Is there a way to dynamically determine the number of out parameters for a server side procedure?

Question

Hi,
Below is a helper method used for calling a server-side function which loops through the inbound bindVars parameter to populate the function's IN parameters. Is there a way to dynamically determine the IN/OUT parameters based on the procedure name in the stmt parameter? No members of the CallableStatement class seemed promising, but the getParameterMetaData() method in the PreparedStatement class seemed like it could be helpful lead. However, I have not found any detailed descriptions (yet) of how to use it.
protected Object callStoredFunction(int sqlReturnType, String stmt,
  Object[] bindVars) {
  CallableStatement st = null;
  try {
  // 1. Create a JDBC CallabledStatement 
  st = getDBTransaction().createCallableStatement(
  "begin ? := "+stmt+";end;",0);
  // 2. Register the first bind variable for the return value
  st.registerOutParameter(1, sqlReturnType);
  if (bindVars != null) {
  // 3. Loop over values for the bind variables passed in, if any
  for (int z = 0; z < bindVars.length; z++) {
  // 4. Set the value of user-supplied bind vars in the stmt
  st.setObject(z + 2, bindVars[z]);
  // 5. Set the value of user-supplied bind vars in the stmt
  st.executeUpdate();
  // 6. Return the value of the first bind variable
  return st.getObject(1);
  catch (SQLException e) {
  throw new JboException(e);
  finally {
  if (st != null) {
  try {
  // 7. Close the statement
  st.close();
  catch (SQLException e) {}
James

Answer 1

The PreparedStatement.getParameterMetaData() object is exactly what you need for this task.
Once you have the ParameterMetaData you can ask it how many parameters are present and which mode they are. The parameters are numbered from 1 to n and you can use ParameterMetaData.getParameterMode(1); to get the mode of the 1st parameter. The modes are defined as static values in the ParameterMetaData object. Check out the doc at http://docs.oracle.com/javase/7/docs/api/java/sql/ParameterMetaData.html
Timo