/**
* Closes the list on the system. This releases any system resources previously in use by the
* list.
*
* @exception AS400SecurityException If a security or authority error occurs.
* @exception ErrorCompletingRequestException If an error occurs before the request is completed.
* @exception InterruptedException If this thread is interrupted.
* @exception IOException If an error occurs while communicating with the system.
* @exception ObjectDoesNotExistException If the object does not exist on the system.
*/
static void closeList(AS400 system, byte[] listHandle)
throws AS400SecurityException, ErrorCompletingRequestException, InterruptedException,
IOException, ObjectDoesNotExistException {
if (listHandle == null) return;
ProgramParameter[] parameters =
new ProgramParameter[] {new ProgramParameter(listHandle), new ErrorCodeParameter()};
ProgramCall pc =
new ProgramCall(
system, "/QSYS.LIB/QGY.LIB/QGYCLST.PGM", parameters); // not a threadsafe API
if (!pc.run()) {
throw new AS400Exception(pc.getMessageList());
}
}
// Calls QGYGTLE to get the current "list information" on the progress of list-building.
private static byte[] refreshListInformation(byte[] listHandle, ProgramCall pgmCall)
throws AS400SecurityException, ErrorCompletingRequestException, InterruptedException,
IOException, ObjectDoesNotExistException {
if (pgmCall.getParameterList().length == 0) {
ProgramParameter[] parameters =
new ProgramParameter[] {
// Receiver variable, output, char(*).
new ProgramParameter(8), // minimum length is 8 bytes
// Length of receiver variable, input, binary(4).
new ProgramParameter(BinaryConverter.intToByteArray(8)),
// Request handle, input, char(4).
new ProgramParameter(listHandle),
// List information, output, char(80).
new ProgramParameter(LIST_INFO_LENGTH),
// Number of records to return, input, binary(4).
// '0' indicates: "Only the list information is returned and no actual list entries are
// returned."
new ProgramParameter(new byte[] {0x00, 0x00, 0x00, 0x00}),
// Starting record, input, binary(4).
// '0' indicates: "The list information should be returned to the caller immediately."
// '-1' indicates: "The whole list should be built before the list information is
// returned to the caller."
// new ProgramParameter(new byte[] { 0x00, 0x00, 0x00, 0x00} ),
new ProgramParameter(new byte[] {(byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF}),
// Error code, I/0, char(*).
new ErrorCodeParameter()
};
try {
pgmCall.setProgram("/QSYS.LIB/QGY.LIB/QGYGTLE.PGM", parameters);
} catch (java.beans.PropertyVetoException pve) {
} // will never happen
}
if (!pgmCall.run()) {
throw new AS400Exception(pgmCall.getMessageList());
}
return pgmCall.getParameterList()[3].getOutputData(); // the "List Information" structure
}
/**
* Calls QGYGTLE, repeatedly if necessary, to retrieve the specified number of list entries. This
* assumes that the list has previously been built on the system.
*
* @param system The system where the list has been built.
* @param listHandle The list handle for the list.
* @param lengthOfReceiverVariable The value of the "Length of receiver variable" field.
* @param number The number of list entries to return.
* @param listOffset The offset into the list (0-based).
* @param outputListInfoContainer Container in which to receive the generated "List information"
* structure. Ignored if null.
*/
static byte[] retrieveListEntries(
AS400 system,
byte[] listHandle,
int lengthOfReceiverVariable,
int number,
int listOffset,
Object[] outputListInfoContainer)
throws AS400SecurityException, ErrorCompletingRequestException, InterruptedException,
IOException, ObjectDoesNotExistException {
ProgramParameter[] parameters =
new ProgramParameter[] {
// Receiver variable, output, char(*).
new ProgramParameter(lengthOfReceiverVariable),
// Length of receiver variable, input, binary(4).
new ProgramParameter(BinaryConverter.intToByteArray(lengthOfReceiverVariable)),
// Request handle, input, char(4).
new ProgramParameter(listHandle),
// List information, output, char(80).
new ProgramParameter(LIST_INFO_LENGTH),
// Number of records to return, input, binary(4).
new ProgramParameter(BinaryConverter.intToByteArray(number)),
// Starting record, input, binary(4). (1-based: The first record is record number '1')
// '0' indicates that the list information should be returned to the caller immediately.
// The special value 0 is only allowed when the number of records to return parameter is
// zero.
// '-1' indicates that the whole list should be built before the list information is
// returned to the caller.
new ProgramParameter(
BinaryConverter.intToByteArray(listOffset == -1 ? -1 : listOffset + 1)),
// Error code, I/0, char(*).
new ErrorCodeParameter()
};
ProgramCall pc =
new ProgramCall(
system, "/QSYS.LIB/QGY.LIB/QGYGTLE.PGM", parameters); // not a threadsafe API
byte[] listInformation;
int recordsReturned;
// Call QGYGTLE, to retrieve the list entries.
// If we discover that the "receiver variable" was too small, try calling again, with
// progressively larger "receiver variable".
do {
if (pc.run()) {
listInformation = parameters[3].getOutputData();
checkListStatus(listInformation);
recordsReturned = BinaryConverter.byteArrayToInt(listInformation, 4);
} else // the call to QGYGTLE failed
{
listInformation = null;
recordsReturned = 0;
// See if the call failed because of a too-small receiver variable.
AS400Message[] messages = pc.getMessageList();
// GUI0002 means that the receiver variable was too small to hold the list.
if (!messages[0].getID().equals("GUI0002")) {
throw new AS400Exception(messages);
}
}
if (recordsReturned < number) // we didn't get as many records as we requested
{
if (listInformation != null) {
// See if we've reached the end of the list.
int totalRecords =
BinaryConverter.byteArrayToInt(
listInformation, 0); // The total number of records available in the list.
int firstRecordInReceiverVariable = BinaryConverter.byteArrayToInt(listInformation, 36);
// Note: The "First record in receiver variable" field is 1-based; that is, the first
// record is record number '1' (rather than '0').
if ((firstRecordInReceiverVariable + recordsReturned) > totalRecords) {
// All the records in the list have been returned, so don't keep requesting more.
break;
}
}
if (Trace.traceOn_)
Trace.log(
Trace.DIAGNOSTIC,
"Retrieved messages, records returned: " + recordsReturned + ", number:",
number);
if (recordsReturned < 0) { // This will never happen, but satisfy the static code analyzer.
throw new InternalErrorException(
InternalErrorException.UNKNOWN, "Records returned: " + recordsReturned);
}
// Try again, with a larger "receiver variable".
lengthOfReceiverVariable *= 1 + number / (recordsReturned + 1);
if (Trace.traceOn_)
Trace.log(Trace.DIAGNOSTIC, "Updated length: ", lengthOfReceiverVariable);
parameters[0] = new ProgramParameter(lengthOfReceiverVariable);
parameters[1] =
new ProgramParameter(BinaryConverter.intToByteArray(lengthOfReceiverVariable));
}
} while (recordsReturned < number);
// If the caller specified a non-null 'outputListInfo' parameter, copy the "list information"
// structure into it, to pass it back to the caller.
if (outputListInfoContainer != null && listInformation != null) {
outputListInfoContainer[0] = listInformation;
}
return parameters[0].getOutputData(); // the contents of the "receiver variable" field
}
