1.1

}
public Object[] getOutParameters() {
throw new AssertionError("this procedure has no out parameters");
}
public Object[] getNextResultRow(int resultSetNumber)
throws InterruptedException {
// this procedure deals with only result set number 1
assert resultSetNumber == 1;
IncomingResultSet[] inSets = context.getIncomingResultSets(1);
Object[] lesserRow = null;
Comparator cmp = getComparator();
IncomingResultSet setWithLeastRow = null;
for (IncomingResultSet inSet : inSets) {
Object[] nextRow = inSet.waitPeekRow(); // blocks until row is
available
if (nextRow == IncomingResultSet.END_OF_RESULTS) {
// no more rows in this incoming results
continue;
}
// find the least row so far
if (lesserRow == null || cmp.compare(nextRow, lesserRow) <= 0) {
lesserRow = nextRow;
setWithLeastRow = inSet;
}
}
if (setWithLeastRow != null) {
// consume the lesserRow by removing lesserRow from the incoming
result set
Object[] takeRow = setWithLeastRow.takeRow();
assert takeRow == lesserRow;
}
// if lesserRow is null, then there are no more rows in any incoming
results
return lesserRow;
}
public boolean getMoreResults(int nextResultSetNumber) {
return false; // only one result set
}
public void close() {
this.context = null;
}
/** Return an appropriate Comparator for sorting the rows */
private Comparator<Object[]> getComparator() {
// return an appropriate comparator for the rows
throw new UnsupportedOperationException("comparator not implemented");
}
}
165
Using the Custom Result Processor API