Query parameter encoding has changed in Helidon 4, helidon-connector related

[jvissers]

Environment Details

• Helidon Version: 4.0.2
• Helidon MP
• JDK version: Java HotSpot(TM) 64-Bit Server VM (build 21.0.1+12-LTS-29, mixed mode, sharing)
• OS: Ubuntu 23.10

---

Problem Description

We are observing a change in the way which Helidon 4 encodes query parameters. This seems to be related to changed implementation in Helidon 4 connector.

Given the following:

        try (var r = target.path("severitylevels")
                .queryParam("q", "code.like('OIDECS_2658')")
                .queryParam("order", "description desc, audit.createdBy asc")
                .request()
                .get()) {

Helidon 3 encodes query parameters as:

description desc, audit.createdBy asc

Whereas Helidon 4 results in:

description+desc,+audit.createdBy+asc

Steps to reproduce

Some reference material (thanks for @ljnelson for digging that up)

here's 4.0.2 where the connector translates to WebClient-speak: https://github.com/helidon-io/helidon/blob/4.0.2/jersey/connector/src/main/java/io/helidon/jersey/connector/HelidonConnector.java#L148-L157

here's where the 3.2.5 version does it: https://github.com/helidon-io/helidon/blob/3.2.5/jersey/connector/src/main/java/io/helidon/jersey/connector/HelidonConnector.java#L137-L174
HelidonConnector.java