Monday, 30 May 2016

BPEL Chapter 1: Hello World BPEL Project

Long ago, back in 2004/2005 when Oracle released Oracle BPEL 10.1.2 (and its predecessor the global available release of the rebranded Collaxa product) and in 2006 with the release of the first SOASuite 10.1.3, you had a Project per BPEL process. Each project was setup around the BPEL process file. Since 11g BPEL is a component in the Software Component Architecture (SCA) and a project can contain multiple BPEL components together with other components as Mediator, Rules, etc. In a later section I'll elaborate on the SCA setup, but for now I'll focus on the BPEL component. When I do I probably edit this introduction.

I had to make this introduction because using 12c we have to create a SOA Application with a SOA Project for our first BPEL process.

I assume you have installed the SOA QuickStart. If not do so, for instance with the use of the silent install. That article describes the installation of the BPM QuickStart, but for SOA QuickStart it works exactly the same, but you might want to change the home folder from c:\oracle\JDeveloper\12210_BPMQS to c:\oracle\JDeveloper\12210_SOAQS.

Then start JDeveloper from the JDeveloper home. If you used the silent install option, then you can start JDeveloper via c:\oracle\JDeveloper\12210_BPMQS\jdeveloper\jdev\bin\jdev64W.exe.

Create SOA Application

After having JDeveloper started, click on the 'New Application' link, top right. You can also use the New icon () or the File->New menu, option Application or From Gallery:
You'll get the following screen:

Choose SOA Application and click OK. This results in the following first page of the Create SOA Application wizard:
Name the application 'HelloWorld' and provide a Directory for the root folder for the application. For instance 'c:\Data\Source\HelloWorld'. And click Next.
Then provide a name for the project. For now you can use the same name as the application. The Project Directory should be adapted automatically. If not make sure it's a subfolder in the application's directory, and click Next:

In the last step of the wizard you can choose a Standard Composite (with a start component) or a Template for the composite. You could choose for a composite with a BPEL Process, but for now, let's choose an Empty Composite, since we need to create a schema first.

JDeveloper SOA Application Screen Overview

When you click finished your JDeveloper screen looks more or less like:

Top left you'll find the Project Navigator that shows the generated artefacts that you'll find in the project folder. In the middle of the left panes you'll find a Resource Navigator which enables you to edit some specific property files in the SOA Application. But we'll leave them for the moment. Bottom left you'll find two tabs, one of which is the structure pane. This one comes in handy occasionally, but we'll get into that later as well.

In the middle you'll find the Composite Designer. We'll cover it later more extensively, but for now this is the start of assembling our application. Top Right you'll find a collapsed pane for the Components. You can expand it by clicking on it:
Top right you'll find a  button to dock the pane. This will make the pane visible permanently. This is the default. This is the default, but to free up space and have a larger portion of your screen available for the designer(s), you can collapse it using the minus-icon on the same place as the Dock-button:

To add components to the application you simply drag and drop than on the appropriate pane.

Create an XML Schema

A BPEL process is exposed as a service in most cases. To do so you have to create a WSDL (WebService Definition Language) document. This is an interface contract for a service described in XML. It defines the input and output of a service and the possible operations on the service. Each possible operation needs refer to it's input and possible output message. And each message refers to the definition of that message. The message definition is done as an element in an XML Schema Definition (XSD). Although you can have it auto-generated, it's recommended to do a bottom-up definition of the contract. So let's start with the XSD.

Using the File->New->From Gallery menu choose 'XML Schema' and click OK:
Enter the details of the file: name it 'HelloWorld.xsd'. The Directory is per default the 'Schemas' folder within the project. Namespaces are important in a xsd and the wsdl, so give a proper namespace, like '' and provide a convenient prefix for it, like 'hwd':

This generates the following  xsd:
The xsd should contain an element for the request as well as the response  message. First rename the 'exampleElement' to 'helloWorldRequestMessage'. If you click on the element the name of the elememt should be highlighted. Then you can change the name by starting to type the new name. You can also bring up the properties pane and change the name there:

Change the name to helloWorldRequestMessage; I like to have elements have a proper name and in this case it's defining a request message for the HelloWorld service. I use the Java Standard Camel Case notition where elements have a lowercase first character.

It's time to extend the XSD. Since we're in the XSD editor, the component pallette is changed and contains the possible components to use in an XSD:

Drag and drop a new element from the pallette to under the helloWorldRequestMessage, until you see a line under the element and a plus-sign to the mouse-pointer:

Name the new element helloWorldResponseMessage.
In the same way add a complexType and name it HelloWorldRequestMessageType. I don't like implicit nameless complexTypes within elements. So I tend to always create named comlextypes, that I name the same as the corresponding elements, except for a UpperCase first character and the suffix 'Type'.

Then add a sequence on the helloWorldRequestMessage:

Do the same for complexType HelloWorldResponseMessageType
Then in the HelloWorldRequestMessageType add a sequence:

And in the sequence drag and drop an element called 'name'.
Do the same for HelloWorldResponseMessageType, except name the element 'greeting'.

Now we need to set a type for the elements. Right-click on the name element and choose 'Set Type' from the context menu:

In the dropdown box choose xsd:string:

You can also set the type from the properties:

Set also the greeting element to xsd:string.

Then set the helloWorldRequestMessage to the type hwd:HelloWorldRequestMessageType:

And the helloWorldResponseMessage to the type hwd:HelloWorldResponseMessageType accordingly.
After saving it, the resulting xsd shood look like:

Create the WSDL

Now we can create a WSDL based on the xsd. JDeveloper has a nice WSDL generator and editor.
The easiest way to generate or kickstart a wsdl is to drag and drop a SOAP service from the component palette:

to the Exposed Services lane on the canvas:
This opens the dialog for defining the SOAP Service. Name it HelloWorld. Then you can choose a WSDL or generate/define it from scratch based on the xsd. To do so click on the cog:

The name of the wsdl is pre-defined on the SOAP service, but you can leave the suggestion. Do yourself a favor and provide a sensible namespace. I choose 'http://xmlns.darwin-it.local/xsd/HelloWorld/HelloWorldWS'. Think of a good convention where you have a company base url (I'll get back to it later, but for now it's common convention to use an URI, that does not need, in most cases even don't, refer an actual existing internet address).
Set the the Interface type to 'Synchronous Interface' and click the green plus icon to define a message for the Input:

There you can give the message part a name, for this you can also define a convention, but there is actually no real point in doing so. So you can leave it just to the suggested 'part1'. Click on the magnifier icon and look for the HelloWorld.xsd under Project Schema Files. Select the 'helloWorldRequestMessage' and click OK:

Back in the Add Message Part dialog, click OK again:
Back in the Create WSDL dialog, you can leave the names for Port Type and Operation, to the proposed values. For this service execute is a quite proper name. But in the future it is wise to think of a proper verb that gives a proper indication of what the operation means. Later when I'll discuss WSDL's you'll find that a WSDL can hold several operations and porttypes.

For now click OK again:

And also in the Create Web Service dialog click OK again:

What results in a HelloWorldWS Service in the Composite definition:

Create the HelloWorld BPEL process

At this point we're ready to add a BPEL Process. In the component palette look for the BPEL Proces Icon:

and drag&drop it on the Components lane in the Composite canvas:

This will bring up the following dialog.

Fill in the folowing properties like:

The namespace is not really important here, you could leave it at the suggested value. It's only used internally, not exposed since we're using a pre-defined wsdl to expose the service. However you can change it to a proper value like here to identify it as a BPEL created by you/your company. This can be sensible when using tools like Oracle Enterprise Repository. But especially when you generate the wsdl by exposing the BPEL process as a SOAP service.

Click on the import 'Find Existing WSDLs' icon to bring up the following WSDL search dialog:

Here you see that you can browse for WSDLs through various channels: look into an Application Server for already deployed services, search in the SOA-MDS (more on that later) and so on. But since we have the WSDL in our project, choose for the File System

Within the project navigate to the WSDLs folder and choose the HelloWorldWS.wsdl, and click OK.
This will bring us back to the Create BPEL Process dialog. Important here is to deselect the 'Expose as a SOAP service' checkbox, since we want to reuse the already defined SOAP service, instead of having a new service generated. In the case you missed this, and a new service is generated, you can delete it easily.

Now the only thing to do, before implementing the process, is to 'wire' the HelloWorldWS SOAP Service to the BPEL Process. Do so by picking up the '>' icon and drag it over to the top  '>' icon in the BPEL Process:

You'll see that a green line appears between the start icon, that gets a green circle around it, and the possible target icons.

Implement the BPEL process

Open the BPEL designer by right clicking on the BPEL component and choose  'Edit' or  double-clicking it:

This opens the BPEL Designer with a skeleton BPEL process:

It shows a so-called 'Partner link'  to the left. There are two 'Partner Links' Lanes one on each side of the process. They're equal, the designer picks out a lane for each new Partner Link as it finds appropriate, but you can drag and drop them to the other side when it suites the drawing better. But the so-called client Partner Link is always shown left at start, and it is common to have it left.

Then you'll see two activities in the process in the main-process-scope: receiveInput  and replyOutput. The first receives the call and initiates the BPEL Process.

If you edit this activity, you'll be able to see and edit the name of the activity. It shows the input variable where the request document is stored. And very important the checkbox 'Create Instance' is checked. This means that this is the input activity that initiates a process instance. It is very important that this is the very first Receive or Pick activity in the BPEL process.

The Reply activity is the counterpart of the first Receive and is only applicable for a synchronous BPEL process. It responses to the calling Service Consumer with the contents of the outputVariable.

So in between we need to build up the contents of the outputVariable based up on the provided input.

Since we're in the BPEL Designer, you could have noticed that the Component Palette has changed. It shows the BPEL Constructs and Activities, and below those some other extension categories that I'll probably cover in a more advanced chapter:

Take the Assign activity:

and drag and drop it between the 'receiveInput' and 'replyOutput' activities:

When dragging the Assign activity, you'll notice the green add-bullets denoting the valid places where you could drop the activity. This results in:

You can right-click-and-edit or double-click the activity:

Which results in the Assign Editor. It opens on the Copy Rules tab, but first click on the General tab to edit the Name of the Assign:

Switch back to the Copy Rules Tab. On the right, locate the outputVariable and 'Expand All Child Nodes', by right-clicking it and choose the appropriate option:

Then drop the Expresion icon (the most right in the button bar) on the greeting element of the variable:

This brings up the Expression Builder:

Here choose the concat() function under the category 'String Functions' under Functions. Place the cursor between the brackets and locate the name element under the helloWorldRequestMessage element under the inputVariable.part1. Edit the expression to prefix the name with 'Hello ' and suffix it with an exclamation mark. resulting in the expression:
concat( 'Hello ', $inputVariable.part1/ns2:name,'!')

This results in:

 Here you see that an element of the inputVariable is used in a function to build up the greeting. For more complex XSD's you can add several copy rules, as many as needed, just by drag and dropping elements to their target-elements. For now, the assign is finished, so click OK.

Your process now looks like the example above. Save the process by clicking the Save or Save All, that look like the old-school floppy disks.

Fire up the Integrated Weblogic

To be able to test the BPEL process, we'll need a SOA Server. At a real-live project, a proper server installation will be provided to you and your team (preferably and presumably). This is recommended even for development to be able to do integration tests for a complex chain of services and to be able to work against enterprise databases and information systems.

But for relatively small unit tests as this Oracle provided an integrated weblogic in the SOA QuickStart topology of JDeveloper with a complete SOASuite and Service Bus. To start it choose the menu option Run->Start Server Instance (IntegratedWeblogicServer):

The first time you do this, you'll have to provide a user id for the administrator (usually weblogic) and a corresponding password (often welcome1). Provide the credentials to your liking (and remember them):

When clicking OK, a log viewer pops up at the bottom that shows the server output log of the integrated weblogic server:

Wait until the message appears:

SOA Platform is running and accepting requests. Start up took 92300 ms
IntegratedWebLogicServer startup time: 363761 ms.
[IntegratedWebLogicServer started.]

Now the SOA Suite Server is available to receive the HelloWorld Composite and do some tests.

Deploy ...

Deploying a SOA Composite is a kind of special way of deployment that differs from deploying a regular Web Application. Although you can find a deploy menu option in the Application menu of JDeveloper, this one is not suitable for SOA Composite deployments. For SOA Composite projects, you need to right-click on the project name and choose Deploy and then the name of the Project.

This starts a wizard with on the first page two options, Deploy to Application Server and Generate SAR File:

A SAR file is a so-called SOA-Archive and is used to be able to have the project deployed by an administrator to a target environment without the need of JDeveloper. Choose the option Deploy to Application Server and click Next.

In the next page, select the Overwrite any existing composite with the same revision ID checkbox, but deselect the Keep running instances after redeployment. Although this is the first deployment (so there are no existing running instances yet), after this deployment you'll find that this sort of profile is added to the deployment context menu, and not checking the Overwrite... option will cause a failure in the next deployments. But there's no need to keep existing instances running. Keep the Revision ID. Click Next.

Select the pre-defined IntegratedWeblogicServer and click Finish.

The log pane is opened on the SOA tab:

If you've done everything ok, then a BUILD SUCCESSFUL message is shown. By the way, alhough it might not be clear to you, the integrated build-tool Apache ANT is used for this.

When the BUILD SUCCESSFUL message is shown, you can switch to the Deployment tab. After building the SAR it is send to the weblogic server. If this finishes without errors you'll be able to test it.

... and test the BPEL process

Testing and monitoring the SOA Composite instances can be done using the Enterprise Manager - Fusion Middleware Control.

To open it, start a Internet Browser and navigate to http://localhost:7101/em (or the server:port where your admin-server runs extended with the URI '../em'). This should bring you to the Login page:

Use the credentials you used to start the IntegratedWeblogicServer for the first time to login.
Then the Enterprise Manager - Fusion Middleware Control landing page is opened for the Weblogic Domain

Click on the Navigator Icon to open up the Target Navigation and navigate to the composite under SOA->soa-infra->default:

Here the SOA node contains both service-bus projects and SOA Suite (soa-infra) Composite Deployments. The node Default is actually the Default partition. You can create several partitions, to catalog your deployments.

Open the HelloWorld[1.0] composite by clicking on it. Click on the Test button:

You can select a Service, Port and Operation as defined in the composite. Expand the nodes under SOAP Body, to navigate to the name input field. Fill in a nice value for name and click on Test Web Service:

After a (very) short while (dependent on the complexity of the service) the response will be shown:

Only for Synchronous services, a response message will be shown. But you can (practically) always click on the Launch Flow Trace  button to review the running, faulted or completed instance:

The flowtrace shows the different initiated components in the flow in a hierarchical way.
Here you can click on the particular components that you want to introspect. Clicking on the HelloWorldBPELProcess will open up the BPEL Flow:

If you click on the the assign activity this will show:

It might be that in your case you'll not be able to open this, or viewing the message contents. This is caused by the Audit Level of the SOA Suite that by default is set to 'Production'. Even on the SOA QuickStart...

To resolve this you'll need to go to the Common Properties of the SOA Infrastructure. You can use the Target Navigation browser to navigate to the soa-infra. But you can also use the SOA Composite to navigate to the SOA Infrastructure Common Properties:

Then use the SOA Infrastructure menu to navigate to SOA Administration -> Common Properties:

Here you can set the Audit Level to Development. Click on the Apply button to effectuate the change.

Do another test and check-out the BPEL Flow and review the message contents.


So this concludes the first part of my series BPEL. And if you bravely followed my step-by-step instructions you should be able to do some basic navigation through JDeveloper and the Enterprise Manager Fusion Middleware Control. I hope you find this entertaining, although you might already be an experienced SOA Developer. But then you probably didn't get this far...

In next articles I hope to slowly increase the level of the subjects. Coming up: invoking other services and using scopes. But probably I need to explain something about SoapUI to provide mockservices. And to deliver a more convenient way to test your services.

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