The Imixs RestClient

The Imixs-RestClient is a helper class to establish connections to a Rest Service Endpoint. The client can be used for general HTTP communication and also for the Imxis-Rest API.

Core Methods

The RestClient provides the following GET and POST core methods:

Method Description
get(url) Gets the content of a GET request from a Rest Service URI Endpoint. I case of an error the method throws a RestAPIException.
get(url) Posts a String data object with a specific Content-Type to a Rest URI Endpoint. This method can be used to simulate different post scenarios.
registerRequestFilter(RequestFilter) adds a request filter

Imixs Rest-API Data Methods

The following methods can be used to GET and POST Imxis Workflow Data

Method Description
setServiceEndpoint(String) builds the serviceEndpoint based on a given URI
setEncoding(String) defines the encoding used for post requests
setRequestProperty(String, String) Set a single header request property.
post(String, String, String) Posts a String data object with a specific Content-Type to a Rest Service UR Endpoint
postCollection(url, DocumentCollection) POST MEHTHOD for a document collection
get(url) Gets the content of a GET request from a Rest Service URI Endpoint.

The following example shows how to post a workitem:

ItemCollection workitem = new ItemCollection().model(MODEL_VERSION).task(1000).event(10);
workitem.replaceItemValue("_subject", "some data");
// create client restCLient = 
// process workitem
String resultData = + "workflow/workitem",
                   MediaType.APPLICATION_XML,	MediaType.APPLICATION_XML);
List<ItemCollection> result = XMLDataCollectionAdapter.readCollection(resultData.getBytes());

The next example shows how to request the tasklist of a user:

// create client restCLient = 
String resultData = restCLient.get(BASE_URL + "workflow/tasklist/creator/admin");
List<ItemCollection> result = XMLDataCollectionAdapter.readCollection(resultData.getBytes());

RequestFilter & Authentication

The Imixs-RestClient supports also custom “RequestFilters”. A Requestfilter implements the interface and can be used to handle a HTTP Request.

public class MyFilter implements RequestFilter {	
	public void filter(HttpURLConnection connection) throws IOException {
		// your code goes here...

There a several Request filters available to be used for authentication:

  • BasicAuthenticator - for a BASIC authentication
  • FormAuthenticator - for a form based authentication with a JSESSION cookie
  • JWTAuthenticator - for authentication based on JSON Web Tokens

The following example shows how to use a BASIC authentication filter:

RestClient restClient = new RestClient();
// create a default basic authenticator
BasicAuthenticator basicAuth = new BasicAuthenticator("myuser","mypassword");
// register the authenticator

The Imixs Melman Project

The Imixs Melman Project provides a more convenient component library to interact with the Imixs-Workflow Rest API. The project is agnostic from an Imixs-Workflow Implementation and can be used in a microservice architecture. The components are based on Java JAX-RS and JAX-B.