Fix problem in the jetty-client-9.x which leading original listener reading empty content

[mei-zengxin]

Fix problem in the jetty-client-9.x which leading original listener reading empty content

• Add a unit test to verify that the fix works.
• Explain briefly why the bug exists and how to fix it.

when using jetty-client 9.x send async request, reponse body is always empty

because the onContent callback could not be executed

        request.send(new BufferingResponseListener() {
            @Override
            public void onComplete(Result result) {
                try { 
                    //this is always empty when use agent
                    byte[] responseBytes = getContent();
                    if (responseBytes == null || responseBytes.length == 0) {
                        System.out.println("responseBytes is empty");
                    }
                    System.out.println(new String(responseBytes, "UTF-8"));
                } catch (UnsupportedEncodingException e) {
                    throw new RuntimeException(e);
                }
            }
        });

• Update the CHANGES log.

[wu-sheng]

Why change this? Would this break preview compatibility?

[mei-zengxin]

because org.eclipse.jetty.client.api.Response.AsyncContentListener cound not be found in 9.1.x version
if the wrapper not implementing it, application will also get empty result when using jetty client 9.2.x or later,

by testing, it is compatible with preview version 9.1.0.v20131115
, 9.2.12.v20150709, 9.3.30.v20211001 and 9.4.55.v20240627

[wu-sheng]

If it doesn't exist in 9.1.0.v20131115, how do we make sure of compatibility? This doesn't make sense.

[wu-sheng]

You should fix CI, and add more versions of newly supported to verify.

[wu-sheng]

You should update the following test scenarios and expected files. add the async calling as you mentioned.

• https://github.com/apache/skywalking-java/tree/main/test/plugin/scenarios/jetty-scenario
• https://github.com/apache/skywalking-java/tree/main/test/plugin/scenarios/jetty-10.x-scenario
• https://github.com/apache/skywalking-java/tree/main/test/plugin/scenarios/jetty-11.x-scenario

[wu-sheng]

@mei-zengxin Are you still working on this?

[wu-sheng]

Close as no update.