Adding a deep mapping causes a null pointer exception, ModelMapper 1.1.0

[richa...@gmail.com]

I'm trying to configure a ModelMapper (version 1.1.0) to do a deep mapping between source and destination with the following code:

@Bean

public ModelMapper modelMapper() {

ModelMapper modelMapper = new ModelMapper();

try {

modelMapper.getConfiguration().setAmbiguityIgnored(true);

Converter<Optional<LocalDate>, LocalDate> toLocalDate =

    ctx -> ctx.getSource() == null ? null : ctx.getSource().orElse(null);

    

modelMapper.addConverter(toLocalDate);

Converter<Optional<StandardId>, String> toIdString = 

ctx -> ctx.getSource() == null ? null : ctx.getSource().map(StandardId::getValue).orElse(null);

modelMapper.addConverter(toIdString);

TypeMap<FxVanillaOption, FxVanillaOptionDto> typeMap = modelMapper.createTypeMap(FxVanillaOption.class, FxVanillaOptionDto.class);

typeMap.addMapping(src -> src.getExpiryZone().getId(), FxVanillaOptionDto::setExpiryZone);

} catch (Exception e) {

e.printStackTrace();

}

    return modelMapper;

}

I'm getting a NPE here in ReferenceMapExpressionImpl where source = null

  public <V> void map(SourceGetter<S> sourceGetter, DestinationSetter<D, V> destinationSetter) {

    PropertyReferenceCollector collector = new PropertyReferenceCollector(typeMap.configuration, options);

    S source = ProxyFactory.proxyFor(typeMap.getSourceType(), collector.newSourceInterceptor(), collector.getErrors());

    sourceGetter.get(source);

    D destination = ProxyFactory.proxyFor(typeMap.getDestinationType(), collector.newDestinationInterceptor(), collector.getErrors());

    destinationSetter.accept(destination, destinationValue(destinationSetter));

    typeMap.addMapping(collector.collect());

  }

My source class doesn't have a default construct (it's an immutable Joda Bean). Is this the cause?

java.lang.NullPointerException

at com.derivativepath.analytics.AnalyticsFxServiceApplication.lambda$3(AnalyticsFxServiceApplication.java:54)

at org.modelmapper.internal.ReferenceMapExpressionImpl.map(ReferenceMapExpressionImpl.java:52)

at org.modelmapper.internal.TypeMapImpl.addMapping(TypeMapImpl.java:231)

at com.derivativepath.analytics.AnalyticsFxServiceApplication.modelMapper(AnalyticsFxServiceApplication.java:54)

[richa...@gmail.com]

I think this might be due to my source and destination classes being marked as "final". Which leads me to another question: The destination class is not owned by me (it's a 3rd party binary) how can I get around this issue?

[Chun Han Hsiao]

Hi,

You are right about the finding, our explicit mapping configuration is based on proxying the source/destination class and we cannot proxy a final class so it turns out a NullPointerException.

ModelMapper seems to not have any friendly api to support explicit mapping on a final class.

Currently, I don't have any idea or workaround to solve this problem.. I will think about how ModelMapper support final class explicit mapping..

Regards,

Chun Han

richa...@gmail.com於 2017年10月11日星期三 UTC+8下午11時50分45秒寫道：

[Jonathan Halterman]

Proxying final classes is going to be problematic - it just isn't supported by Cglib (and I'm guessing not by ByteBuddy as well without an agent). That said, we should be able to make a better guess about when proxying fails and report an appropriate error rather than NullPointerException. Without looking at the code - I recall that previously we were detecting NullPointers within a proxy interceptor and reporting an error message that mentioned a possible final method.

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[Chun Han Hsiao]

I think it might cause by https://github.com/modelmapper/modelmapper/pull/266 that I try resolve https://github.com/modelmapper/modelmapper/issues/260. I will try fix the NullPointerException problem, and consider to use ByteBuddy instead of CGLIB.

Jonathan Halterman於 2017年10月12日星期四 UTC+8下午2時44分32秒寫道：

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