Issue with returned data after POSTing a Order

[emma-aqua]

After migrating to the OpenAPI 3.0.1 JSON specifications (generated using openapi-generator-cli 7.23.0) (flags --global-property apiDocs=false,modelDocs=false,apiTests=false,modelTests=false) I am having an issue with the returned data from Tripletex (See stacktrace). The test Order here has one single OrderLine.

The order shows up in the Tripletex web-ui as expected.

`Exception in thread "AWT-EventQueue-0" com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Not a JSON Object: null
        at com.google.gson.Gson.fromJson(Gson.java:1238)
        at com.google.gson.Gson.fromJson(Gson.java:1137)
        at com.google.gson.Gson.fromJson(Gson.java:1107)
        at org.openapitools.client.JSON.deserialize(JSON.java:2763)
        at org.openapitools.client.ApiClient.deserialize(ApiClient.java:960)
        at org.openapitools.client.ApiClient.handleResponse(ApiClient.java:1178)
        at org.openapitools.client.ApiClient.execute(ApiClient.java:1102)
        at org.openapitools.client.api.OrderApi.orderPostWithHttpInfo(OrderApi.java:1558)
        at org.openapitools.client.api.OrderApi.orderPost(OrderApi.java:1538)`

[tlxtellef]

The problem you are encountering is most likely due to a combination of factors:

• Using Java which requires complete objects (no sparse objects, all fields present with some kind of value like null)
• GSON config for handling of null & not present values
• Every single field in the JSON can be filtered out (aka not present) due to fields filtering

Only the 2 first factors are ones you can change, of those the 2nd one (GSON) is the easier one to change. For that there are generally 2 alternatives: adjust GSON configuration to properly handle null & not present values, or switch to another JSON framework (for example Jackson).