Is it advisable to return ResultSet?

Question

Hi,
I am studying one java code to enhance its performance.
In that code,
there is one method called getAccountingLines() that returns ResultSet.
This method is called at different 8 places in the entire code.
// pseudo code for getAccountingLine method
private ResultSet getAccountingLines(String fsDocCD, String fsDocDeptCd, String fsDocId, String fsDocVersNo, String fsTableName, String fsVendCustCd)
ResultSet lrs = null;
StringBuffer loQuery = new StringBuffer(1440);
Form the Select query(large in size) and assign it to loQuery.
try
lrs = (ResultSet)( moSession.getResultSetBySQL (loQuery.toString(),
moSession.getDataServerForObject(fsTableName),100));
return lrs
catch (Exception E)
System.err.println("Error Executing Query for getting the Accounting Lines information");
return null;
// code where getAccounting method is called
private void processStmtDetVectors(Vector fvStmtDetPABL, Vector fvStmtDetCC, Vector fvStmtDetPYM,
boolean fbCanAddToHist, R_ADImpl foAd, String fsBillLocCd,boolean fbCanAddToDet,String fsStmtType) throws Exception
ResultSet loResSet = null;
try
loResSet = getAccountingLines(lsDocCd,lsDocDeptCd,lsDocId,lsDocVersNo,"RE_DOC_ACTG",lsVendCustCd);
if (loResSet != null)
catch(Exception e)
finally
if (loResSet!=null )
loResSet.close();
Now my question is :
Is the reference of ResultSet instance(lrs) of getAccountingLine() method is closed with ResultSet instance(loResSet) of callee method(processStmtDetVectors) closed.
What I understand from above is references of ResultSet instance(lrs) of getAccountingLine() method are not closed with ResultSet instance(loResSet) of callee method(processStmtDetVectors) closed. If it remains open, it can creat memory problems.
Is it advisable to return ResultSet?
I think, method should return String (Query Statement) and at the place where method called, query should fire.
Let me know whether my understanding regarding this is true or not.
Anything else if any one can add to this, please let me know.
This will be very helpful to me.
Thanks in advance,
Deepalee

Answer 1

As a general rule, no, there is nothing wrong with returning a ResultSet (I do it myself all the time). You just have to be careful not to access it after the Statement or Connection go out of scope or are closed. If you do, you're liable to get a NullPointerException or something equally nasty.