NullPointerException when Deactivating type mapping

[Joalien]

To deactivate the type mapping, the documentation advises to set typeKey to null

As explained in the documentation

deactivating type mapping may lead to exceptions when reading the entities from the DB.

In the method com.arangodb.springframework.core.convert.DefaultArangoTypeMapper.DefaultTypeAliasAccessor#readAliasFrom, the call source.get(this.typeKey); throws a NullPointerException when this.typeKey is null. I suggest to add a non-null check before

before

if (source.isObject()) {
    final VPackSlice typeKey = source.get(this.typeKey);
    return Alias.ofNullable(typeKey.isString() ? typeKey.getAsString() : null);
}

after

if (source.isObject()) {
    if (this.typeKey == null) return Alias.NONE;
    final VPackSlice typeKey = source.get(this.typeKey);
    return Alias.ofNullable(typeKey.isString() ? typeKey.getAsString() : null);
}

Here is the linked pull request

[rashtao]

VPackSlice.get(String) does not require a non-null argument. In such case it should return a VPackSlice.NONE_SLICE.
Can you please provide the stacktrace of the exception? Or can you include a test in your PR?

[Joalien]

Here is my stacktrace :

java.lang.NullPointerException
	at java.lang.String.compareTo(String.java:1155)
	at com.arangodb.velocypack.VPackSlice.compareString(VPackSlice.java:757)
	at com.arangodb.velocypack.VPackSlice.searchObjectKeyBinary(VPackSlice.java:585)
	at com.arangodb.velocypack.VPackSlice.get(VPackSlice.java:524)
	at com.arangodb.springframework.core.convert.DefaultArangoTypeMapper$DefaultTypeAliasAccessor.readAliasFrom(DefaultArangoTypeMapper.java:183)
	at com.arangodb.springframework.core.convert.DefaultArangoTypeMapper.readType(DefaultArangoTypeMapper.java:97)
	at com.arangodb.springframework.core.convert.DefaultArangoTypeMapper.readType(DefaultArangoTypeMapper.java:105)
	at com.arangodb.springframework.core.convert.DefaultArangoConverter.readInternal(DefaultArangoConverter.java:141)
	at com.arangodb.springframework.core.convert.DefaultArangoConverter.read(DefaultArangoConverter.java:129)
	at com.arangodb.springframework.core.convert.DefaultArangoConverter.read(DefaultArangoConverter.java:88)
	at com.arangodb.springframework.core.template.ArangoExtCursorIterator.deserialize(ArangoExtCursorIterator.java:60)
	at com.arangodb.internal.cursor.ArangoCursorIterator.next(ArangoCursorIterator.java:75)
	at com.arangodb.internal.cursor.ArangoCursorImpl.next(ArangoCursorImpl.java:112)
	at com.arangodb.springframework.repository.query.ArangoResultConverter.getNext(ArangoResultConverter.java:251)
	at com.arangodb.springframework.repository.query.ArangoResultConverter.convertResult(ArangoResultConverter.java:120)
	at com.arangodb.springframework.repository.query.AbstractArangoQuery.convertResult(AbstractArangoQuery.java:189)
	at com.arangodb.springframework.repository.query.AbstractArangoQuery.execute(AbstractArangoQuery.java:82)
	at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:605)
	at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.lambda$invoke$3(RepositoryFactorySupport.java:595)
	at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:595)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:59)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:93)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:61)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)
	at com.sun.proxy.$Proxy97.findUserByUsername(Unknown Source)
        ...

[rashtao]

The stacktrace does not seem to be related to com.arangodb:velocypack:2.4.1. Can you please check which version of com.arangodb:velocypack you are using?

[Joalien]

Indeed, I was using com.arangodb:velocypack:1.4.1.
I updated velocypack version and here is the stackstrace :

java.lang.NullPointerException
	at com.arangodb.velocypack.VPackSlice.searchObjectKeyBinary(VPackSlice.java:698)
	at com.arangodb.velocypack.VPackSlice.get(VPackSlice.java:649)
	at com.arangodb.springframework.core.convert.DefaultArangoTypeMapper$DefaultTypeAliasAccessor.readAliasFrom(DefaultArangoTypeMapper.java:183)
	at com.arangodb.springframework.core.convert.DefaultArangoTypeMapper.readType(DefaultArangoTypeMapper.java:97)
	at com.arangodb.springframework.core.convert.DefaultArangoTypeMapper.readType(DefaultArangoTypeMapper.java:105)
	at com.arangodb.springframework.core.convert.DefaultArangoConverter.readInternal(DefaultArangoConverter.java:126)
	at com.arangodb.springframework.core.convert.DefaultArangoConverter.read(DefaultArangoConverter.java:114)
	at com.arangodb.springframework.core.convert.DefaultArangoConverter.read(DefaultArangoConverter.java:73)
	at com.arangodb.springframework.core.template.ArangoExtCursorIterator.deserialize(ArangoExtCursorIterator.java:60)
	at com.arangodb.internal.cursor.ArangoCursorIterator.next(ArangoCursorIterator.java:74)
	at com.arangodb.internal.cursor.ArangoCursorImpl.next(ArangoCursorImpl.java:111)
	at com.arangodb.springframework.repository.query.ArangoResultConverter.getNext(ArangoResultConverter.java:251)
	at com.arangodb.springframework.repository.query.ArangoResultConverter.convertResult(ArangoResultConverter.java:120)
	at com.arangodb.springframework.repository.query.AbstractArangoQuery.convertResult(AbstractArangoQuery.java:189)
	at com.arangodb.springframework.repository.query.AbstractArangoQuery.execute(AbstractArangoQuery.java:82)
	at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.doInvoke(RepositoryFactorySupport.java:605)
	at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.lambda$invoke$3(RepositoryFactorySupport.java:595)
	at org.springframework.data.repository.core.support.RepositoryFactorySupport$QueryExecutorMethodInterceptor.invoke(RepositoryFactorySupport.java:595)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at org.springframework.data.projection.DefaultMethodInvokingMethodInterceptor.invoke(DefaultMethodInvokingMethodInterceptor.java:59)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:93)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at org.springframework.data.repository.core.support.SurroundingTransactionDetectorMethodInterceptor.invoke(SurroundingTransactionDetectorMethodInterceptor.java:61)
	at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:186)
	at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:212)
	at com.sun.proxy.$Proxy97.findUserByUsername(Unknown Source)

[rashtao]

Thanks for reporting, I see the problem now!
VPackSlice.get(null) returns from some if-else branches VPackSlice.NONE_SLICE and from others throws NPE.
I fixed here, a patch release will follow soon.

[rashtao]

fix released: https://github.com/arangodb/spring-data/releases/tag/v3.4.0