11-5 DbToJms

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Sample Practice Document for Training Evaluation http://soatraining.hpage.com

With every training session, the presentation used and a

practice document that contains step-by step instructions for

developing the sample is provided.

This document is a demo of those practice documents. Every

document starts with an Aim and then goes on to develop a

project around that. It ends after showing the project in action.

This document comes along with the code that was developed

so that the student can see the final code as well.

Aim

To poll a database and insert the data into a JMS Queue.

Create a new table called Orders in the soademo schema

create table orders (

order_id varchar2(10),

amount number,

description varchar2(100),

processed_flag char(1));

Create a composite DbToJmsDemo with an empty BPEL process (choose Define

Interface later), BPEL

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Open the BPEL component.

Drag a DB adapter on the left Partnerlink swimlane. Click Next on the welcome page.

Give name of the adapter service as PollDB

Click Next. Here you need to select the connection that represents the DB you want to

connect to from JDeveloper. We assume the soademo connection is already created.

Check out 11-2 DBAdapter Demo.docin case you need steps to create it.

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Sample Practice Document for Training Evaluation http://soatraining.hpage.comFor the JNDI name, Jdev suggests eis/DB/soademo, but as our JNDI is

eis/DB/soademoDatabase (created in 11-1 Setting up Connections for DB Adapter.doc),

modify the JNDI to the above value.

Click Next.

Select the polling option.

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Sample Practice Document for Training Evaluation http://soatraining.hpage.comSelect the orders table.

Select Order_ID as the primary key.

Reach Step 9 to choose what to do once a row is picked up. Lets say our business

requirement does not want to delete the row, merely indicate that the row has been

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Sample Practice Document for Training Evaluation http://soatraining.hpage.comprocessed, by setting the PROCESSED_FLAG to Y. In such a case, we make use of what is

called the Logical Delete.

In a Logical delete, after picking a row, the adapter sets a value in the field which it

considers as a filterso next time when the adapter comes looking for new rows, it can

identify this row as it has that flag set.

Select the column as PROCESSED_FLAG,

Read Value as Y, (indicator that this row has been processed)

and Unread Value as N (indicator that this row has not been processed)

Reserved Value

(Optional) Enter a value to indicate that the row is reserved. This setting is useful for environments in which you have multipleadapter instances polling the same table. Each adapter instance must have its own unique reserved value. This enables contention

issues caused by two instances polling the same table to be avoided. During polling, this row is skipped.

Click next. Specify polling frequency as 20

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Click Next till you reach the finish page. Click Finish.

Drag a receive activity and connect it to the PollDBservice we just created.

The Edit Receive dialog opens up that helps to configure the Receive activity.

Name: Receive

Operation: Read (already selected)

Variable: Click the wand and create a new variable

Create Instance: Check this. This indicates that when this Receive receives an input, a

new instance of the BPEL variable is to be created (In all our previous examples, where

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Sample Practice Document for Training Evaluation http://soatraining.hpage.comwe created Synchronous and Asynchronous processes, we got receive activity by

default. You can see that all those receives had this flag set.)

Click Ok.

Add a JMS Adapter and drop it in the partnerlink swimlane on the right side.

The JMS adapter wizard shall open up. Click Next on the welcome page

1. Give name as EnqJms2. For JMS provider, select Weblogic JMS

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Sample Practice Document for Training Evaluation http://soatraining.hpage.com3. Select the application server connection that you may have created earlier. This

is required at this point because JDev will try to connect to it and get details

about available queues and topics.

4. On Adapter interface page, select Define From operation and schema (specifiedlater)

5. Select the operation as Produce message, as this JMS Adapter will producemessages

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Sample Practice Document for Training Evaluation http://soatraining.hpage.com6. Here we select the queue to which we want to send the message. Click on

Browse and select the demoTrainingQueue we created in 11-4 Setting up

Connections for JMS Adapter.doc

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7. Accept other default. Note JDeveloper has filled in the connection factory nameas eis/wls/Queue, which is perfectly fine for us. This is the default connection

factory in Weblogic, which would work for us.

8. Next we need to select the message structure. In this demo, to keep thingsimple, we just want that whatever data is coming from the db should be

enqueued in the queue. So we select the same xsd as being used by the DB

Adapter

9. Click Next and Finish.

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The BPEL shows the adapter now. Add a invoke activity and connect it to the JMS

adapter.

JMS invocation is a one way interaction. Hence there is no output variable.

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Sample Practice Document for Training Evaluation http://soatraining.hpage.comAdd an Assign activity to copy the OrderCollection from input to input of jms adapter.

As we dont need to iterate over the variable, we are using the assign activity (no need

to use transform).

The BPEL process looks as follows

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Sample Practice Document for Training Evaluation http://soatraining.hpage.comDeploy it. Test it by inserting a row in the db using a database client.

insert into orders values (1, 100,'First Order', 'N');

Commit the data.

After around 20 seconds, the row will be picked by the DB adapter, and the flag would

be set to Y.

Open the EM to find an instance. Open its trace log

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Sample Practice Document for Training Evaluation http://soatraining.hpage.comYou can see that the Db adapter PollDB called BPEL which called the JMS Adapter.

Open the BPEL process to see what is the message that has been recd from the DB

adapter

And what is the message sent to the JMS Adapter

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Sample Practice Document for Training Evaluation http://soatraining.hpage.comNow we want to confirm that this message is indeed present in the queue.

For that,

1. Open the weblogic console http://localhost:7001/console/2. In the WLS console, on the left navigation bar, expand Services | Messaging and

click on JMS Modules.

3. Click on SOAJMSModule (click on the name, not the checkbox).4. Select demoTrainingQueue5. Select Monitoring Tab6. Select checkbox next to SOAJMSModule!demoTrainingQueue and click Show

messages button

7. Click on link under ID column

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Sample Practice Document for Training Evaluation http://soatraining.hpage.com8. You should see the same message as we saw in the BPEL audit trail

9. That confirms that the message is indeed sitting in the queue.

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11-5 DbToJms