Getting error while using jira cloud api from swagger

[David Smith]

Getting this error while using swagger generated as discussed in this URL, Could anyone please take a look and suggest any workaround for this? 

It would be a great help if you could help with this issue?
Attaching Stack Trace and possible reasons due to which it is being generated.

---

https://elmah.io/tools/stack-trace-formatter/80eb332a6f7a4fc7a65cb5c6a9ee7e1a

Basically, the discriminator being generated is empty, how to solve this?

return getClassByDiscriminator(
            classByDiscriminatorValue,
            getDiscriminatorValue(readElement, ""));

[Ben Kelley]

As mentioned by @Chandim Chatterjee this seems to be a known bug in swagger-codegen. https://github.com/swagger-api/swagger-codegen/issues/10196

I guess the solution for now is to use openapi-generator if this bug affects you, or else wait for the fix for swagger-codegen to be released.

[David Smith]

@Ben Kelley, Can you please help?

[Ben Kelley]

What URL/API are you accessing? It's hard to get any context here.

[Ben Kelley]

Also, it looks like you are running a test that is failing. I don't think you can run the generated tests without modification.

[David Smith]

What modification do I need to make, like added API token and userName getting data, but the problem occurs in deserialization of Data as swagger is creating multiple implementations, but doesn't give any discriminator.

[Ben Kelley]

Perhaps you could indicate what options you used to to generate your library, and give some sample code you are calling that is failing.

[David Smith]

Code Failing here while deserialization of data while trying to run Tests

public static GsonBuilder createGson() {
    GsonFireBuilder fireBuilder = new GsonFireBuilder()
      .registerTypeSelector(UserDetails.class, new TypeSelector<UserDetails>() {
        @Override
        public Class<? extends UserDetails> getClassForElement(JsonElement readElement) {
            Map<String, Class<? extends UserDetails>> classByDiscriminatorValue = new HashMap<>();
                classByDiscriminatorValue.put("AllOfAttachmentAuthor".toUpperCase(), AllOfAttachmentAuthor.class);
                classByDiscriminatorValue.put("AllOfChangelogAuthor".toUpperCase(), AllOfChangelogAuthor.class);
                classByDiscriminatorValue.put("AllOfCommentAuthor".toUpperCase(), AllOfCommentAuthor.class);
                classByDiscriminatorValue.put("AllOfCommentUpdateAuthor".toUpperCase(), AllOfCommentUpdateAuthor.class);
                classByDiscriminatorValue.put("AllOfEventNotificationUser".toUpperCase(), AllOfEventNotificationUser.class);
                classByDiscriminatorValue.put("AllOfFieldsAssignee".toUpperCase(), AllOfFieldsAssignee.class);
                classByDiscriminatorValue.put("AllOfWorklogAuthor".toUpperCase(), AllOfWorklogAuthor.class);
                classByDiscriminatorValue.put("AllOfWorklogUpdateAuthor".toUpperCase(), AllOfWorklogUpdateAuthor.class);
                classByDiscriminatorValue.put("UserDetails".toUpperCase(), UserDetails.class);
            return getClassByDiscriminator(
                        classByDiscriminatorValue,
                        getDiscriminatorValue(readElement, ""));
        }
      })

private static <T> Class<? extends T> getClassByDiscriminator(Map<String, Class<? extends T>> classByDiscriminatorValue, String discriminatorValue) {
    Class<? extends T> clazz = classByDiscriminatorValue.get(discriminatorValue.toUpperCase());
    if(null == clazz) {
        throw new IllegalArgumentException("cannot determine model class of name: <" + discriminatorValue + ">");
    }
    return clazz;
}

private static String getDiscriminatorValue(JsonElement readElement, String discriminatorField) {
    JsonElement element = readElement.getAsJsonObject().get(discriminatorField);
    if(null == element) {
        throw new IllegalArgumentException("missing discriminator field: <" + discriminatorField + ">");
    }
    return element.getAsString();
}

swagger-codegen generate \

    -i ./swagger-v3.v3.json \

    -l java \

    -o ~/src/jira-client

Config.json
{
"modelPackage": "com.spr.jira.rest.client.model",
"apiPackage": "com.spr.jira.rest.client.api",
"invokerPackage": "com.spr.jira.rest.client",
"library": "jersey2",
"groupId": "com.spr.jira.rest",
"artifactId": "client"
}

[David Smith]

Hi, anything else should I provide?

[Ben Kelley]

I get quite different code for the same config/command. I only see this method signature in client/JSON.java:

public static GsonBuilder createGson()

But the method I get looks like:

public static GsonBuilder createGson() {
    GsonFireBuilder fireBuilder = new GsonFireBuilder()
    ;
    return fireBuilder.createGsonBuilder();
}

I'm using swagger-codegen 3.0.16 and the latest swagger-v3.v3.json

[Chandim Chatterjee]

I got the same issue as OP and getting this exception whenever I try to fetch the changelog. @David Smith were you able to figure out this issue?

[Ben Kelley]

@Chandim Chatterjee how did you generate the source for your client? (e.g. which version of swagger-codegen, and did you use the latest published swagger spec) Can you confirm you're requesting this from a Jira Cloud site (and not Server or Data Centre)? (FWIW I can't see the original stack trace any more, so I can't see the actual error any more.)

[Chandim Chatterjee]

@Ben Kelley 

I used the spec available on this site: https://developer.atlassian.com/cloud/jira/platform/rest/v3/intro/ and my swagger-codegen version is 3.0.41.

This is the config I used in generating the client in java:

{

    "modelPackage": "com.squareup.jira.cloud.rest.client.model",

    "apiPackage": "com.squareup.jira.cloud.rest.client.api",

    "invokerPackage": "com.squareup.jira.cloud.rest.client",

    "library": "retrofit2",

    "groupId": "com.squareup.jira.cloud.rest",

    "artifactId": "client"

}

This is the error I get:

missing discriminator field: <>
java.lang.IllegalArgumentException: 
at com.squareup.jira.cloud.rest.client.JSON.getDiscriminatorValue(JSON.java:983)
at com.squareup.jira.cloud.rest.client.JSON$53.getClassForElement(JSON.java:387)
at io.gsonfire.gson.TypeSelectorTypeAdapterFactory$TypeSelectorTypeAdapter.read(TypeSelectorTypeAdapterFactory.java:65)
at io.gsonfire.gson.NullableTypeAdapter.read(NullableTypeAdapter.java:36)
at io.gsonfire.gson.HooksTypeAdapter.deserialize(HooksTypeAdapter.java:86)
at io.gsonfire.gson.HooksTypeAdapter.read(HooksTypeAdapter.java:54)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$1.readIntoField(ReflectiveTypeAdapterFactory.java:212)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$FieldReflectionAdapter.readField(ReflectiveTypeAdapterFactory.java:433)
at com.google.gson.internal.bind.ReflectiveTypeAdapterFactory$Adapter.read(ReflectiveTypeAdapterFactory.java:393)
at retrofit2.converter.gson.GsonResponseBodyConverter.convert(GsonResponseBodyConverter.java:40)
at retrofit2.converter.gson.GsonResponseBodyConverter.convert(GsonResponseBodyConverter.java:27)
at retrofit2.OkHttpCall.parseResponse(OkHttpCall.java:243)
at retrofit2.OkHttpCall.execute(OkHttpCall.java:204)
...

Looking at the auto-generated code, I see a similar error as what @David Smith found. 

I believe this may be an existing error in swagger-codegen according to this bug which has been only recently fixed: https://github.com/swagger-api/swagger-codegen/issues/10196

[Ben Kelley]

Great find @Chandim Chatterjee . I agree - it's probably the swagger-codegen bug you linked. There's a comment there that openapi-generator works OK, or else I guess you could wait for the bug fix.

[David Smith]

Hi, Could anyone help in this, or mention what more context should I provide ?

[Jon Martin Solaas]

Using openapi codegen (java jar version) instead of swagger-codegen produced code that seems to work fine for me, getting my worklog hours mostly. Have not tested everything, but at least no up-front hacking required.

Switch the -l java option with -g java, other options  in use here are the same.

Used Java 8 to build it.