Cannot make converter from byte[] to String

[magnusar]

The examples for how to use an OverrideConverter for Calendar objects, for example described here #359 works fine for us.

But I'm unable to make a converter work for the type byte[] that outputs it as a String. How can this be achieved? The following does not work:

OverrideConverter converter = new OverrideConverter();
converter.add("array[byte]", jsonString);
ModelConverters.addConverter(converter, true);

Our property looks like this:
@ApiModelProperty(value = "base64 encoded string", notes = "base64 string", required = true)
private byte[] myBytes;

We are using com.wordnik:swagger-jaxrs_2.11:1.3.10 in a Dropwizard project.

[webron]

Instead of using a converter, have you tried the following?

@ApiModelProperty(value = "base64 encoded string", dataType="string", notes = "base64 string", required = true)
private byte[] myBytes;

I'm not entirely sure it'll work with string, but if not, you can also try String or java.lang.String.

[magnusar]

Yes I've already tried that. It doesn't work. It produces a Scala match error "scala.MatchError: string (of class java.lang.String)"

(Using just byte in combination with dataType="string" works fine and the output is a string. It's the byte[] that I can't make work.)

[webron]

You've tried all 3 variants?
Also, not that it should matter, can you also try changing your dependency to swagger-jersey-jaxrs instead?

[webron]

Hmm, it looks like this is related to #334 unfortunately.
I'm not sure you can assign a converter to an array, but @fehguy will have to comment on that.

[magnusar]

Sorry, what are the three variants? Yeah I can try changing the dependency.

[webron]

Well, you can try string, String, or java.lang.String.

[fehguy]

I don't believe you can override datatypes in model properties, period.

[webron]

Theoretically, we allow it - https://github.com/wordnik/swagger-core/blob/master/modules/swagger-annotations/src/main/java/com/wordnik/swagger/annotations/ApiModelProperty.java#L67

[fehguy]

Yes, you can add the annotations, but I don't believe they're honored. I'd suggest checking the tests.

Per @webron's comment below, I was mistaken.

[webron]

Just tested it and it works fine. I've used @ApiModelProperty(dataType="string") on a getter of a long field and the specification came out as string.

@magnusar - if it doesn't work for you, could you please produce a test case I can check locally?

[magnusar]

@webron && @fehguy : I'm not surprised that the annotation worked for long -> String, since it worked for me with byte -> String. The problem is the array primitive. So if you can make anything primitive[] working (preferably byte[] since that is my case) that would probably solve it.

If I end up having to patch the code myself, do you please have any pointers as to how I would go about making a converter work for arrays of Java primitives? (I'm totally new to Scala...)

Thanx for the feeback.

[webron]

Okay, I did some further testing. The problem is not related with primitive arrays but rather with arrays or anything that translates to an array. The type can be a primitive or a class, and the array could be a java array or the collections we parse as arrays (List, Set...). And this is a bug the way I see it.

@fehguy - could you look into that please?

[fehguy]

it is impossible to support all overrides in this fashion. It's a string, and to read the annotation, we're instantiating the class. So "List[String]" is not only invalid syntax for java, but impossible to instantiate because List isn't a concrete class.

I suggest we document the behavior, add support for overrides in the property parsing, and start using concrete classes for overrides rather than string representations.

[webron]

With swagger-core 1.5 I don't think it's relevant anymore, but I'm not sure follow everything you say here.
I agree with the usage of concrete classes instead of a string (though it would be a problem with collections). But what is the actual problem with replacing a value type of array with another one?
Just to make sure we're on the same page, I'm referring to this:

@ApiModelProperty(dataType="string")
private byte[] myBytes;

vs

@ApiModelProperty(dataType="string")
private long date;

The first sample doesn't work, the second works fine.

[magnusar]

As an input to the discussion, when I look at the response body where we also have a byte[] it looks like this in the Swagger UI if I click the Model link:

MyClass {
anotherByteArray (array[byte]): base64 encoded byte array
}

So "array[byte]" is used as syntax at least in the output. I don't know if that's relevant but that's why I tried "converter.add("array[byte]", jsonString);" as stated in the issue.