Method create

src/main/java/gate/persist/SerialDataStore.java:143–173

Create a new data store. This tries to create a directory in the local file system. If the directory already exists and is non-empty, or is a file, or cannot be created, PersistenceException is thrown.

()

    * a file, or cannot be created, PersistenceException is thrown.
    */
  @Override
  public void create()
  throws PersistenceException {
    if(storageDir == null)
      throw new PersistenceException("null storage directory: cannot create");

    if(! storageDir.exists()) { // if doesn't exist create it
      
      if(! storageDir.mkdir())
        throw new
          PersistenceException("cannot create directory " + storageDir);
    } else { // must be empty
      String[] existingFiles = filterIgnoredFileNames(storageDir.list());
      if(! (existingFiles == null || existingFiles.length == 0) )
        throw new PersistenceException(
          "directory "+ storageDir +" is not empty: cannot use for data store"
        );
    }

    // dump the version file
    try {
      File versionFile = getVersionFile();
      OutputStreamWriter osw = new OutputStreamWriter(
        new FileOutputStream(versionFile)
      );
      osw.write(versionNumber + Strings.getNl());
      osw.close();
    } catch(IOException e) {
      throw new PersistenceException("couldn't write version file: " + e);
    }
  } // create()

  /** The name of the version file */
  private static String versionFileName = "__GATE_SerialDataStore__";