Graphhopper: Get rid of warning when running web service with JDK11

[karussell]

Currently we get:

WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by com.fasterxml.jackson.module.afterburner.util.MyClassLoader (file:/home/peter/.m2/repository/com/fasterxml/jackson/module/jackson-module-afterburner/2.9.5/jackson-module-afterburner-2.9.5.jar) to method java.lang.ClassLoader.defineClass(java.lang.String,byte[],int,int)
WARNING: Please consider reporting this to the maintainers of com.fasterxml.jackson.module.afterburner.util.MyClassLoader
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release

for JDK10 due to https://github.com/FasterXML/jackson-modules-base/issues/37

The suggested workaround does not work at the moment.

For the commits see https://github.com/graphhopper/graphhopper/commits/tryjdk10_2

[karussell]

This seems to work:

bootstrap.setObjectMapper(Jackson.newMinimalObjectMapper()); // without Afterburner module

but then we get:

WARNING: An illegal reflective access operation has occurred
WARNING: Illegal reflective access by com.fasterxml.jackson.databind.util.ClassUtil (file:/2.9.6/jackson-databind-2.9.6.jar) to constructor java.util.Optional()
WARNING: Please consider reporting this to the maintainers of com.fasterxml.jackson.databind.util.ClassUtil
WARNING: Use --illegal-access=warn to enable warnings of further illegal reflective access operations
WARNING: All illegal access operations will be denied in a future release

[karussell]

It was suggested from @cowtowncoder here to include

<dependency>
    <groupId>com.fasterxml.jackson.datatype</groupId>
    <artifactId>jackson-datatype-jdk8</artifactId>
    <version>${jackson.version}</version>
</dependency>

Have set the special ObjectMapper here and included this snippet here using JDK10 and the latest JDK11 build, but I still get the warning about ClassUtil. Is there something else necessary?

[cowtowncoder]

For what it is worth, I would be interested in figuring out where the call comes from, if it was possible to provide a stand-alone, ideally 0-dep reproduction. Basic jackson-databind does not refer to Optional (since JDK baseline for 2.x is still JDK 7) normally, but I could see how it would happen if there is no explicit deserializer.
But if addition of module did not prevent it there is probably some other codepath and it would be great to know where the calls comes from -- simple stack trace should be enough.

[karussell]

Thanks a lot for taking your time for this issue!

I found out how to create the stack trace :) (adding "--illegal-access=deny to the VM arguments) and now this gives me:

io.dropwizard.configuration.ConfigurationParsingException: config.yml has an error:
  * Failed to parse configuration at: server.applicationConnectors.[0]; Unable to make private java.util.Optional() accessible: module java.base does not "opens java.util" to unnamed module @22d6f11 (through reference chain: com.graphhopper.http.GraphHopperServerConfiguration["server"]->io.dropwizard.server.DefaultServerFactory["applicationConnectors"]->java.util.ArrayList[0])

    at io.dropwizard.configuration.ConfigurationParsingException$Builder.build(ConfigurationParsingException.java:279)
    at io.dropwizard.configuration.BaseConfigurationFactory.build(BaseConfigurationFactory.java:156)
    at io.dropwizard.configuration.BaseConfigurationFactory.build(BaseConfigurationFactory.java:89)
    at io.dropwizard.cli.ConfiguredCommand.parseConfiguration(ConfiguredCommand.java:126)
    at io.dropwizard.cli.ConfiguredCommand.run(ConfiguredCommand.java:74)
    at io.dropwizard.cli.Cli.run(Cli.java:78)
    at io.dropwizard.Application.run(Application.java:93)
    at com.graphhopper.http.GraphHopperApplication.main(GraphHopperApplication.java:34)
Caused by: com.fasterxml.jackson.databind.JsonMappingException: Unable to make private java.util.Optional() accessible: module java.base does not "opens java.util" to unnamed module @22d6f11 (through reference chain: com.graphhopper.http.GraphHopperServerConfiguration["server"]->io.dropwizard.server.DefaultServerFactory["applicationConnectors"]->java.util.ArrayList[0])
    at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:391)
    at com.fasterxml.jackson.databind.JsonMappingException.wrapWithPath(JsonMappingException.java:363)
    at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:302)
    at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:245)
    at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:27)
    at com.fasterxml.jackson.databind.deser.impl.MethodProperty.deserializeAndSet(MethodProperty.java:127)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:288)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer._deserializeOther(BeanDeserializer.java:189)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:161)
    at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer._deserializeTypedUsingDefaultImpl(AsPropertyTypeDeserializer.java:178)
    at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer.deserializeTypedFromObject(AsPropertyTypeDeserializer.java:105)
    at com.fasterxml.jackson.databind.deser.AbstractDeserializer.deserializeWithType(AbstractDeserializer.java:254)
    at com.fasterxml.jackson.databind.deser.impl.MethodProperty.deserializeAndSet(MethodProperty.java:136)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:288)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:151)
    at com.fasterxml.jackson.databind.ObjectMapper._readValue(ObjectMapper.java:3984)
    at com.fasterxml.jackson.databind.ObjectMapper.readValue(ObjectMapper.java:2276)
    at io.dropwizard.configuration.BaseConfigurationFactory.build(BaseConfigurationFactory.java:127)
    ... 6 more
Caused by: java.lang.reflect.InaccessibleObjectException: Unable to make private java.util.Optional() accessible: module java.base does not "opens java.util" to unnamed module @22d6f11
    at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:337)
    at java.base/java.lang.reflect.AccessibleObject.checkCanSetAccessible(AccessibleObject.java:281)
    at java.base/java.lang.reflect.Constructor.checkCanSetAccessible(Constructor.java:192)
    at java.base/java.lang.reflect.Constructor.setAccessible(Constructor.java:185)
    at com.fasterxml.jackson.databind.util.ClassUtil.checkAndFixAccess(ClassUtil.java:891)
    at com.fasterxml.jackson.databind.deser.impl.CreatorCollector._fixAccess(CreatorCollector.java:271)
    at com.fasterxml.jackson.databind.deser.impl.CreatorCollector.setDefaultCreator(CreatorCollector.java:131)
    at com.fasterxml.jackson.databind.deser.BasicDeserializerFactory._addDeserializerConstructors(BasicDeserializerFactory.java:440)
    at com.fasterxml.jackson.databind.deser.BasicDeserializerFactory._constructDefaultValueInstantiator(BasicDeserializerFactory.java:340)
    at com.fasterxml.jackson.databind.deser.BasicDeserializerFactory.findValueInstantiator(BasicDeserializerFactory.java:257)
    at com.fasterxml.jackson.databind.deser.BeanDeserializerFactory.buildBeanDeserializer(BeanDeserializerFactory.java:214)
    at com.fasterxml.jackson.databind.deser.BeanDeserializerFactory.createBeanDeserializer(BeanDeserializerFactory.java:137)
    at com.fasterxml.jackson.databind.deser.DeserializerCache._createDeserializer2(DeserializerCache.java:411)
    at com.fasterxml.jackson.databind.deser.DeserializerCache._createDeserializer(DeserializerCache.java:349)
    at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCache2(DeserializerCache.java:264)
    at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCacheValueDeserializer(DeserializerCache.java:244)
    at com.fasterxml.jackson.databind.deser.DeserializerCache.findValueDeserializer(DeserializerCache.java:142)
    at com.fasterxml.jackson.databind.DeserializationContext.findNonContextualValueDeserializer(DeserializationContext.java:467)
    at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.resolve(BeanDeserializerBase.java:473)
    at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCache2(DeserializerCache.java:293)
    at com.fasterxml.jackson.databind.deser.DeserializerCache._createAndCacheValueDeserializer(DeserializerCache.java:244)
    at com.fasterxml.jackson.databind.deser.DeserializerCache.findValueDeserializer(DeserializerCache.java:142)
    at com.fasterxml.jackson.databind.DeserializationContext.findContextualValueDeserializer(DeserializationContext.java:444)
    at com.fasterxml.jackson.databind.jsontype.impl.TypeDeserializerBase._findDeserializer(TypeDeserializerBase.java:194)
    at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer._deserializeTypedForId(AsPropertyTypeDeserializer.java:113)
    at com.fasterxml.jackson.databind.jsontype.impl.AsPropertyTypeDeserializer.deserializeTypedFromObject(AsPropertyTypeDeserializer.java:97)
    at com.fasterxml.jackson.databind.deser.AbstractDeserializer.deserializeWithType(AbstractDeserializer.java:254)
    at com.fasterxml.jackson.databind.deser.std.CollectionDeserializer.deserialize(CollectionDeserializer.java:288)
    ... 21 more

So it seems to be dropwizard (we are using version 1.3.5) and there the HttpConnectorFactory listed in the DefaultServerFactory.applicationConnectors

[stevenschlansker]

Are you positive the jackson-datatype-jdk8 module is installed? That backtrace sure looks like Jackson is trying to construct an Optional as a bean-like type, which it decidedly is not. I found similar errors in my application were all solved by making sure all object mappers had it installed (especially any "hidden" ones used by jaxrs or other machinery!)

[karussell]

Thanks @stevenschlansker - this helped and I think the following snippet will avoid warnings:

bootstrap.setObjectMapper(Jackson.newMinimalObjectMapper().registerModule(new Jdk8Module()));