[UIMA-5588] uv3: NPE during deserialization under certain circumstances

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 3.0.0SDK-beta
• Fix Version/s: 3.0.0SDK
• Component/s: Core Java Framework
• Assignee: Marshall Schor
• Reporter: Richard Eckart de Castilho
• Created: 26/Sep/17 10:30
• Updated: 30/Oct/18 19:38
• Resolved: 28/Sep/17 02:31

Description

This was previously thought to be covered by UIMA-5586 - however, the problem remains after the order of the deserialization had been fixed in UIMA-5586.

When deserializing some binary CAS formats, there is a NPE in certain cases. Here is an example that might serve for reproduction:

    @Test
    public void test6LenientPlainUima() throws Exception
    {
        CAS source = JCasFactory.createJCas().getCas();
        CAS target = JCasFactory.createJCas().getCas();

        new DocumentMetaData(source.getJCas(), 0, 0).addToIndexes();

        @SuppressWarnings("resource")
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        CasIOUtils.save(source, bos, COMPRESSED_FILTERED);
        bos.close();
        
        CasIOUtils.load(new ByteArrayInputStream(bos.toByteArray()), target);
    }

Mind this is a minimal code for reproduction. The same happens when deserializing within the context of an initialized AnalysisEngine.

The NPE only seems to be thrown when the `DocumentMetaData` is added via JCas:

java.lang.NullPointerException
	at org.apache.uima.cas.impl.CASImpl.getView(CASImpl.java:2224)
	at org.apache.uima.cas.impl.BinaryCasSerDes6.deserializeAfterVersion(BinaryCasSerDes6.java:1892)
	at org.apache.uima.cas.impl.BinaryCasSerDes.reinit(BinaryCasSerDes.java:595)
	at org.apache.uima.util.CasIOUtils.load(CasIOUtils.java:382)
	at org.apache.uima.util.CasIOUtils.load(CasIOUtils.java:313)
	at org.apache.uima.util.CasIOUtils.load(CasIOUtils.java:237)
        ...

I have set up a similar test using only the plain CAS API which seems to work fine:

    @Test
    public void test6LenientPlainUima2() throws Exception
    {
        TypeSystemDescription tsd = new TypeSystemDescription_impl();
        TypeDescription td = tsd.addType("DocumentMetaData", "", CAS.TYPE_NAME_DOCUMENT_ANNOTATION);
        td.addFeature("feat", "", CAS.TYPE_NAME_STRING);
        
        CAS source = CasCreationUtils.createCas(tsd, null, null, null);
        CAS target = CasCreationUtils.createCas(tsd, null, null, null);

        AnnotationFS dmd = source
                .createAnnotation(source.getTypeSystem().getType("DocumentMetaData"), 0, 0);
        source.addFsToIndexes(dmd);
        assertEquals("DocumentMetaData", source.getDocumentAnnotation().getType().getName());

        @SuppressWarnings("resource")
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        CasIOUtils.save(source, bos, COMPRESSED_FILTERED);
        bos.close();
        
        CasIOUtils.load(new ByteArrayInputStream(bos.toByteArray()), target);
    }