Connector-call switch serialization from json to xml on wildfly


during the last training I stumbled over a strange behavior of connector and output-mapping:

A process variable is serialized in json in the start form. After passing a connector which modifies an attribute of the tweet (see task ‘Flownode-Zähler holen’), the tweet is serialized in xml.

This happens on my wildfly-distro (7.5.2-ee), running java 8 on windows 10:

  JAVA: "C:\Tools\java\jdk-1.8.74\bin\java"

  JAVA_OPTS: " -Xms512m -Xmx768m -XX:MetaspaceSize=128M -XX:MaxMetaspaceSize=256m -Djboss.modules.system.pkgs=org.jboss.byteman"


14:09:31,740 INFO  [org.jboss.modules] (main) JBoss Modules version 1.5.1.Final
14:09:31,963 INFO  [org.jboss.msc] (main) JBoss MSC version 1.2.6.Final
14:09:32,048 INFO  [] (MSC service thread 1-6) WFLYSRV0049: WildFly Full 10.0.0.Final (WildFly Core 2.0.10.Final) starting

The Junit-Test asserting the serialization data format is fine. (see line 80-81 of InMemeoryH2Test).

But running this on my local wildfly, the task-form for ‘Nachricht prüfen’ is empty and the cockpit shows the tweet object serialized in xml:

If I skip the connector task, the tweet is json (as expected),

You can find the complete eclipse project on github: and play around with it for yourself.

What’s the reason for this behavior?

Is it a bug?

Or did I miss something?

Cheers, Ingo