visad/src/main/java/ucar/nc2/iosp/gempak/GempakGridServiceProvider.java
public boolean isValidFile(RandomAccessFile raf) throws IOException {
    try {
      gemreader = new GempakGridReader(raf.getLocation());
      return gemreader.init(raf, false);
    } catch (Exception ioe) {
      return false;
    }
  }
public boolean isValidFile(RandomAccessFile raf) throws IOException {
    try {
      gemreader = new GempakGridReader(raf.getLocation());
      return gemreader.init(raf, false);
    } catch (Exception ioe) {
      return false;
    }
  }
Is this a valid file?

@param raf RandomAccessFile to check
@return true if a valid GEMPAK grid file
@throws IOException problem reading file