code: private static File createTempFile(
          String tempSubdirectoryName, String name) throws IOException
      {
          String tempDirName = System.getProperty("java.io.tmpdir");
          File tempSubDirectory = 
              new File(tempDirName + File.separator + tempSubdirectoryName);
          if (!tempSubDirectory.exists())
          {
              boolean createdDirectory = tempSubDirectory.mkdirs();
              if (!createdDirectory)
              {
                  throw new IOException(
                      "Could not create directory for temporary file: " + 
                       tempSubDirectory);
              }
          }
          String tempFileName = tempSubDirectory + File.separator + name;
          File tempFile = new File(tempFileName);
          return tempFile;
      }
docs: Create a file object representing the file with the given name
  in the specified subdirectory of the default "temp" directory.
  If the specified subdirectory does not exist yet, it is created.
  
  @param name The file name
  @return The file
  @throws IOException If the subdirectory can not be created