According to J2RE javadocs: http://docs.oracle.com/javase/7/docs/api/java/io/File.html#length()
public long length()
Returns the length of the file denoted by this abstract pathname. The return value is unspecified if this pathname denotes a directory.
So new File("path to your file").length() > 0 should do the trick. Sorry for bd previous answer. :(
