Getting output in json

[Syed Moinuddin]

HI,

I want to get the output in json, I'm trying the following program,

public static void main(final String... args) throws IOException,
UIMAException, SAXException {
        final String note = "Serum Cholesterol 154 150 250
mgs/dl\n-\nSerum Triglycerides 67 90 200 mgs /dl\n-\nSerum HDL:
Cholesterol 38 35 55 mgs /dl\n-\nSerum LDL: Cholesterol 49 85 150
mgs/d1\n-\nSerum VLDL: Cholesterol 13 10 40 mgs/dl\n-\nTotal
Cholesterol / HDL Ratio: 3.90\";
        final JCas jcas = JCasFactory.createJCas();
        jcas.setDocumentText(note);
//        final AnalysisEngineDescription aed = getDefaultPipeline();
        final AnalysisEngineDescription aed = getFastPipeline();  //
Outputs from default and fast pipeline are identical
        SimplePipeline.runPipeline(jcas, aed);

        Collection<TOP> codes = JCasUtil.selectAll(jcas);
        List<TOP> list = new ArrayList<>(codes)

        TOP [] res = list.toArray(new TOP[list.size()]);

//        System.out.println(Arrays.toString(res));

        String json = new Gson().toJson(res);
        System.out.println(json);

    }

But this gives following error,

Exception in thread "main" java.lang.IllegalArgumentException: class
org.apache.uima.jcas.tcas.DocumentAnnotation_Type declares multiple
JSON fields named fsGenerator
        at 
com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.getBoundFields(ReflectiveTypeAdapterFactory.java:122)
        at 
com.google.gson.internal.bind.ReflectiveTypeAdapterFactory.create(ReflectiveTypeAdapterFactory.java:72)
        at com.google.gson.Gson.getAdapter(Gson.java:353)
        at 
com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:55)
        at 
com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.write(ReflectiveTypeAdapterFactory.java:89)
        at 
com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.write(ReflectiveTypeAdapterFactory.java:195)
        at 
com.google.gson.internal.bind.TypeAdapterRuntimeTypeWrapper.write(TypeAdapterRuntimeTypeWrapper.java:68)
        at 
com.google.gson.internal.bind.ArrayTypeAdapter.write(ArrayTypeAdapter.java:93)
        at com.google.gson.Gson.toJson(Gson.java:586)
        at com.google.gson.Gson.toJson(Gson.java:565)
        at com.google.gson.Gson.toJson(Gson.java:520)
        at com.google.gson.Gson.toJson(Gson.java:500)
        at 
org.apache.ctakes.clinicalpipeline.ExtractNEs.main(ExtractNEs.java:146)

Any guidance would be really helpful.

Thanks