Reading the java files from the folder

Question

I have developed an application that reads files from the folder chosen by the user. It displays how many lines of code are in each file. I want only Java files to be shown in the file-chooser (files having .java extension). Below is my code:

 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);

             }  

I have editied also but still it is not working please advise please advise how to read only the files having .java as an extension in other words only java files from the folder ,please advise

Answer 1

You need a FilenameFilter. This should work for you:

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

Answer 2

You should look upon Filtering the list of Files in JFileChooser.

It has an example of ImageFilter.java which shows only image files in file chooser.