Thursday, 5 January 2012

How to pass the queue name dynamically to MQ Adapter

Requirement: To pass the queue name dynamically to MQ Adapter from a variable


Use-case: I have a process that is required to enqueue the data in one of the two MQs at runtime based on certain condition using single MQ Adapter. So if the condition is true the data is to be enqueued in queue A else in queue B. However, the payload schema remains the same in both the queues. (using SOA Suite 11.1.1.3)


Solution: Use the jca.mq.ISpec.EnqueueMsgToQ property appearing in the Properties tab of Invoke Activity. Assign the value of the property to the variable name which contains the MQ name.
Passing Queue Name from a variable


Setting the value to this variable will allow you to set the queue name dynamically in the process or from outside the process.


Advantage: MQ Adapter can be loosely coupled and kept in a separate composite which can be called by any caller composite. Also a single MQ Adapter can be used for en-queuing to multiple queues, 

Wednesday, July 13, 2011

Pass multiple parameters, dynamic query in Pure SQL in Database Adapter

I came across a case in which I was required to pass the bind parameters values on the fly. The values of parameters were not fixed and hence I couldn't define all of them as the bind parameters. Hence in the search of the solution I wasted considerable time until I was directed to see this great solution. The solution was fantastic and I customized it further to make it work with SOA Suite11g. This can be further extended with Joins to do wonders as required. 


Use Case : I want the salaries of all the employees whose first names I'd pass at run time. Hence it can be single name or n names coming as parameters. The very simple query, as it comes to our mind, would be


SELECT SALARY FROM EMPLOYEES WHERE F_NAME IN (?) 
Where ? is the argument that is passed dynamically. 


However, the same query doesn't work in DB adapter for any combination passed dynamically such as ('NEERAJ', 'JACOB') or "('NEERAJ', 'JACOB')" or 'NEERAJ', 'JACOB' for the adapter tries to interpret the incoming argument as a bind parameter and not SQL string.


Solution :  If the parameters can be passed as a result of an inner query the problem can be solved. The following query uses CONNECT BY LEVEL clause to separate the individual parameter values separated by a and represents them as individual result row.


SELECT SALARY FROM EMPLOYEES WHERE F_NAME 
IN (WITH BIND_PARAM_LIST AS
(SELECT #val FROM dual)
SELECT SUBSTR(#val1, (decode(LEVEL, 1, 0, instr(#val2, ':', 1, LEVEL -1)) + 1), (decode(instr(#val3, ':', 1, LEVEL) -1, -1, LENGTH(#val4), instr(#val5, ':', 1, LEVEL) -1)) -(decode(LEVEL, 1, 0, instr(#val6, ':', 1, LEVEL -1)) + 1) + 1) a
FROM 
BIND_PARAM_LIST CONNECT BY LEVEL <=
(SELECT(LENGTH(#val7) -LENGTH(REPLACE(#val8, ':', NULL)))
FROM 
BIND_PARAM_LIST) + 1)


To understand the query one needs to be familiar with the CONNECT BY clause which is used for hierarchical queries. If you simply do 


SELECT LEVEL FROM DUAL CONNECT BY LEVEL <=5, it prints 1 to 5 in each row like

LEVEL
=====
1
2
3
4
5


The same logic is being used in the above query to separate the various F_Names. It just sub-strings the incoming string NEERAJ:JACOB:ROBERT, wise for each LEVEL to feed the result in the IN clause as 


NEERAJ
JACOB
ROBERT


Usage : Just add this query in the DB Adapter. Be careful to use # instead of ? as in 11g the bind variable name can be defined as #bind_variable, in our case #val1, #val2 ... #val8. Also you'll have to assign the same input string to these multiple vals. The val variables get exposed as input parameters while assigning and can be assigned as 'NEERAJ:JACOB:ROBERT'(your parameter list). You can use any other separator too e.g. ; instead of : by customizing the query a bit. 


Just deploy the project and it is done. The same thing can also be achieved by using query-database() function as described here.
   
      

Monday, June 27, 2011

Delete Data from MDS - Single Files

In case an artefact is wrongly published into MDS, it can be deleted from the MDS using 2 ways.
  1. Deleting the entire folder
  2. Deleting the Selective Files
This post details about the latter.
A file can be deleted from the MDS using Weblogic Scripting Tool. However, in upgraded versions of AIA (11g PS3 onwards), this is available  through UpdateMetaDataDP.xml also, very much the same way as we update the artefacts in MDS. To delete a file from MDS follow the following steps.


1. Run WLST command from <MW_HOME>/oracle_common/bin. Note there is same command available in Weblogic Server home directory too but MDS related commands can be accessed through wlst.sh/exe residing in oracle_common_home only 
    $ cd $MW_HOME/oracle_common/common/bin
  $ wlst.sh

2. Type the connect command to connect to soa_server1 or WLS_SOA1 depending on where your soa-infra is running
   $ connect('weblogic', 'welcome1', 't3://localhost:8001')

3. Once it is connected, delete The undesired file by typing the following command (Note the path starting from /apps)
  $ deleteMetadata(application='soa-infra',server='soa_server1',docs='/apps/AIAMetaData/AIAComponents/ApplicationConnectorServiceLibrary/Generic.wsdl')


You can use asterisk(*) to specify more than one files e.g. to delete all files with names starting with Gen use 
deleteMetadata(application='soa-infra',server='soa_server1',docs='/apps/AIAMetaData/AIAComponents/ApplicationConnectorServiceLibrary/Gen*.wsdl')
Exception:
You may get the following exception
MDS-91002: MDS Application runtime MBean for "soa-infra" is not available. "deleteMetadata" operation failure.
Solution:
Verify that your soa-infra is up and running and is on the same server to which you are connected through WLST.


Happy Learning...

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