REST API - Obtaining the list of processes/variables for a process

[dragos.snk]

Hello.

I need to integrate a stand-along jBPM 6 running on Tomcat (persistence through an Oracle db) with an external system; one of the required actions is to start processes from the external system.

In order to do this, I need to:

1. present the user with the list of available process definitions in jBPM (to select which one to start)

2. present the user with the list of variables he needs to fill in order to start the selected process

For item 1, I could try to use JaxbCommandsRequest with get-process-ids command (available in 6.0.1 Final from what I've seen), through a [POST] /runtime/{deploymentId}/execute - but how would I know all the deploymentIds?.

For item 2 - didn't found anything, it seems like no command is available for that.

Note that the external system has no knowledge on the existing deployments/processes in jBPM - those can be dynamically updated by another jBPM user/admin through the console, so I cannot rely on my user to know/provide the deployment id, process id or process variables - I need to provide those for the user from jBPM.

Any idea on how to accomplish it?

Dragos Sinca

[jaysynerzip]

For the item 1 you can use the below rest api to get the deploymentIds

/rest/deployment

[swiderski.maciej]

and for the second one please file jira to be added in the next version as I see it as very valuable information, that should be part of the get process definition operation that instead of returning simple process ids, it should provide more information such as process name, version, deployment id, variables (names and types). Such data are already available in UI so should be exposed on remote apis as well

HTH

[jaysynerzip]

Seems we have already a Jira for this.

[JBPM-4178] REST API Enhancement to retrieve all process definitions - JBoss Issue Tracker

[dragos.snk]

Thank you, i missed the /rest/deployment command

Did a test today, the /rest/deployment functions properly, but /runtime/{deploymentId}/execute with GetProcessIDs command fails - added a comment on the Jira issue you mentioned, it seems it was never supported.

[jaysynerzip]

Great.

Yeah right. if that works then we will have different workaround to get the list of processes by passing the deployment id until the feature of getting the list of processes without deployment id has been implemented.

[jaysynerzip]

Hi Dragos,

             Can you please tell me the steps how you are executing the /runtime/{deploymentId}/execute with GetProcessIDs command and what error you are getting?

[dragos.snk]

See sample code below:

public class RestClient {

  public static void main(String[] args) throws IOException, JAXBException, XMLStreamException {

    String user = "krisv";

    String password = "krisv";

      GetProcessIdsCommand command = new GetProcessIdsCommand();

      JaxbCommandsRequest request = new JaxbCommandsRequest("org.jbpm.example:async-examples:1.0", command);

      request.setDeploymentId("org.jbpm.example:async-examples:1.0");

      JAXBContext jaxbRequest = JAXBContext.newInstance(JaxbCommandsRequest.class);

      Marshaller jaxbMarshaller = jaxbRequest.createMarshaller();

      URL url = new URL("http://localhost:8080/jbpm-console/rest/runtime/org.jbpm.example:async-examples:1.0/execute");

     HttpURLConnection connection = (HttpURLConnection) url.openConnection();

     String authString = user + ":" + password;

     byte[] authEncBytes = Base64.encodeBase64(authString.getBytes());

     String authStringEnc = new String(authEncBytes);

     connection.setRequestProperty("Authorization", "Basic " + authStringEnc);

     connection.setRequestMethod("POST");

     connection.setDoOutput(true);

     connection.setRequestProperty("Accept", "application/xml");

     connection.setRequestProperty("Content-Type", "application/xml");

        OutputStream os = connection.getOutputStream();

        jaxbMarshaller.marshal(request, os);

        os.flush();

        os.close();

       if (connection.getResponseCode() != 200) {

            throw new RuntimeException("Failed : HTTP error code : " + connection.getResponseCode());

       }

  //get the response from the server

  BufferedReader br = new BufferedReader(new InputStreamReader((connection.getInputStream())));

  String output;

  String xmlOutput = "";

  System.out.println("Output from Server .... \n");

  while ((output = br.readLine()) != null) {

       System.out.println(output);

       xmlOutput += output;

  }

        JAXBContext jaxbContext = JAXBContext.newInstance(JaxbCommandResponse .class);

        Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();

        JaxbCommandResponse instance = (JaxbCommandResponse ) jaxbUnmarshaller.unmarshal(new ByteArrayInputStream(xmlOutput.getBytes()));

        connection.disconnect();

  }

}

The response received from the jBPM (instead of a serialized JaxbCommandResponse with process ids):

<?xml version="1.0" encoding="UTF-8" standalone="yes"?><command-response><deployment-id>org.jbpm.example:async-examples:1.0</deployment-id><exception index="0"><command-name>GetProcessIdsCommand</command-name><message>IllegalStateException thrown with message 'String should be handled but is not in JaxbCommandsResponse!'</message></exception></command-response>

A new Jira issue was created for that - [JBPM-4312] REST API - GetProcessIDsCommand does not work - JBoss Issue Tracker

[jaysynerzip]

HI Dragos,

               Thanks for the detailed reply.

But I already figured out how to do this . I am doing in the below way and also I fixed the issue which is causing the exception. Basically the List<String> type was missing in the JaxbCommandResponse.

public class SimpleRestClient

{

    public static void main( String[] args ) throws MalformedURLException

    {

        String deploymentId = "org.jbpm:IntegrationTests:1.0";

        URL appUrl = new URL("http://localhost:8080/jbpm-console/");

        String user = "admin";

        String password = "admin";

        RemoteRestRuntimeFactory restSessionFactory = new RemoteRestRuntimeFactory(deploymentId, appUrl, user, password);

        RemoteRuntimeEngine engine = restSessionFactory.newRuntimeEngine();    

        KieSession ksession = engine.getKieSession();

        GetProcessIdsCommand getProcessIdsCommand = new GetProcessIdsCommand();

        //ksession.execute(getProcessInstancesCommand);

        List<String> processIds =  ksession.execute(getProcessIdsCommand);

        System.out.println("The list of process ids"+processIds);

        for(String pid : processIds){

            System.out.println("Process Id: "+pid);

        }

    }  

}

This is the output.

The list of process ids[TestPojos5, TestClient, TestPojos4, TestPojos3, TestPojos2, TestTypes, UseInvoice]

Process Id: TestPojos5

Process Id: TestClient

Process Id: TestPojos4

Process Id: TestPojos3

Process Id: TestPojos2

Process Id: TestTypes

Process Id: UseInvoice

Thanks again.

[marccbr]

I am trying to run http://localhost:8080/jbpm-console/rest/deployment but I am getting the following error;

Could not find MessageBodyWriter for response object of type: java.util.ArrayList of media type: application/xml

Any ideas on what could be causing this?  I have the latest jBPM 6.0.1 Final build.

[jaysynerzip]

Set the Accept header as application/json and it will work.

[marccbr]

That did it.  Thank you, I was racking my brain trying to figure this out.

[jaysynerzip]

Great..

[jmiguel77]

Hi

I am using bpms 6.0.1.GA; when i invoke this url:

http://150.88.1.121:8080/business-central/rest/runtime/com.ec.mutualistapichincha:bpm-listas-negras:1.0.0/process/instance/577/variables

the response is this:

<variables><status>SUCCESS</status><url>/business-central/rest/runtime/com.ec.mutualistapichincha:bpm-listas-negras:1.0.0/process/instance/577/variables</url><variables/></variables>

this information is totally useless; i was expecting the list of variables and the data associated with it;

i am also trying to access the variables data of the process using kie-services-client 6.0.1.Final but it doesn't seem to have any method in the API to return the process variables data.

I need that info in a project i am developing and this is really stopping me

Is there any way to fix this problem ?

[chelsea2015]

Hi Jose,

I am in a similar requirement to get response back from JBPM. Could you post If you have any solution implemented for it,

Thanks in advance,