serialize/map NULL values from db to fields

[Pokerkoffer]

Hi there,

JSON in MongoDB 3.x:

{
    "_id" : "somehex",
    "name" : "a Name",
   "someobject": null
}

Class to map to:

@Entity
public class MyClass {
    @Id
    @JsonProperty
    private String id;

    @NotEmpty
    @JsonProperty
    private String name;

    @JsonProperty
    private SomeObject someobject;
}

My code, that retrieves the values from mongodb:

        FindIterable<MyClass> myClasses = myClassCollection.find(query.toBson(true));
        return myClasses.into(new ArrayList<MyClass>());

When i try to map this back to a class it gives me an error:

readStartDocument can only be called when CurrentBSONType is DOCUMENT, not when CurrentBSONType is NULL.

Stacktrace:

ERROR [2017-01-07 15:03:58,066] com.washingtonpost.dropwizard.exceptions.mappers.RuntimeExceptionMapper: readStartDocument can only be called when CurrentBSONType is DOCUMENT, not when CurrentBSONType is NULL.
! org.bson.BsonInvalidOperationException: readStartDocument can only be called when CurrentBSONType is DOCUMENT, not when CurrentBSONType is NULL.
! at org.bson.AbstractBsonReader.verifyBSONType(AbstractBsonReader.java:692)
! at org.bson.AbstractBsonReader.checkPreconditions(AbstractBsonReader.java:724)
! at org.bson.AbstractBsonReader.readStartDocument(AbstractBsonReader.java:452)
! at eu.dozd.mongo.EntityCodec.decode(EntityCodec.java:63)
! at eu.dozd.mongo.EntityCodec.decode(EntityCodec.java:69)
! at com.mongodb.operation.CommandResultArrayCodec.decode(CommandResultArrayCodec.java:52)
! at com.mongodb.operation.CommandResultDocumentCodec.readValue(CommandResultDocumentCodec.java:53)
! at org.bson.codecs.BsonDocumentCodec.decode(BsonDocumentCodec.java:84)
! at org.bson.codecs.BsonDocumentCodec.decode(BsonDocumentCodec.java:41)
! at org.bson.codecs.configuration.LazyCodec.decode(LazyCodec.java:47)
! at org.bson.codecs.BsonDocumentCodec.readValue(BsonDocumentCodec.java:101)
! at com.mongodb.operation.CommandResultDocumentCodec.readValue(CommandResultDocumentCodec.java:56)
! at org.bson.codecs.BsonDocumentCodec.decode(BsonDocumentCodec.java:84)
! at org.bson.codecs.BsonDocumentCodec.decode(BsonDocumentCodec.java:41)
! at com.mongodb.connection.ReplyMessage.<init>(ReplyMessage.java:57)
! at com.mongodb.connection.CommandProtocol.getResponseDocument(CommandProtocol.java:139)
! at com.mongodb.connection.CommandProtocol.execute(CommandProtocol.java:118)
! at com.mongodb.connection.DefaultServer$DefaultServerProtocolExecutor.execute(DefaultServer.java:168)
! at com.mongodb.connection.DefaultServerConnection.executeProtocol(DefaultServerConnection.java:289)
! at com.mongodb.connection.DefaultServerConnection.command(DefaultServerConnection.java:176)
! at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:216)
! at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:207)
! at com.mongodb.operation.CommandOperationHelper.executeWrappedCommandProtocol(CommandOperationHelper.java:113)
! at com.mongodb.operation.FindOperation$1.call(FindOperation.java:516)
! at com.mongodb.operation.FindOperation$1.call(FindOperation.java:510)
! at com.mongodb.operation.OperationHelper.withConnectionSource(OperationHelper.java:431)
! at com.mongodb.operation.OperationHelper.withConnection(OperationHelper.java:404)
! at com.mongodb.operation.FindOperation.execute(FindOperation.java:510)
! at com.mongodb.operation.FindOperation.execute(FindOperation.java:81)
! at com.mongodb.Mongo.execute(Mongo.java:836)
! at com.mongodb.Mongo$2.execute(Mongo.java:823)
! at com.mongodb.OperationIterable.iterator(OperationIterable.java:47)
! at com.mongodb.OperationIterable.forEach(OperationIterable.java:70)
! at com.mongodb.OperationIterable.into(OperationIterable.java:82)
! at com.mongodb.FindIterableImpl.into(FindIterableImpl.java:171)
.
.
.

How can i fix this? Is this an error when mapping back to POJOs?

Thanks!

[dozd]

I'll have a look at it.

[dozd]

Will be released shortly as 1.0.7.

[Pokerkoffer]

Awesome, Thank you very much!