訪問類對象問題

Question

所以問題是這樣的。我有一個GUI打開一個JFileChooser，用戶選擇一個文件，當命中時，一個新的類被調用（Amostra Sample = new Amostra（namefile），其中namefile是絕對路徑），並且它將預處理文件中的一些數據，將其顯示在GUI上。然後，用戶將插入一些選項來對文件的其餘操作進行預處理並保存。問題是，我無法訪問JButton1中創建的對象「Sample」，並且由於處理過程非常耗時，訪問已完成的工作將是理想的選擇。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

移動的sample聲明的方法之外，因此這將是由全班訪問，也改變它開始與小寫：

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

Answer 2

你就不能申報它作爲一個實例變量？

爲了符合最佳實踐，實例變量應該是private，其名稱應該符合標準的Java命名約定，以小寫字母開頭;例如

private Amostra sample;