Oracle StoredProcedure is returning null values

[nitin88]

Hi I am trying to execute stored procedures using Spring JDBC.
Here's the SP class

     class IncrementExtraBalanceStoredProcedure extends StoredProcedure {

		/**
		 * @param jdbcTemplate
		 * @param procedureName
		 */
		public IncrementExtraBalanceStoredProcedure(JdbcTemplate jdbcTemplate, String procedureName) {
			super(jdbcTemplate, procedureName);
			declareParameter(new SqlOutParameter(O_RETURN_CODE, Types.INTEGER));
			declareParameter(new SqlParameter(P_NUMEC, Types.INTEGER));
			declareParameter(new SqlParameter(P_GBYTES, Types.INTEGER));
			compile();
		}

		/**
		 * @param inputBean
		 * @return resultObjects
		 */
		public Map<String, Object> execute(RateLimitLogBean inputBean) {
			Map<String,Object> sqlMap = new HashMap<String,Object>();
			sqlMap.put(P_NUMEC, inputBean.getNumec());
			sqlMap.put(P_GBYTES,  inputBean.getGb());
			return super.execute(sqlMap);
		}

	}

I am calling this class from this method.

     public int incrementExtraBalance(RateLimitLogBean inputBean) {
		IncrementExtraBalanceStoredProcedure procedure = new IncrementExtraBalanceStoredProcedure(this.jdbcTemplate, "RATELIMIT_OWN.increment_extra_balance");
		Map<String, Object> resultMap = procedure.execute(inputBean);
		if (!StringUtils.isEmpty(resultMap)) {
			return ((Integer) resultMap.get(O_RETURN_CODE)).intValue();
		}
		return -1;
	}

But I am getting null value as O_RETURN_CODE. It's supposed to return 0
The execution of this function from Toad - Oracle Db

>var z number

>exec RATELIMIT_OWN.unlimit_contract (0123,:z)

>print z

*I got 0 as output in Toad.*

Why I am getting null value as return from Java code (no sql exceptions).
Is there anything wrong with code?

Update:
native calls returning proper output

    public void unlimitContract(RateLimitLogBean inputBean, boolean load) throws SQLException {
		String sql = "{call RATELIMIT_OWN.unlimit_contract (?,?)}";
		CallableStatement callableStatement = this.dataSource.getConnection().prepareCall(sql);
		callableStatement.setInt(1, 0123);
		callableStatement.registerOutParameter(2, java.sql.Types.INTEGER);
		 
		callableStatement.executeUpdate();
		 
		int resultCode = callableStatement.getInt(2);
	}

SQL SP

CREATE OR REPLACE PROCEDURE RATELIMIT_OWN.increment_extra_balance (p_numec IN  NUMBER,
  p_gbytes            IN    NUMBER,
  o_return_code    OUT NUMBER)
AS
   
   message            logs.errormsg%TYPE;
   
BEGIN

  update balance set extrabalance=extrabalance+(p_gbytes*1073741824),limited=0 WHERE numec = p_numec;
  
  IF SQL%ROWCOUNT = 0
  THEN
    o_return_code:=1;
  ELSE
    o_return_code:=0;
    message := 'Cops added ' || p_gbytes || ' gb extra volume';
    INSERT INTO logs (logid, eventid, origin, numec, VALUE, errormsg) VALUES (seq_log.NEXTVAL, 'NEXTRAROV', 'increment_extra_balance', p_numec, p_gbytes, message);
  END IF;

   commit;
  
  EXCEPTION
    WHEN OTHERS
    THEN
      o_return_code := SQLCODE;
      ROLLBACK;  
        
END;
/