wro4j-core/src/main/java/ro/isdc/wro/util/WroUtil.java
public static File createTempFile(final String extension) {
    try {
      final String fileName = String.format("wro4j-%s.%s", UUID.randomUUID().toString(), extension);
      final File file = new File(createTempDirectory(), fileName);
      file.createNewFile();
      return file;
    } catch (final IOException e) {
      throw WroRuntimeException.wrap(e);
    }
  }
public static File createTempFile(final String extension) {
    try {
      final String fileName = String.format("wro4j-%s.%s", UUID.randomUUID().toString(), extension);
      final File file = new File(createTempDirectory(), fileName);
      file.createNewFile();
      return file;
    } catch (final IOException e) {
      throw WroRuntimeException.wrap(e);
    }
  }
Creates a temp file which has a certain extension.

@param extension
of the created temp file.