topic Re: REST API : Start an instance providing the key (not the id) in Alfresco Archive

REST API : Start an instance providing the key (not the id)

othmann — Wed, 23 Mar 2011 16:01:18 GMT

Hi everyone, First of all, congratulations for the nice work behind Activiti. I need to use the REST API to start a process instance. I chose to use the process definition key instead of the process definition id, so as to start automatically the latest version of the process. It is made clear in

Re: REST API : Start an instance providing the key (not the id)

frederikherema1 — Thu, 24 Mar 2011 07:05:08 GMT

Strange, the code does actually check if the processDefinitionKey is available. If not, the ID is mandatory:

org.activiti.rest.api.process.ProcessInstancePost:41


    String processDefinitionKey = req.getString("processDefinitionKey");
    String processDefinitionId = null;
    if (processDefinitionKey==null) {
      processDefinitionId = req.getMandatoryString(obj, "processDefinitionId");
    }

Are you sure you typed "processDefinitionKey" correct.?

Re: REST API : Start an instance providing the key (not the id)

hrabe — Thu, 24 Mar 2011 08:52:16 GMT

The problem could be

String processDefinitionKey = req.getString("processDefinitionKey");

public String getString(String param) {
    return checkString(req.getParameter(param), param, false);
}

is called on ActivitiRequest

whereas

processDefinitionId = req.getMandatoryString(obj, "processDefinitionId");

public String getMandatoryString(ActivitiRequestObject obj, String param) {
    return checkString(obj.getString(param), param, true);
}

is called on ActivitiRequestObject

Re: REST API : Start an instance providing the key (not the id)

othmann — Thu, 24 Mar 2011 09:31:01 GMT

Yes, it works when you give processDefinitionKey as a POST parameter (and not in the JSON body as written in the user guide). But the other parameters still have to be in the JSON body, which, of course, is weird.

Should I report a bug issue ?

Re: REST API : Start an instance providing the key (not the id)

frederikherema1 — Tue, 29 Mar 2011 06:48:17 GMT

Yes, go ahead

Re: REST API : Start an instance providing the key (not the id)

othmann — Tue, 29 Mar 2011 13:31:37 GMT

Done : http://jira.codehaus.org/browse/ACT-737

Re: REST API : Start an instance providing the key (not the id)

lucassouza1 — Sat, 02 Jul 2011 03:25:18 GMT

I had the same problem and it was solved adding a header content type to application/json

Re: REST API : Start an instance providing the key (not the id)

gumba — Wed, 08 Aug 2012 10:33:01 GMT

Hi Lucasousa1
I want to do the same but I keep getting error, see my code.
Could you give more tips on how did you managed to do this?
I have this code:
import org.apache.commons.io.IOUtils;
import org.apache.http.HttpHost;
import org.apache.http.HttpResponse;
import org.apache.http.auth.AuthScope;
import org.apache.http.auth.UsernamePasswordCredentials;
import org.apache.http.client.AuthCache;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.protocol.ClientContext;
import org.apache.http.entity.StringEntity;
import org.apache.http.impl.auth.BasicScheme;
import org.apache.http.impl.client.BasicAuthCache;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.protocol.BasicHttpContext;

public class RestAPI {

/**
* @param args
*/
public static void main(String[] args) {
try {
 // TODO Auto-generated method stub
 DefaultHttpClient client = new DefaultHttpClient();
 client.getCredentialsProvider().setCredentials(new AuthScope("localhost", 8080),
 new UsernamePasswordCredentials("kermit", "kermit"));

 // Create AuthCache instance
 AuthCache authCache = new BasicAuthCache();
 // Generate BASIC scheme object and add it to the local auth cache
 BasicScheme basicAuth = new BasicScheme();
 authCache.put(new HttpHost("localhost", 8080, "http"), basicAuth);

 // Add AuthCache to the execution context
 BasicHttpContext localcontext = new BasicHttpContext();
 localcontext.setAttribute(ClientContext.AUTH_CACHE, authCache);
 HttpPost postMethod = new HttpPost("http://localhost:8080/activiti-rest/service/process-instance");

 postMethod.setEntity(new StringEntity("{\"processDefinitionKey\":\"MailSender\"}", "UTF-8"));
 HttpResponse response = client.execute(postMethod, localcontext);
 System.out.println(IOUtils.toString(response.getEntity().getContent()));
 client.getConnectionManager().shutdown();
 } catch (Exception e) {
 // TODO Auto-generated catch block
 e.printStackTrace();
 }



}

}

<html>
<head>
 <title>Status page</title>
</head>
<body style="font-family: sans-serif;">
Internal Server Error
Failed to retrieve the process definition parameters
You can get technical details <a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.5.1">here</a>. 
Please continue your visit at our <a href="/">home page</a>.

</body>
</html>