Java wrapper do not accept application/json requests

[RafalSkolasinski]

When Java wrapper (0.1 and 0.2) is deployed with executor one need to send requests as application-form data. See:

with executor

curl -s -X POST \
    -d 'json={"data": {"names": ["a", "b"], "ndarray": [[1.0, 2.0]]}}' \
    localhost:8003/seldon/seldon/compat-rest-java-02-executor/api/v1.0/predictions

with engine

curl -s -X POST -H 'Content-Type: application/json' \
    -d '{"data": {"names": ["a", "b"], "ndarray": [[1.0, 2.0]]}}' \
    localhost:8003/seldon/seldon/compat-rest-java-02-engine/api/v1.0/predictions

Error when trying:

curl -s -X POST -H 'Content-Type: application/json' \
    -d '{"data":{"names":["a","b"],"ndarray":[[1.0,2.0]]}}' \
    localhost:8003/seldon/seldon/compat-rest-java-02-executor/api/v1.0/predictions 
{
  "timestamp": 1585152322210,
  "status": 400,
  "error": "Bad Request",
  "exception": "org.springframework.web.bind.MissingServletRequestParameterException",
  "message": "Required String parameter 'json' is not present",
  "path": "/predict"
}

[ukclivecox]

We have an upgrade path for the wrapper and users should convert to latest
https://docs.seldon.io/projects/seldon-core/en/latest/reference/upgrading.html#wrapper-compatibility-table