Can anyone please explain me the difference between the class mediator and custom handler in detail, what use cases these two mediators are used
Existing handlers are executed first in the request flow. Mediation sequences are executed after that. But if you write a custom handler, you can put it after mediation sequences as well, because mediation sequences are also executed by a handler (APIManagerExtensionHandler). So if you place your handler after APIManagerExtensionHandler, it will execute after mediation sequences.
One main difference between a class mediator and a handler is that handlers are executed in both request flow and response flow, and you can write 2 logics for those 2 cases in the same handler. But a class mediator has only a single section (i.e. mediate() method). When you engage a class mediator in a sequence, you can decide if you want to put it in request flow or response flow, or in both.
If your logic is not complex, you can use existing mediators instead of writing a class mediator. In that case, you don't need to write any java code.
You may read this as well.
Related
I have a class mediator in sequence which will have list of requests.
Now I need to iterate the list of request and send it to a defined end point.
Please advise.
You can use Call Mediator to call multiple web services in a single sequence.
See Call Mediator for details.
You can do iterate your messages using Iterate mediator.
See Iterate Mediator for details.
Thanks
Currently I am developing a ws with OSB using JDeveloper 11.
I have a simple web service, which calls an external SOAP service.
My composite.xml file:
Operations of my BPEL Soap service
Operations of remote SOAP Service
BPEL Component
I have few questions regarding the current development strategy. How shall I add new operations to my BPEL SOAP? I added a new method (getCompanyDetails()) by editing ApusBPELProcess.xsd (added new request and response types) and ApusBPELProcess.wsdl (added new operation, message and etc). Is this the correct way for adding new operations?
Now I can call only one method of the remote SOAP service by using an "Invoke" component from BPEL constructs.
My BPEL design:
How can I call bind a method from my BPEL SOap (1) to a method from remote service (2) ? For example: when client calls method process from my BPEL Soap (1), I want to do some validation on input parameters and then call getServiceCompanies from remote SOAP (2). And so when client calls another method from BPEL Soap (1) I want to call some other methods on remote SOAP (2).
Will be very thankful if someone can show me a diagram, with required components. Because I read about "Mediator" components, but I don't know how to use them in my current situation.
Thanks in advance.
One option is, You can use Pick activity that can have multiple onMessage branches for each operation exposed by your BPEL service.
Similarly, Invoke activity has an option to select the operation of the Remote SOAP service that you need to call.
So your composite would look like Pick activity with an OnMessage branch with BPELoperation1 selected, then logic to do validation and then invoke with remoteoperation1 selcted.And another onMEssage branch with BPELoperation2 selected, logic to do validations and invoke with remoteoperation2 selected.
I found a solution with Mediator component. Maybe it will help someone.
Ok, I added a Mediator component between my exposed service and remote service. Mediator component will do request routing and data transformation between these two services. For each method in my exposed service I added a BPEL process to the other endpoint of Mediator (I will do some method specific validation/other logic inside these BPEL processes).
My final composite.xml:
Methods of my exposed service
Mediator
The remote service what I call
Inside Mediator component I do routing and transformation. For each method of my exposed service (1) I have a routing rule in Mediator (2).
Mediator component rules:
4a, 4b - Methods of my exposed service
4c - button for adding new routing rule
4d - button for adding transformation rule (generally you will have a pair of transformation rules for a method - request/response)
Transformation files are .xsl files that do information convertion between two endpoints.
My .xsl files:
Content of a .xsl file:
Here I am doing iteration through the response data (for-each component).
And finally inside of each BPEL process I have an "Invoke" component (5) which calls the appropriate method on the remote service.
Hope it will someone. Good luck!
Anybody would please through some light on difference between call and send mediator and what use cases these two mediators are used.
Send mediator - used to send messages out of Synapse to some endpoint. Then the response is returned to the OutSequence where you can send it back to the client
Use cases - When you only need to send a message to one back end and return the response back to the client.
Call mediator - Also used to send messages out of the Synapse to some endpoint, but the response does not come to the OutSequence. When we send a request using the call mediator, the response will arrive to the mediator that is placed right after the call mediator.So this will allow us to specify all the service invocations one after the other in a chain within a single sequence
Use cases - Service chaining. i.e.- Vehicle license renewal service
Another characteristic is that the callout mediator is blocking, send mediator and call mediator are not blocking. This answer is in regards to WSO2 versions until 4.8.0
I am confused with the above two mediators. What is the difference between Call out mediator and send mediator in wso2ESB mediators?
Actually callout mediator makes a blocking call, it cannot use the default non-blocking http/s transports based on Java NIO. But the send mediator makes aynchronous call for services. This is the basic difference between them. For more about those you can refer the documentation;
http://docs.wso2.org/display/ESB470/Mediators
Additionally to callout mediator WSO2 ESB team has introduced another brand new mediator to serve blocking call to Backend. "Call Mediator" is very similar to the Callout Mediator, which performs a blocking external service invocation during mediation. Unlike the Callout mediator, the Call mediator leverages the non-blocking transports for much greater performance.
Will the aggregator mediator work in insequence ?
I have a splitter which will split the messages to JMS queue. I have another proxy service which should collect the messages and aggregate it.
I have kept the aggregator in insequence. Am I logically correct ?
Regards
Guru
#gnanagurus
Message aggregation cannot be done in the inSequence without having a iterate mediator placed in inSequence.
There is a correlation between the splitting and the aggregation.
You can only aggregate messages which are split using the iterate mediator or cloned using clone mediator within the same Proxy service.
If you can provide me more information on your scenario, I can help you further.