public static boolean isValidFile(RandomAccessFile raf) {
try {
raf.seek(0);
while (raf.getFilePointer() < maxScan) {
boolean found = raf.searchForward(matcher, maxScan); // look in first 16K
if (!found) return false;
raf.skipBytes(7); // will be positioned on byte 0 of indicator section
int edition = raf.read(); // read at byte 8
if (edition == 2) return true;
}
} catch (IOException e) {
return false;
}
return false;
}
public boolean hasNext() throws IOException {
if (lastPos >= raf.length()) return false;
if (repeatPos > 0) {
if (nextRepeating()) // this has created a new repeatRecord
return true;
} else {
repeatRecord = null;
repeatBms = null;
// fall through to new record
}
boolean more;
long stop = 0;
while (true) { // scan until we get a GRIB-2 or more == false
raf.seek(lastPos);
more = raf.searchForward(matcher, -1); // will scan to end for a 'GRIB' string
if (!more) break;
stop = raf.getFilePointer();
// see if its GRIB-2
raf.skipBytes(7);
int edition = raf.read();
if (edition == 2) break;
lastPos = raf.getFilePointer(); // not edition 2 ! just skip it !!
}
if (more) {
int sizeHeader =
(int) (stop - lastPos); // wmo headers are embedded between records in some idd streams
// if (sizeHeader > 30) sizeHeader = 30;
header = new byte[sizeHeader];
startPos = stop - sizeHeader;
raf.seek(startPos);
raf.read(header);
}
if (debug) System.out.println(" more " + more + " at " + startPos + " lastPos " + lastPos);
return more;
}