/**
* Retrieve a list of sets that satisfy the specified criteria
*
* @return a Map object containing "sets" Iterator object (contains <setSpec/> XML Strings) as
* well as an optional resumptionMap Map.
* @throws OAIInternalServerError signals an http status code 500 problem
*/
public Map listSets() throws NoSetHierarchyException, OAIInternalServerError {
StatementResultSet stmtRs = null;
if (setQuery == null) {
if (sets.size() == 0) {
throw new NoSetHierarchyException();
}
Map<String, Object> listSetsMap = new HashMap<String, Object>();
listSetsMap.put("sets", sets.iterator());
return listSetsMap;
} else {
purge(); // clean out old resumptionTokens
Map<String, Object> listSetsMap = new HashMap<String, Object>();
List<String> sets = new ArrayList<String>();
try {
LOGGER.debug(setQuery);
/* Get some records from your database */
stmtRs = new StatementResultSet(setQuery);
stmtRs.last();
int numRows = stmtRs.getRow();
stmtRs.beforeFirst();
int count;
/* load the sets ArrayLists. */
for (count = 0; count < maxListSize && stmtRs.next(); ++count) {
/* Use the RecordFactory to extract header/set pairs for each item */
Map<String, Object> nativeItem = stmtRs.getColumnValues();
sets.add(getSetXML(nativeItem));
LOGGER.debug("JDBCOAICatalog.listSets: adding an entry");
}
/* decide if you're done */
if (count < numRows) {
String resumptionId = getResumptionId();
/**
* *************************************************************** Note that storing the
* ResultSet in the resumptionResult means the token can't be reused.
* ***************************************************************
*/
resumptionResults.put(resumptionId, stmtRs);
/**
* *************************************************************** Construct the
* resumptionToken String however you see fit.
* ***************************************************************
*/
StringBuilder resumptionTokenSb = new StringBuilder();
resumptionTokenSb.append(resumptionId);
resumptionTokenSb.append("!");
resumptionTokenSb.append(Integer.toString(count));
resumptionTokenSb.append("!");
resumptionTokenSb.append(Integer.toString(numRows));
/**
* *************************************************************** Use the following line
* if you wish to include the optional resumptionToken attributes in the response.
* Otherwise, use the line after it that I've commented out.
* ***************************************************************
*/
listSetsMap.put(
"resumptionMap", getResumptionMap(resumptionTokenSb.toString(), numRows, 0));
} else {
stmtRs.close();
stmtRs = null;
}
} catch (SQLException e) {
if (stmtRs != null) {
try {
stmtRs.close();
} catch (SQLException e1) {
e1.printStackTrace();
}
}
LOGGER.error("An Exception occured", e);
throw new OAIInternalServerError(e.getMessage());
}
listSetsMap.put("sets", sets.iterator());
return listSetsMap;
}
}
/**
* Retrieve a list of records that satisfy the specified criteria. Note, though, that unlike the
* other OAI verb type methods implemented here, both of the listRecords methods are already
* implemented in AbstractCatalog rather than abstracted. This is because it is possible to
* implement ListRecords as a combination of ListIdentifiers and GetRecord combinations.
* Nevertheless, I suggest that you override both the AbstractCatalog.listRecords methods here
* since it will probably improve the performance if you create the response in one fell swoop
* rather than construct it one GetRecord at a time.
*
* @param from beginning date using the proper granularity
* @param until ending date using the proper granularity
* @param set the set name or null if no such limit is requested
* @param metadataPrefix the OAI metadataPrefix or null if no such limit is requested
* @return a Map object containing entries for a "records" Iterator object (containing XML
* <record/> Strings) and an optional "resumptionMap" Map.
* @throws OAIInternalServerError signals an http status code 500 problem
* @throws CannotDisseminateFormatException the metadataPrefix isn't supported by the item.
*/
public Map listRecords(String from, String until, String set, String metadataPrefix)
throws CannotDisseminateFormatException, NoItemsMatchException, OAIInternalServerError {
purge(); // clean out old resumptionTokens
Map<String, Object> listRecordsMap = new HashMap<String, Object>();
List<String> records = new ArrayList<String>();
StatementResultSet stmtRs = null;
try {
stmtRs = new StatementResultSet(populateRangeQuery(from, until, set));
stmtRs.last();
int numRows = stmtRs.getRow();
if (numRows == 0) {
throw new NoItemsMatchException();
}
stmtRs.beforeFirst();
int count;
/* load the records ArrayList */
for (count = 0; count < maxListSize && stmtRs.next(); ++count) {
Map<String, Object> nativeItem = stmtRs.getColumnValues();
String record = constructRecord(nativeItem, metadataPrefix);
records.add(record);
}
/* decide if you're done */
if (count < numRows) {
String resumptionId = getResumptionId();
resumptionResults.put(resumptionId, stmtRs);
/**
* *************************************************************** Construct the
* resumptionToken String however you see fit.
* ***************************************************************
*/
StringBuilder resumptionTokenSb = new StringBuilder();
resumptionTokenSb.append(resumptionId);
resumptionTokenSb.append("!");
resumptionTokenSb.append(Integer.toString(count));
resumptionTokenSb.append("!");
resumptionTokenSb.append(Integer.toString(numRows));
resumptionTokenSb.append("!");
resumptionTokenSb.append(metadataPrefix);
/**
* *************************************************************** Use the following line if
* you wish to include the optional resumptionToken attributes in the response. Otherwise,
* use the line after it that I've commented out.
* ***************************************************************
*/
listRecordsMap.put(
"resumptionMap", getResumptionMap(resumptionTokenSb.toString(), numRows, 0));
} else {
stmtRs.close();
stmtRs = null;
}
} catch (SQLException e) {
if (stmtRs != null) {
try {
stmtRs.close();
} catch (SQLException e1) {
e1.printStackTrace();
}
}
LOGGER.error("An Exception occured", e);
throw new OAIInternalServerError(e.getMessage());
}
listRecordsMap.put("records", records.iterator());
return listRecordsMap;
}