WSO2 ESB DataMapper mediator

Question

I'm getting the below error when trying to transform a JSON input to another JSON format using WSO2 ESB DataMapper mediator.

Here, I'm trying to do a very basic level transformation & appreciate if someone could help me to figure out the issue.

[2016-12-22 10:20:15,674] ERROR - ResvsAPI DataMapper mediator : mapping failed
Error while reading input stream. Script engine unable to execute the script javax.script.ScriptException: ReferenceError: "map_S_root_S_root" is not defined in <eval> at line number 1
    at org.wso2.carbon.mediator.datamapper.engine.input.readers.JSONInputReader.read(JSONInputReader.java:62)
    at org.wso2.carbon.mediator.datamapper.engine.input.InputBuilder.buildInputModel(InputBuilder.java:59)
    at org.wso2.carbon.mediator.datamapper.engine.core.mapper.MappingHandler.doMap(MappingHandler.java:67)
    at org.wso2.carbon.mediator.datamapper.DataMapperMediator.transform(DataMapperMediator.java:306)
    at org.wso2.carbon.mediator.datamapper.DataMapperMediator.mediate(DataMapperMediator.java:256)
    at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:97)
    at org.apache.synapse.mediators.AbstractListMediator.mediate(AbstractListMediator.java:59)
    at org.apache.synapse.mediators.base.SequenceMediator.mediate(SequenceMediator.java:158)
    at org.apache.synapse.rest.Resource.process(Resource.java:343)
    at org.apache.synapse.rest.API.process(API.java:399)
    at org.apache.synapse.rest.RESTRequestHandler.apiProcess(RESTRequestHandler.java:123)
    at org.apache.synapse.rest.RESTRequestHandler.dispatchToAPI(RESTRequestHandler.java:101)
    at org.apache.synapse.rest.RESTRequestHandler.process(RESTRequestHandler.java:69)
    at org.apache.synapse.core.axis2.Axis2SynapseEnvironment.injectMessage(Axis2SynapseEnvironment.java:304)
    at org.apache.synapse.core.axis2.SynapseMessageReceiver.receive(SynapseMessageReceiver.java:75)
    at org.apache.axis2.engine.AxisEngine.receive(AxisEngine.java:180)
    at org.apache.synapse.transport.passthru.ServerWorker.processNonEntityEnclosingRESTHandler(ServerWorker.java:325)
    at org.apache.synapse.transport.passthru.ServerWorker.processEntityEnclosingRequest(ServerWorker.java:371)
    at org.apache.synapse.transport.passthru.ServerWorker.run(ServerWorker.java:151)
    at org.apache.axis2.transport.base.threads.NativeWorkerPool$1.run(NativeWorkerPool.java:172)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

Answer 1

This can be due to an error in the input-output mapping configuration. Can you please provide a screenshot of the mapping UI view and the contents of the mapping configuration file (.dmc file) *You can find the mapping configuration inside Registry viewer tab in WSO2 ESB Management Console.