Help understanding referencing

Question

Hi,
I wrote a small test harness to call a web service (although this question is not related to web services) and I noticed something happening that I didnt understand. I believe it may have something to do with pass by value although this is really just a guess. In the code snippet below the id number is always empty, what I was trying to do was set some of the values and then only change the ID number as its the only thing that changes (getIDNumber() just returns an ID from the database):
//Create input/output objects
            SystemRecordInput input = new SystemRecordInput();
            SystemRecordInputData inputData = new SystemRecordInputData();
            SystemRecordOutput output = null;
            //Set up input data
            inputData.setCallingPassword(password);
            inputData.setRecordType("HTML");
            inputData.setSystemTime("?");
            /*here is the problem I was facing, setting this object into
              container bean seems to dereference it*/
            input.setServiceInput(inputData);           
            //loop for no of iterations
            for(int i = 0; i < iterations; i++) {
                //Setting the ID number now does not set the id number of the object I am
                //passing into the web service
                inputData.setIDNumber(getIDNumber());
                ID = inputData.getIDNumber();
                try {
                    startTimeMillis = new java.util.Date().getTime();
                    output = service.loadSystemDetail(input);
                    endTimeMillis = new java.util.Date().getTime();
                    auditID = output.getStandardOutput().getAuditID();
                    statusID = output.getStandardOutput().getStatusID();
                    System.out.println("Writing result for ID # " + ID);
                    writeResult(startTimeMillis, endTimeMillis, nhs, statusID, auditID, statusID.equals("0") ? "success" : "remote failure");
                } catch (Exception e) {
                    endTimeMillis = new java.util.Date().getTime();
                    writeResult(startTimeMillis, endTimeMillis, ID, statusID, auditID, e.getMessage());
     This code works when I change it to this (comments added into code snippet):
//Create input/output objects
            SystemRecordInput input = new SystemRecordInput();
            SystemRecordInputData inputData = new SystemRecordInputData();
            SystemRecordOutput output = null;
            //Set up input data
            inputData.setCallingPassword(password);
            inputData.setRecordType("HTML");
            inputData.setSystemTime("?");
            //loop for no of iterations
            for(int i = 0; i < iterations; i++) {               
                inputData.setIDNumber(getIDNumber());
                //This line below when moved here does keep the reference
                //and the value is passed into the web service call
                input.setServiceInput(inputData);
                ID = inputData.getIDNumber();
                try {
                    startTimeMillis = new java.util.Date().getTime();
                    output = service.loadSystemDetail(input);
                    endTimeMillis = new java.util.Date().getTime();
                    auditID = output.getStandardOutput().getAuditID();
                    statusID = output.getStandardOutput().getStatusID();
                    System.out.println("Writing result for ID # " + ID);
                    writeResult(startTimeMillis, endTimeMillis, nhs, statusID, auditID, statusID.equals("0") ? "success" : "remote failure");
                } catch (Exception e) {
                    endTimeMillis = new java.util.Date().getTime();
                    writeResult(startTimeMillis, endTimeMillis, ID, statusID, auditID, e.getMessage());
            }I did solve the problem, but could someone explain what is happening in the examples? I hope I have provided enough information for this to be answered.
Thanks
Edited by: nda on Aug 19, 2009 12:52 AM

Answer 1

Hi Winston,
There is no reason for using the time method, I just didnt know about System.currentTimeMillis().
SystemRecordInput is bean that holds a couple of objects (only one is shown here), its a wrapper for the webservice inputs. The ID is a unique id to get a record from a remote system, this is just a test harness to try out the service.
The only thing I couldnt understand is why after setting the SystemRecordInputData object into the SystemRecord outside of the loop setting the ID in the loop and then invoking the service does not include the ID number.
If the ID number is set into the SystemRecordInputData first within the loop and then the SystemRecordInputData is set into the SystemRecordInput the ID value is passed across in the web service call.
This doesnt have anything do with the web service, its more do with passing one object into another object and then trying to use the reference to that object that was passed in..... if that makes sense?