从文件夹中读取Java文件

Question

我开发了一个应用程序，可以从用户选择的文件夹中读取文件。它显示每个文件中有多少行代码。我只希望Java文件显示在文件选择器（扩展名为.java的文件）中。下面是我的代码：

 public static void main(String[] args) throws FileNotFoundException {

        JFileChooser chooser = new JFileChooser();
        chooser.setCurrentDirectory(new java.io.File("C:" + File.separator));
        chooser.setDialogTitle("FILES ALONG WITH LINE NUMBERS");
        chooser.setFileSelectionMode(JFileChooser.DIRECTORIES_ONLY);
        chooser.setAcceptAllFileFilterUsed(false);
                if (chooser.showOpenDialog(null) == JFileChooser.APPROVE_OPTION)
        {      Map<String, Integer> result = new HashMap<String, Integer>();
             File directory = new File(chooser.getSelectedFile().getAbsolutePath()); 
             int totalLineCount = 0;
             File[] files = directory.listFiles(new FilenameFilter(){
                  @Override
                  public boolean accept(File dir, String name) {
                    return name.matches("\\*\\.java");
                  }
                }
   );
              for (File file : files)
            {
                if (file.isFile())
                {    Scanner scanner = new Scanner(new FileReader(file));
                    int lineCount = 0;
                     try
                    { for (lineCount = 0; scanner.nextLine() != null; lineCount++) ;
                          } catch (NoSuchElementException e)
                    {   result.put(file.getName(), lineCount);
                    totalLineCount += lineCount;  
                                    }


                } }
              System.out.println("*****************************************");
              System.out.println("FILE NAME FOLLOWED BY LOC");
              System.out.println("*****************************************");

            for (Map.Entry<String, Integer> entry : result.entrySet())
            {   System.out.println(entry.getKey() + " ==> " + entry.getValue());
            }
            System.out.println("*****************************************");
            System.out.println("SUM OF FILES SCANNED ==>"+"\t"+result.size()); 
            System.out.println("SUM OF ALL THE LINES ==>"+"\t"+ totalLineCount);

             }

我也进行了编辑，但是仍然无法正常工作，请告知请告知如何仅读取扩展名为.java的文件，换句话说，请仅从文件夹中读取java文件，请告知

Answer 1

您需要一个FilenameFilter。这应该为您工作：

FilenameFilter javaFileFilter= new FilenameFilter() {  
  @Override
  public boolean accept(File logDir, String name) {
    return name.endsWith(".java")
  }
};