向文件末尾添加内容

  1. BufferedWriter out = null;
  2. try {
  3.       out = new BufferedWriter(new FileWriter(”filename”, true));
  4.       out.write(”aString”);
  5. } catch (IOException e) {
  6.       // error processing code
  7. } finally {
  8.     if (out != null) {
  9.         out.close();
  10.     }
  11. }

列出文件和目录

  1. File dir = new File("directoryName");
  2. String[] children = dir.list();
  3. if (children == null) {
  4.     // Either dir does not exist or is not a directory
  5. } else {
  6.     for (int i=0; i < children.length; i++) {
  7.         // Get filename of file or directory
  8.         String filename = children[i];
  9.     }
  10. }
  11. // It is also possible to filter the list of returned files.
  12. // This example does not return any files that start with `.'.
  13. FilenameFilter filter = new FilenameFilter() {
  14.     public boolean accept(File dir, String name) {
  15.         return !name.startsWith(".");
  16.     }
  17. };
  18. children = dir.list(filter);
  19. // The list of files can also be retrieved as File objects
  20. File[] files = dir.listFiles();
  21. // This filter only returns directories
  22. FileFilter fileFilter = new FileFilter() {
  23.     public boolean accept(File file) {
  24.         return file.isDirectory();
  25.     }
  26. };
  27. files = dir.listFiles(fileFilter);