Invoking Stored Procedure with OUT Parameter

Question

I am calling a stored procedure that has a "out" parameter of PL/SQL type (table of varchar2) through toplink API. My procedure executes, performs the updates successfully, but I can not obtain the value of the out parameter. Is the approach followed below incorrect? I could not figure out by looking into examples provided in the documentation:
http://download.oracle.com/docs/cd/B25221_04/web.1013/b25386/building_and_using_application_services009.htm#BCFEFAHC
Java function is given below:
public List removeFromAutoupdSched( List srNumbers, String userName)
if (srNumbers == null || srNumbers.size() == 0)
return null;
List result = null;
try
//Example Stored procedure call with an output parameter
DatabaseLogin login = m_dbSess.getLogin();
Connection conn = (Connection) (java.sql.Connection)login.connectToDatasource(null);
oracle.sql.ArrayDescriptor arrDesc = new oracle.sql.ArrayDescriptor("AUTOUPD_SRLIST_T", conn);
oracle.sql.ARRAY srARR = new oracle.sql.ARRAY(arrDesc, conn, srNumbers.toArray());
StoredProcedureCall procCall = new StoredProcedureCall();
procCall.setProcedureName("SEW_AUTOUPD.PURGE_AUTOUPD_SCHEDULE");
procCall.addNamedArgumentValue("excludeSRlist", srARR);
procCall.addNamedArgumentValue("exclude_by", userName);
procCall.addNamedOutputArgument(
"excludeSR_srlist_status",
"excludeSR_srlist_status",
OracleTypes.ARRAY,
"AUTOUPD_SRLIST_ERRS_T"
ValueReadQuery vq = new ValueReadQuery();
vq.setCall(procCall);
oracle.sql.ARRAY srResultARR = (oracle.sql.ARRAY)m_dbSess.executeQuery(vq);
if (srResultARR != null)
String[] msgs = (String[])srResultARR.getArray();
if (msgs.length > 0)
result = Arrays.asList(msgs);
Iterator iter = result.iterator();
while (iter.hasNext())
System.out.println("msg = " + iter.next());
return result;
catch (Exception exc)
throw new RuntimeException(exc);
PL/SQL Type
create or replace TYPE autoupd_srlist_errs_t IS TABLE OF VARCHAR2(150);
Sample procedure called by toplink:
PROCEDURE purge_autoupd_schedule(
excludeSRlist autoupd_srlist_t,
exclude_by VARCHAR2,
excludeSR_srlist_status OUT NOCOPY autoupd_srlist_errs_t)
IS
pkg sew_log.pkg_name%TYPE default upper('sew_autoupd');
prc sew_log.prc_name%TYPE default upper('purge_autoupd_schedule(excludeSRlist, exclude_by)');
srno NUMBER;
-- cnt NUMBER := 0;
exclude_status VARCHAR2(150);
err_prefix VARCHAR2(50) := 'Unable to exclude from autoupdate, ';
BEGIN
FOR i IN excludeSRlist.FIRST..excludeSRlist.LAST
LOOP
BEGIN
srno := excludeSRlist(i);
-- Update actn_taken column in autoupd_schedule before doing delete.
UPDATE autoupd_schedule SET actn_taken='Removed by engineer', UPD_TIME=systimestamp
WHERE sr_no = srno and engr_itsid = exclude_by;
-- Add SR to exclusion list.
INSERT INTO autoupd_exclude(sr_no, exclude_by, exclude_time) VALUES (srno, exclude_by, systimestamp);
exclude_status := 'Item ' || i || ' - SR ' || srno || ' - ' || 'Excluded from autoupdate.';
excludeSR_srlist_status(i) := exclude_status;
EXCEPTION
WHEN others THEN
-- Add SR to excludeSR_fail if previous steps occurred okay.
-- cnt := cnt +1;
exclude_status := 'Item ' || i || ' - SR ' || srno || ' - ' || err_prefix || substr(sqlerrm,12);
excludeSR_srlist_status(i) := exclude_status;
END;
END LOOP;
EXCEPTION
WHEN others THEN
sew_logger.log(
code => substr(sqlerrm,1,9),
msg => substr(sqlerrm,12),
pkg => pkg,
prc => prc
END;
Any help is appreciated.

Answer 1

What happens if you run the stored procedure through pure jdbc (without TopLink)?
I tried a simple example that worked for me:
//defined type in the db
CREATE TYPE "TEST"."VAR_LIST" AS  TABLE OF VARCHAR2(150)
//defined stored procedure in the db
CREATE OR REPLACE  PROCEDURE "TEST"."VAR_LIST_IN_OUT"  (
VARS_IN VAR_LIST,
VARS_OUT OUT NOCOPY VAR_LIST
as
begin
  VARS_OUT := VAR_LIST();
  FOR i IN VARS_IN.FIRST..VARS_IN.LAST LOOP
    VARS_OUT.EXTEND;
    VARS_OUT(i) := CONCAT(VARS_IN(i), '_BLAH');
  END LOOP;
end;
// Java code
StoredProcedureCall call = new StoredProcedureCall();
call.setProcedureName("VAR_LIST_IN_OUT");
Connection conn = (Connection) ((oracle.toplink.internal.sessions.AbstractSession)getSession()).getAccessor().getConnection();
oracle.sql.ArrayDescriptor arrDesc = new oracle.sql.ArrayDescriptor("VAR_LIST", conn);
oracle.sql.ARRAY srARR = new oracle.sql.ARRAY(arrDesc, conn, new String[]{"A1", "A2", "A3"});
call.addNamedArgumentValue("VARS_IN", srARR);
call.addNamedOutputArgument("VARS_OUT", "VARS_OUT", Types.ARRAY, "VAR_LIST");
ValueReadQuery query = new ValueReadQuery();
query.setCall(call);
Object result = getSession().executeQuery(query);
Object[] array = (Object[])((java.sql.Array)result).getArray();
for(int i=0; i<array.length; i++) {
    System.out.println(array);
// System.out:
[TopLink Finest]: 2008.04.25 15:37:16.687--DatabaseSessionImpl(3491657)--Thread(Thread[main,5,main])--Execute query ValueReadQuery()
[TopLink Fine]: 2008.04.25 15:37:16.703--DatabaseSessionImpl(3491657)--Connection(29118152)--Thread(Thread[main,5,main])--BEGIN VAR_LIST_IN_OUT(VARS_IN=>?, VARS_OUT=>?); END;
     bind => [oracle.sql.ARRAY@323274, => VARS_OUT] (There is no English translation for this message.)
A1_BLAH
A2_BLAH
A3_BLAH
My stored procedure didn't work (on Oracle 9 db) without output collection initialization: VARS_OUT := VAR_LIST(); and extending: VARS_OUT.EXTEND.