arangodb / java-velocypack Goto Github PK

When serializing an object having negative int value for one of its instance field, the returned serialized object have a weird value instead of the negative int value.

For example, if I call the following piece of code with an object having -50 as value for one of its int field, the serialized value for this field is 4294967246;

VPack vpack = vpack();
System.out.println(vpack.serialize(object).toString());

Hi,

the com.arangodb.velocypack.internal.util.DateUtil does incorrect conversion of java.util.Date objects. The error is that the format is set to ISO 8601 in UTC but the time zone is not taken into account.
A date, e.g. Mon Apr 16 17:17:21 CEST 2018 would be converted to 2018-04-16T17:17:21Z, but correct would be 2018-04-16T15:17:21Z.

Fix:

SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'"); 
formatter.setTimeZone(TimeZone.getTimeZone("UTC"));

Best regards

The VPackDeserializationContext currently takes a Class<T> as a parameter. The underlying code does not require a Class<T>, it only requires the more general Type.

By accepting a Type in the VPackDeserializationContext.deserialize interface method rather than Class<T>, the user is free to pass in other implementations of Type, such as ParameterizedType which can be used to deserialize Lists with a parameterized type, as well as Maps). These parameters can be generated and "reified" by using a "type token" implementation, such as is provided in Guava, and indeed in quite a few other libraries as well.

Along with some minor additional code in VPack.java to deal with deserializing wildcard types e.g. if we try to deserialize into a list like List<? extends Foo> this works quite well.

This does also require a minor change in a couple of places in the java driver to cast the result coming back from this call, because java's type inference sucks. I suppose for the same reason this is also a backward incompatible change, and so this probably requires a major version bump. However, I've left the versions alone for now.

When trying to parse json containing array with multiple objects with null values parser fails with exception.

String json = "{\"values\": [ {\"a\": null}, {\"b\": null}]}";
VPackParser parser = new VPackParser.Builder().build();
parser.fromJson(json);

Results in:

Unexpected exception at position -1: null
	at com.arangodb.velocypack.VPackParser$VPackContentHandler.add(VPackParser.java:386)
	at com.arangodb.velocypack.VPackParser$VPackContentHandler.startObject(VPackParser.java:444)
	at org.json.simple.parser.JSONParser.parse(JSONParser.java:488)
	at org.json.simple.parser.JSONParser.parse(JSONParser.java:301)
	at org.json.simple.parser.JSONParser.parse(JSONParser.java:295)
	at com.arangodb.velocypack.VPackParser.fromJson(VPackParser.java:339)
	at com.arangodb.velocypack.VPackParser.fromJson(VPackParser.java:331)

I'm using java-velocypack version 1.0.9

The deserialization should provide a way to deserialize polymorphic lists.
Presumably for this we have to store information about the concrete implementation in vpack (like jackson with JsonTypeInfo).

It has add(final String attribute, final Byte value), so I would have expected a add(final Byte value) to be present, like there are for all other data types. addTagged(final long tag, final Byte value) is also missing.

With the latest update, the annotations @SerializezdName and @expose have been removed from this library and as far as I can tell, the functionality those provided no longer exists. Is there a migration process to move code that used those annotations to the latest version?

Version: 1.0.11

Test source code: https://gist.github.com/zqq90/2aa2e7aa6fdd7453e50d26cb0bc22b30

Exceptions like:

Caused by: java.lang.ClassCastException: sun.reflect.generics.reflectiveObjects.GenericArrayTypeImpl cannot be cast to java.lang.Class
	at com.arangodb.velocypack.VPack.addValue(VPack.java:854)
	at com.arangodb.velocypack.VPack.serializeField(VPack.java:824)
	...

Caused by: java.lang.ClassCastException: sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to java.lang.Class
	at com.arangodb.velocypack.VPack.addValue(VPack.java:854)
	at com.arangodb.velocypack.VPack.serializeField(VPack.java:824)
	...

Caused by: java.lang.ClassCastException: sun.reflect.generics.reflectiveObjects.TypeVariableImpl cannot be cast to java.lang.Class
	at com.arangodb.velocypack.VPack.getValue(VPack.java:560)
	at com.arangodb.velocypack.VPack.deserializeCollection(VPack.java:597)
	...

Consider the following (kotlin) code, using java-velocypack 2.2.1:

val slice = with(VPackBuilder(object : VPackBuilder.BuilderOptions {
	override fun isBuildUnindexedArrays() = true
	override fun isBuildUnindexedObjects() = true

	override fun setBuildUnindexedArrays(buildUnindexedArrays : Boolean) = throw NotImplementedError()
	override fun setBuildUnindexedObjects(buildUnindexedObjects : Boolean) = throw NotImplementedError()
}))
{
	add(ValueType.ARRAY)
	add(1)
	close()
	slice()
}

println(slice)
println(slice.toByteArray().toList())

Expected output would be (note that the byte values are base 10):

[1]
[19, 4, 49, 1]

Actual output is:

["(non-representable type)"]
[19, 4, 0, 1]

The output is as expected (albeit with a larger byte array) when isBuildUnindexedArrays() = false. The output is also as expected when not using small integer values.

The VPackBuilder seems to write the 1 correctly as 49 into its buffer, but fails to copy it to the correct position in VPackBuilder::closeCompactArrayOrObject.

Excuse the code (working with Clojure)
As a slice can contain a single element.

(-> (new VPackBuilder)
    (.add ValueType/OBJECT)
    (.add "foo" "bar")
    .close
    .slice
    (.get "foo"))

#object[com.arangodb.velocypack.VPackSlice 0x2b9072bd "\"bar\""]

Is there a canonical way of creating a single element slice?

(-> (new VPackBuilder)
    (.add ValueType/ARRAY)
    (.add "bar")
    .close
    .slice
    (.get 0))

#object[com.arangodb.velocypack.VPackSlice 0x1eb0779a "\"bar\""]

Arangodb content like {\n \"description\": \"String with new line\"\n} was ok for version 2.5.2.
Version 2.5.3 requires {\\n \"description\": \"String with new line\"\\n} otherwise Jackson ObjectMapper throws Exception with json String from VPackParser.toJson.
Is this change intentional or a bug?
See example v2.5.3 vs example v2.5.2

The VPackBuilder used while parsing the Json string is always created with the default options, so it is impossible to get a VPackSlice with unindexed arrays/objects.

Hi!

I saw that BigInteger is serialized as long and BigDecimal as double. But they can easily overflow long and double (that's why they exist ;)). Wouldn't it be better to serialize both as String?

Greetings,
Christian

Hi, can the json implementation be switched to Jackson? Jackson is standardized and used across the board in most projects. json-simple creates an extra dependency for us. Also as it's more heavily tested any issues, such as security are better looked after.

As an added bonus Jackon is faster. If size is an issue please look at jackson-jr.

Thanks!

When serializing an array of an abstract class or interface, a type hint should be added to the items, just like it's done for generic lists.