`Binary` not deserialized to `byte[]` for property of type `Object`

[gtomassi]

When upgrading to the latest driver release (3.1.7 -> 3.2.1), our unit tests break due to improper deserialization of type org.bson.types.Binary. For some reason it is no longer being deserialized to a byte[] and left as the Binary class.

[christophstrobl]

Do you have the test handy? A complete minimal sample (something that we can unzip or git clone, build, and deploy) that reproduces the problem helps us a lot identify the issue.

[gtomassi]

@christophstrobl Here you go..

• Output w/ 3.2.1 -> OUT: TestDomainObject{foo='bar', value=org.bson.types.Binary@403} -> SAME: false
• Output w/ 3.1.7 -> OUT: TestDomainObject{foo='bar', value=[B@14f6b800} -> SAME: true

    public static class TestDomainObject<V> {

        protected String foo;
        protected V value;

        @Override
        public String toString() {
            return "TestDomainObject{" +
                    "foo='" + foo + '\'' +
                    ", value=" + value +
                    '}';
        }
    }

    @Test
    public void testBrokenExample() {

        ReactiveMongoOperations mongo = injector.getInstance(ReactiveMongoOperations.class);

        Query query = new Query(where("foo").is("bar"));
        mongo.upsert(query, new Update().set("value", new byte[] {0x00, 0x42}), "exampleCollection").block();
        TestDomainObject<?> out = mongo.findOne(query, TestDomainObject.class, "exampleCollection").block();

        System.out.println("OUT: " + out + "  -> SAME: " + deepEquals(new byte[] {0x00, 0x42}, out.value));

    }

[christophstrobl]

Thanks for the feedback.
I gave the test a try with current spring-data maintenance branches, and I did not see a change in behavior between the versions in that regard.
Since binary data is considered a MongoDB native type (which means on write no type hint is added for it) no conversion will happen if the domain type does not infer a certain target type.
In the test above Object is used for the value property. So, whatever the MongoDB driver returns for the field will be used.
Things look different for a typed domain object (like below). In that case we can identify the target type and convert the result accordingly.

public static class TypedDomainObject extends TestDomainObject<byte[]> {}
// ...
TestDomainObject<?> out = template.findOne(query, TypedDomainObject.class, "exampleCollection");

Maybe I'm missing something here, in that case please provide a sample GH project with all required dependencies, and we'll be happy to have another look.

[spring-projects-issues]

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[spring-projects-issues]

Closing due to lack of requested feedback. If you would like us to look at this issue, please provide the requested information and we will re-open the issue.

[gtomassi]

@otasman Could use your help putting together a mini gradle/intellij project or something that replicates the issue so they can replicate it.