Remove Paranamer usage where possible

[zhao-zihao]

I have a project based on scala 2.13, JDK 8, and jackson-module-scala 2.11.0. Recently we upgrade to JDK 11.

Then jackson-module-scala throw an IndexOutOfBoundsException from BytecodeReadingParanamer class.
I noticed that the BeanIntrospector.scala of the jackson-module-scala import the problematic com.thoughtworks.paranamer.BytecodeReadingParanamer, which hasn't get updated since 4 years ago and it only support JDK 8.

[pjfanning]

jackson-module-scala unit tests run ok on OpenJDK 11 - see https://travis-ci.org/github/FasterXML/jackson-module-scala/builds/693266062 - if you provide a reproducible test case, we can look at it

[zhao-zihao]

@pjfanning Thanks for your help! I solved the issue!

We have a class like this:

@JsonInclude(JsonInclude.Include.NON_NULL)
public class ExampleProperty {
    @JsonProperty("name") private String name = null;
    @JsonProperty("value") private String value = null;

    @JsonCreator
    public ExampleProperty(String name, String value) {
        this.name = name;
        this.value = value;
        validate();
    }

The above code worked in JDK 8 but failed in JDK 11.

To make it work, I removed the ScalaAnnotationIntrospectorModule of DefaultScalaModule, which uses the paranamer library(supports JDK 8) to get parameter names using Java reflection. To solve this, I added @JsonProperty annotation to arguments. And the code would be like this:

@JsonInclude(JsonInclude.Include.NON_NULL)
public class ExampleProperty {
    @JsonProperty("name") private String name = null;
    @JsonProperty("value") private String value = null;

    @JsonCreator
    public ExampleProperty(@JsonProperty("name") String name, @JsonProperty("value") String value) {
        this.name = name;
        this.value = value;
        validate();
    }

[pjfanning]

@zhao-zihao that code you provided is plain java and not scala - do you use scala at all and if not, can you just remove the jackson-module-scala dependency?

[pjfanning]

@cowtowncoder it's easy to drop paranamer usage in jackson-module-scala if we replace it with Java8 specific code. With Jackson 3, is it the intention to drop support for Java 7 and below?

https://stackoverflow.com/questions/21455403/how-to-get-method-parameter-names-in-java-8-using-reflection

[cowtowncoder]

@pjfanning Yes, Jackson 3.0 is Java8+ only at this point and earlier versions will not be supported. There may even be question of requiring some later JDK version, but JDK8 for sure.

In addition, every module can decided if they might want to go Java 8 with 2.x as well: some modules do that (jackson-module-kotlin requires Java 8, and I think some datatype modules might as well). So it might make sense to consider going Java 8 with Scala module 2.12, for example?

[pjfanning]

Thanks @cowtowncoder, I would favour dropping Java 7 support in jackson-module-scala 2.12.0.

I might even try to remove the dependency on jackson-module-paranamer in jackson-module-scala 2.12.0.

[zhao-zihao]

@zhao-zihao that code you provided is plain java and not scala - do you use scala at all and if not, can you just remove the jackson-module-scala dependency?

@pjfanning
Yes. I am using the scala Play Framework 2.8.2.
The app will give me an error like the following if I remove the jackson-module-scala completely.

[info]   com.**.exception.ExampleException: Invalid data for JSON processing. com.fasterxml.jackson.databind.exc.MismatchedInputException: Cannot deserialize instance of `java.util.HashSet<com.**.ShowExpressionAsType>` out of START_OBJECT token

Then I add back the IterableModule to deserialize a HashSet parameter in HTTP Request.
ExampleIterableModule.scala:

import com.fasterxml.jackson.module.scala.{ IterableModule}
class ExampleIterableModule extends IterableModule {}

JsonAPISerizlizer.java:

new ObjectMapper().registerModule(new ExampleIterableModule())

[pjfanning]

So, in jackson-module-scala 2.12.0-SNAPSHOT, I have dropped java 7 support (which only affects scala 2.10/2.11 as scala 2.12/2.13 already only supported java 8). I have removed the dependency on jackson-module-paranamer.

scala 2.10/2.11 builds still need paranamer as these scala versions build java classes without full java8 support.

[cowtowncoder]

Note: Scala 2.10 support was dropped from Jackson 2.12 so Paranamer dependency only exists for Scala 2.11.

[afsilvasantos]

I am having the original problem right now. My situation is a bit different though. The error started appearing in the Unit Tests after upgrading Play Framework from version 2.7.9 to 2.8.17.
As of before the upgrade, I am using Scala 2.13.8 version.

This is the unit test method that fails:

    @Before
    public void setup() {
        AfvPartyLinkRequest dto = random(AfvPartyLinkRequest.class);
        request = fakeRequest().bodyJson(Json.toJson(dto)).build();

        when(userMock.hasRole(ACCOUNT_MANAGER)).thenReturn(true);
    }

Anywhere there is a call of Json.toJson(Object), it throws the index out of bounds exception like this:

[error] Test services.linking.FundPartyLinkerTest.testSuccessfullyLinkEntities failed: java.lang.RuntimeException: java.lang.ArrayIndexOutOfBoundsException: Index 29743 out of bounds for length 140, took 0.161 sec
[error]     at play.libs.Json.toJson(Json.java:94)
[error]     at services.linking.FundPartyLinkerTest.testSuccessfullyLinkEntities(FundPartyLinkerTest.java:91)
[error]     at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
[error]     at jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
[error]     at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[error]     at java.lang.reflect.Method.invoke(Method.java:566)
[error]     ...
[error] Caused by: java.lang.ArrayIndexOutOfBoundsException: Index 29743 out of bounds for length 140
[error]     at com.fasterxml.jackson.module.paranamer.shaded.BytecodeReadingParanamer$ClassReader.accept(BytecodeReadingParanamer.java:577)
[error]     at com.fasterxml.jackson.module.paranamer.shaded.BytecodeReadingParanamer$ClassReader.access$200(BytecodeReadingParanamer.java:338)
[error]     at com.fasterxml.jackson.module.paranamer.shaded.BytecodeReadingParanamer.lookupParameterNames(BytecodeReadingParanamer.java:103)
[error]     at com.fasterxml.jackson.module.paranamer.shaded.CachingParanamer.lookupParameterNames(CachingParanamer.java:90)
[error]     at com.fasterxml.jackson.module.paranamer.SerializableParanamer.findParameterName(SerializableParanamer.java:50)
[error]     at com.fasterxml.jackson.module.paranamer.ParanamerAnnotationIntrospector.findImplicitPropertyName(ParanamerAnnotationIntrospector.java:67)
[error]     at com.fasterxml.jackson.databind.introspect.AnnotationIntrospectorPair.findImplicitPropertyName(AnnotationIntrospectorPair.java:490)
[error]     at com.fasterxml.jackson.databind.introspect.AnnotationIntrospectorPair.findImplicitPropertyName(AnnotationIntrospectorPair.java:489)
[error]     at com.fasterxml.jackson.databind.introspect.POJOPropertiesCollector._addCreatorParam(POJOPropertiesCollector.java:512)
[error]     at com.fasterxml.jackson.databind.introspect.POJOPropertiesCollector._addCreators(POJOPropertiesCollector.java:500)
[error]     at com.fasterxml.jackson.databind.introspect.POJOPropertiesCollector.collectAll(POJOPropertiesCollector.java:327)
[error]     at com.fasterxml.jackson.databind.introspect.POJOPropertiesCollector.getJsonValueAccessor(POJOPropertiesCollector.java:203)
[error]     at com.fasterxml.jackson.databind.introspect.BasicBeanDescription.findJsonValueAccessor(BasicBeanDescription.java:252)
[error]     at com.fasterxml.jackson.databind.ser.BasicSerializerFactory.findSerializerByAnnotations(BasicSerializerFactory.java:396)
[error]     at com.fasterxml.jackson.databind.ser.BeanSerializerFactory._createSerializer2(BeanSerializerFactory.java:216)
[error]     at com.fasterxml.jackson.databind.ser.BeanSerializerFactory.createSerializer(BeanSerializerFactory.java:165)
[error]     at com.fasterxml.jackson.databind.SerializerProvider._createUntypedSerializer(SerializerProvider.java:1474)
[error]     at com.fasterxml.jackson.databind.SerializerProvider._createAndCacheUntypedSerializer(SerializerProvider.java:1422)
[error]     at com.fasterxml.jackson.databind.SerializerProvider.findValueSerializer(SerializerProvider.java:521)
[error]     at com.fasterxml.jackson.databind.SerializerProvider.findTypedValueSerializer(SerializerProvider.java:799)
[error]     at com.fasterxml.jackson.databind.ser.DefaultSerializerProvider.serializeValue(DefaultSerializerProvider.java:308)
[error]     at com.fasterxml.jackson.databind.ObjectMapper.writeValue(ObjectMapper.java:3058)
[error]     at com.fasterxml.jackson.databind.ObjectMapper.valueToTree(ObjectMapper.java:3227)
[error]     at play.libs.Json.toJson(Json.java:92)

How can I overcome this? I checked and all jackson dependencies are on 2.11.4 version, which is the direct jackson dependency version for Play 2.8.17

[pjfanning]

@afsilvasantos where is jackson-module-scala in your stacktrace? You seem to be using play-json and play-json does not use jackson-module-scala - it only used plain jackson-databind.

Please do not raise this as a jackson-databind issue either - the Jackson team have limited time and will not want to debug Play for you. A Jackson only test case is what is needed if you expect anyone from Jackson team to debug your issue for you.