NiFi JoltTransformJSON

Question

NiFi throws an error in the JOLT processor - although the test inside the "advanced" processor interface works flawlessly!

Some flowfiles are converted without error - the majority however fail - eg:

JSON:

{
    "abc": {
        "HEADER": {
            "A": "WDD2132041A2213962",
            "B": "75268508"
        },
        "BODY": {
            "C": "OK",
            "D": "1"
        },
        "ABCDEFG": "Time[s]   |  X  |  Y  |  Z  | A/B [%] | X/Y [%] "
    }
}

JOLT:

[
  {
    "operation": "shift",
    "spec": {
      "abc": {
        "HEADER": { "*": "&" },
        "SUMMARY": { "*": "&" },
        "*": { "$": "ITEM", "@": "VAL" }
      }
    }
  }
]

Did anyone run into this kind of error before?

    2017-03-24 15:12:35,765 ERROR [Timer-Driven Process Thread-6] o.a.n.p.standard.JoltTransformJSON
java.lang.RuntimeException: Unable to load JSON object from InputStream.
        at com.bazaarvoice.jolt.JsonUtilImpl.jsonToObject(JsonUtilImpl.java:105) ~[json-utils-0.0.21.jar:0.0.21]
        at com.bazaarvoice.jolt.JsonUtils.jsonToObject(JsonUtils.java:117) ~[json-utils-0.0.21.jar:0.0.21]
        at org.apache.nifi.processors.standard.JoltTransformJSON.onTrigger(JoltTransformJSON.java:244) ~[nifi-standard-processors-1.1.0.2.1.1.0-2.jar:1.1.0.2.1.1.0-2]
        at org.apache.nifi.processor.AbstractProcessor.onTrigger(AbstractProcessor.java:27) [nifi-api-1.1.0.2.1.1.0-2.jar:1.1.0.2.1.1.0-2]
        at org.apache.nifi.controller.StandardProcessorNode.onTrigger(StandardProcessorNode.java:1099) [nifi-framework-core-1.1.0.2.1.1.0-2.jar:1.1.0.2.1.1.0-2]
        at org.apache.nifi.controller.tasks.ContinuallyRunProcessorTask.call(ContinuallyRunProcessorTask.java:136) [nifi-framework-core-1.1.0.2.1.1.0-2.jar:1.1.0.2.1.1.0-2]
        at org.apache.nifi.controller.tasks.ContinuallyRunProcessorTask.call(ContinuallyRunProcessorTask.java:47) [nifi-framework-core-1.1.0.2.1.1.0-2.jar:1.1.0.2.1.1.0-2]
        at org.apache.nifi.controller.scheduling.TimerDrivenSchedulingAgent$1.run(TimerDrivenSchedulingAgent.java:132) [nifi-framework-core-1.1.0.2.1.1.0-2.jar:1.1.0.2.1.1.0-2]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511) [na:1.8.0_77]
        at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:308) [na:1.8.0_77]
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:180) [na:1.8.0_77]
        at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:294) [na:1.8.0_77]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [na:1.8.0_77]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [na:1.8.0_77]
        at java.lang.Thread.run(Thread.java:745) [na:1.8.0_77]
Caused by: com.fasterxml.jackson.databind.JsonMappingException: (was java.lang.ArrayIndexOutOfBoundsException) (through reference chain: java.util.LinkedHashMap["xml"])
        at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:210) ~[jackson-databind-2.6.1.jar:2.6.1]
        at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:177) ~[jackson-databind-2.6.1.jar:2.6.1]
        at com.fasterxml.jackson.databind.deser.std.ContainerDeserializerBase.wrapAndThrow(ContainerDeserializerBase.java:88) ~[jackson-databind-2.6.1.jar:2.6.1]
        at com.fasterxml.jackson.databind.deser.std.MapDeserializer._readAndBindStringMap(MapDeserializer.java:507) ~[jackson-databind-2.6.1.jar:2.6.1]
        at com.fasterxml.jackson.databind.deser.std.MapDeserializer.deserialize(MapDeserializer.java:341) ~[jackson-databind-2.6.1.jar:2.6.1]
        at com.fasterxml.jackson.databind.deser.std.MapDeserializer.deserialize(MapDeserializer.java:26) ~[jackson-databind-2.6.1.jar:2.6.1]
        at com.fasterxml.jackson.databind.deser.std.UntypedObjectDeserializer.deserialize(UntypedObjectDeserializer.java:220) ~[jackson-databind-2.6.1.jar:2.6.1]
        at com.fasterxml.jackson.databind.ObjectMapper._readMapAndClose(ObjectMapper.java:3702) ~[jackson-databind-2.6.1.jar:2.6.1]
        at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:2784) ~[jackson-databind-2.6.1.jar:2.6.1]
        at com.bazaarvoice.jolt.JsonUtilImpl.jsonToObject(JsonUtilImpl.java:102) ~[json-utils-0.0.21.jar:0.0.21]
        ... 14 common frames omitted

I believe the stack trace suggests the processor fails to read JSON from your flowfile. Is the failing flowfile's actual content different from what you pasted above and into the Advanced UI? — James
the content has special characters in it - like e.g. "1.0 | 2.0 | 3.0" but inside "" — Daniel
Can you check if it is well-formed JSON by loading it using a different NiFi processor or external tool that parses JSON? EvaluateJsonPath might work. — James
JSON is well formatted - we have not eliminated JOLT and solved the dilemma by adapting xQuery and XSLT — Daniel

mattyb mattyb · Accepted Answer · 2017-03-24T19:31:21

I was unable to reproduce, but I am using the latest source code (which will at some point become NiFi 1.2.0) which has an upgrade of the Jolt library as well as some changes to the JoltTransformJSON processor. I pasted in the JSON above and the spec, and it converted fine.

Is the JSON being passed to JoltTransformJSON using a character set other than the Java default (often UTF-8)? If so, try a ConvertCharacterSet processor before the JoltTransformJSON processor.

NiFi JoltTransformJSON

2 Answers