org.apache.poi.hssf.eventusermodel.HSSFRequest Maven / Gradle / Ivy
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package org.apache.poi.hssf.eventusermodel;
import java.util.HashMap;
import java.util.List;
import java.util.ArrayList;
import java.util.Map;
import org.apache.poi.hssf.record.Record;
import org.apache.poi.hssf.record.RecordFactory;
/**
* An HSSFRequest object should be constructed registering an instance or multiple
* instances of HSSFListener with each Record.sid you wish to listen for.
*
* @see org.apache.poi.hssf.eventusermodel.HSSFEventFactory
* @see org.apache.poi.hssf.eventusermodel.HSSFListener
* @see org.apache.poi.hssf.eventusermodel.HSSFUserException
*/
public class HSSFRequest {
private final Map> _records;
/** Creates a new instance of HSSFRequest */
public HSSFRequest() {
_records = new HashMap>(50); // most folks won't listen for too many of these
}
/**
* add an event listener for a particular record type. The trick is you have to know
* what the records are for or just start with our examples and build on them. Alternatively,
* you CAN call addListenerForAllRecords and you'll receive ALL record events in one listener,
* but if you like to squeeze every last byte of efficiency out of life you my not like this.
* (its sure as heck what I plan to do)
*
* @see #addListenerForAllRecords(HSSFListener)
*
* @param lsnr for the event
* @param sid identifier for the record type this is the .sid static member on the individual records
* for example req.addListener(myListener, BOFRecord.sid)
*/
public void addListener(HSSFListener lsnr, short sid) {
List list = _records.get(Short.valueOf(sid));
if (list == null) {
list = new ArrayList(1); // probably most people will use one listener
_records.put(Short.valueOf(sid), list);
}
list.add(lsnr);
}
/**
* This is the equivalent of calling addListener(myListener, sid) for EVERY
* record in the org.apache.poi.hssf.record package. This is for lazy
* people like me. You can call this more than once with more than one listener, but
* that seems like a bad thing to do from a practice-perspective unless you have a
* compelling reason to do so (like maybe you send the event two places or log it or
* something?).
*
* @param lsnr a single listener to associate with ALL records
*/
public void addListenerForAllRecords(HSSFListener lsnr) {
short[] rectypes = RecordFactory.getAllKnownRecordSIDs();
for (int k = 0; k < rectypes.length; k++) {
addListener(lsnr, rectypes[k]);
}
}
/**
* Called by HSSFEventFactory, passes the Record to each listener associated with
* a record.sid.
*
* Exception and return value added 2002-04-19 by Carey Sublette
*
* @return numeric user-specified result code. If zero continue processing.
* @throws HSSFUserException User exception condition
*/
protected short processRecord(Record rec) throws HSSFUserException {
Object obj = _records.get(Short.valueOf(rec.getSid()));
short userCode = 0;
if (obj != null) {
List listeners = (List) obj;
for (int k = 0; k < listeners.size(); k++) {
Object listenObj = listeners.get(k);
if (listenObj instanceof AbortableHSSFListener) {
AbortableHSSFListener listener = (AbortableHSSFListener) listenObj;
userCode = listener.abortableProcessRecord(rec);
if (userCode != 0)
break;
} else {
HSSFListener listener = (HSSFListener) listenObj;
listener.processRecord(rec);
}
}
}
return userCode;
}
}