Sunday 28 April 2013

Generate a Web Service Client from a WSDL using Jdeveloper


I recently had to code one half of an automated service which would connect to a Webservice and retrieve data based on the parameters sent. It needed to be converted back to XML from a Java Object and stored in a local directory. It wasn’t an easy one to start with as it involved security/authentication certificates which although I have had exposure to with OID/Single Sign on and external Tiers in the E-Business Suite, I had never really got to grips with, after this little project I sure have.

The other half which I didn’t have to code consisted of java stored procedures in an Oracle database which loaded the XML file , validated it and then loaded it into some target tables. This was all to remove the manual process of downloading and uploading the file which needed down by an end user daily. I’ve played around with this on my own time and will expand on this tutorial of sorts in the future to cover that.
First thing is first, download the latest version of Jdeveloper, I’ve used 11g Release 2

Finding an example to use isn’t that hard, there are plenty of websites which list publicly available webservices.

http://www.xmethods.net
http://www.webservicex.net/ws/default.aspx

I’ve decided to use the stock quote example , the wsdl can be found at the below
http://www.restfulwebservices.net/wcf/StockQuoteService.svc?wsdl

That’s enough links for now !!!
Open up Jdeveloper





Choose New Application > Custom Application
Enter an Application Name


Select Next
Enter Project Name

Click Finish
Right Click the newly created project and select New.

Under Categories, ‘Select Web Services’
Under Items, ‘Web Service Client and Proxy’

 
 
For this it was left as default. JAX-WS Style


Select Next
It is here you paste in the address of the WSDL.

Copy WSDL into Project.
 
Click Next to go through the other options but for me I choose to Finish.
Jdeveloper will start importing in the required packages and classes and building the client.



You should now have something like the above in your project.
The basic code for the client is ready


Thanks to my excellent naming it looks like I’ve ended up with quite the mouthful for the client file , oh dear, never mind.
StockQuoteService defines a Java interface that represents the service. It defines a method that returns a stub for the service.
IStockQuoteService defines a Java interface that represents the methods of the Web Service. These methods will match up with the elements in the WSDL

The client as its created first creates an instance of the StockQuoteService class which implements the interface which represents the service. It then retrieves a stub that represents the remote Web Service.

This is all well and good but we haven’t actually interacted with the webservice yet to get back anything meaningful.

To do this you should use the below code
Create JAXB object instance to accept the response

      StockQuote stockQuote = new StockQuote();
Populate the JAXB instance by calling the interface to the Webservice with a value, in this case  the ticker symbol for Oracle
      stockQuote = iStockQuoteService.getStockQuote("ORCL");
What you then do with the object is very much open, you can take individual elements and print them to a text file after converting them to a string. I choose to output the whole object as an XML file by using the JAXB Marshaller class which is used to convert java objects to XML 
I added the below to my imports for the class BasicHttpBinding_IStockQuoteServiceClient

import javax.xml.bind.JAXBContext;
import javax.xml.bind.JAXBException;
import javax.xml.bind.Marshaller;

I added this entry to the StockQuote.java above the class definition to allow the Marsharller to have a root reference

@XmlRootElement(name="StockQuote")

The last part was to write the code to convert the object and output to the console, you can see below the code and result of running this.

This was just a very basic attempt at interacting with a webservice that I thought I’d write up, hopefully it gets some people started and over a few bumps when using jdeveloper.

 

 

Wednesday 17 April 2013

Oracle Database 10g Administrator Certified Professional

Well today as part of a large Oracle event at my work in which you were able to go and sit some Oracle exams i took the 10g Admin II exam and passed only missing a few questions.

The amount of work to get ready for it was a lot more than i expected. I've been doing quite a few development projects of late which have been taking up a lot of time as I rediscover the wondeful world of Java and learn webservices.

Luckily i was able to cram in enough revision and only missed 3 questions. The timing couldn't be better. I've a backlog of posts to make about creating java clients for webservices, deploying a pl/sql procedure as a webservice on weblogic and posting the useful topics I've made notes on while revising.

And did I mention i've a new baby due next week, let the fun begin

Friday 12 April 2013

: ORA-24010: QUEUE APPLSYS.WF_NOTIFICATION_OUT does not exist

We had this error in a test environment where they were trying to run a few things through workflow mailer in the Ebusiness Suite. It was quite a recent clone but for the most part, I prefer not to have workflow on without reason in test systems without the over-ride email address set.

I've been in the position in the past where a junior DBA has cloned, forgotten to do this or not reset the workflow accounts and workflow has sent out emails to customers and also connected to the live account and moved emails into the discard folder.

There was a direct hit for the error on Metalink [ID 886377.1] which was tried but didnt resolve the issue. On checking then if the workflow queue existed under applsys it wasnt found so it was time to rebuild the queue.

The below should bring back 3 objects under applsys, table, queue and synonym.


select owner, object_type, status
from dba_objects
where object_name='WF_NOTIFICATION_OUT';



I've rebuilt the out queue hundreds of times and its usually down to issues in the INBOX with spamming mail killing the workflow IMAP connection to the account and it 'hangs'. Another popular one is customers replying to a workflow email or copying the address in on a reply to their manager. Nothing is sure to stop the workflow mailer from working as quick.

To rebuild the out queue automatically you would run the below.

select distinct  tablespace_name
from dba_indexes,dba_queues
where index_name like 'WF%N1'
and table_name=queue_table
and name like 'WF%';

connect to SQL*Plus as applmgr user

@$FND_TOP/patch/115/sql/wfntfqup.sql APPS APPSPW APPLSYS

this rebuilds the queue, now to rebuild the index.

connect as applsys , replace question marks with value from first select.

CREATE INDEX WF_NOTIFICATION_OUT_N1
ON WF_NOTIFICATION_OUT(CORRID)
STORAGE (INITIAL 1M NEXT 1M MINEXTENTS 1 MAXEXTENTS 2147483645 PCTINCREASE 0)
TABLESPACE ?????????????;

If you want to rebuild it yourself as I did manually you will want to follow Metalink Note [400493.1]