparator1;
    private javax.swing.JTextArea jTextArea1;
    private javax.swing.JTextField jTextField1;
    private javax.swing.JTextField jTextField2;
    // End of variables declaration                   
}

Answer 1

将sample的声明移到方法之外，所以整个班级都可以访问它，同时将其改为以小写字母开头：

public class FormatFiles extends javax.swing.JFrame {
     ....
    Amostra sample;
     ....
    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
         ....
         sample = new Amostra(namefile);
         ....
    }
    ......
}

Answer 2

你不能只把它声明为实例变量吗？

为符合最佳实践，实例变量应为private，并且其名称应符合标准Java命名约定，以小写字母开头; e.g。

private Amostra sample;

访问类对象问题

2 个答案: