Tag Archives: rest

Using “curl” to request the Imixs-Workflow Rest API

The command line tool ‘curl’ is useful in cases when you just want to check some REST APIs from a console. You can find a lot of information about how to use curl on curl.haxx.se.

If you want to test the Imixs Rest API you need in most cases a basic authentification against the Workflow Server. This is an example how to send username/password along with a GET request:

curl --user admin:mypassword http://localhost:8080/imixs-microservice/workflow/worklist

This examples returns the worklist for the User ‘admin’ from a Imixs-Workflow Rest Service running on localhost port 8080.

If you don’t specify the media type Imixs-Workflow will return an HTML output. You can see this also in your Browser. But Imixs-Workflow also supports the media types JSON and XML. To request the same URL in JSON you can add a Header parameter like this:

curl --user admin:mypassword -H "Accept: application/json" http://localhost:8080/imixs-microservice/workflow/worklist

or if you want to get the same response in XML format:

curl --user admin:mypassword -H "Accept: application/xml" http://localhost:8080/imixs-microservice/workflow/worklist

If you know the UniqueID of a workitem, which is included in the worklist result you can also request a single Workitem from the Imixs-Workflow. See the following curl example to request a workitem in JSON format:

curl --user admin:adminadmin -H "Accept: application/json" http://localhost:8080/imixs-microservice/workflow/workitem/14b65352f58-259f4f9b

This example returns the content of the Workitem with the UniqueID ’14b65352f58-259f4f9b’. You can also restrict the result to a subset of properties when you add the query parameter ‘items’:

curl --user admin:adminadmin -H "Accept: application/json" http://localhost:8080/imixs-microservice/workflow/workitem/14b65352f58-259f4f9b?items=txtname;$processid

See the Imixs-Workflow RestAPI for more information.

If you want to test what is possible with Imixs-Workflow REST API and curl you can try the Imixs-Microservice. Imixs-Microservice provides a full featured Workflow System based on a REST API. Imixs-Microservice also supports Docker so you do not need to install a Application Server by your self.

Rest Service and the HTTPServletReqeust Object

Today I got a strange problem with my REST service which needs a HttpServletRequest object to perform the RemoteUser name.

First I injected the HttpServletRequest as a field into my RestService-Class

....
@Path("/")
@Produces({ "text/html", "application/xml", "application/json" })
@Stateless
public class SystemRestService {
 ...   
	@javax.ws.rs.core.Context
	private static HttpServletRequest servletRequest;
.....

This works fine on my local glassfish server 3.1.1. But after I deployed this into my productive environment (glassfish 3.1) the field ‘servletRequest’ was always null.

The problem here is that injecting the HttpServletRequest into an instance field can become very soon stale. The solution is to annotating a method parameter to assure that the request object is obtained in connection to processing a request.

... 	
@GET
	@Path("/profile.json")
	@Produces("application/json")
	public String getUserByID(@QueryParam("uid") String user,
			@QueryParam("items") String items,@Context HttpServletRequest servletRequest) {
.....

See also this discussion on the coderanch:

http://www.coderanch.com/t/510941/Web-Services/java/Print-Client-IP#2649412