[Java][jersey2] Fix logging for jersey2 (Java6)

[SergeyLyakhov]

PR checklist

[+] Read the contribution guidelines.
[+] Ran the shell script under ./bin/ to update Petstore sample so that CIs can verify the change. (For instance, only need to run ./bin/{LANG}-petstore.sh and ./bin/security/{LANG}-petstore.sh if updating the {LANG} (e.g. php, ruby, python, etc) code generator or {LANG} client's mustache templates). Windows batch files can be found in .\bin\windows\.
[-] Filed the PR against the correct branch: 3.0.0 branch for changes related to OpenAPI spec 3.0. Default: master.
Committed it into master branch, because expect this fix in 2.4.0. May create PR for 3.0 as well.

[+] Copied the technical committee to review the pull request if your PR is targeting a particular programming language.
@bbdouglas @JFCote @sreeshas @jfiala @lukoyanov @cbornet @wing328

Description of the PR

Jersey 2.6 (used with Java6) doesn't support LoggingFeature (fix SHA-1: 2d19776

• Merge branch 'mobreza-jersey-logging-deprecated' ).
  This change reverts to the old logging logic for Jersey2 + java6.

[SergeyLyakhov]

@wing328
This is one of fixes required for PR #7060 to pass test checks (other build issues are listed in #7060).
However I don't understand how this PR test was completed successfully, while #7060 - not.

[SergeyLyakhov]

@wing328
Also, do not understand how such fixes will be migrated to other branches. I suppose it is not possible to merge/cherry-pick changes in samples automatically. Should I perform any additional steps to add such changes into 2.4.0/3.0.0 branches?

[wing328]

@SergeyLyakhov We'll sync the change in master to those branches (2.4.0, 3.0.0) later

[wing328]

Please align this line properly by removing 2 spaces.

[SergeyLyakhov]

Fixed.

[wing328]

@SergeyLyakhov thanks again for the PR. When I tried to test samples/client/petstore/java/jersey2-java6 with Java6, I got the following errors:

0.24s$ cd samples/client/petstore/java/jersey2-java6/ && mvn test
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/apache/maven/cli/MavenCli : Unsupported major.minor version 51.0
	at java.lang.ClassLoader.defineClass1(Native Method)
	at java.lang.ClassLoader.defineClass(ClassLoader.java:648)
	at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
	at java.net.URLClassLoader.defineClass(URLClassLoader.java:272)
	at java.net.URLClassLoader.access$000(URLClassLoader.java:68)
	at java.net.URLClassLoader$1.run(URLClassLoader.java:207)

Ref: https://travis-ci.org/swagger-api/swagger-codegen/builds/327592947

Did you get similar result when running mvn test locally in your Java6 environment?

[SergeyLyakhov]

@wing328
This is byte code incompatibility version error.
Probably it occurred because you run mvn test with JRE6 (this is correct for test env), but project was built with more major version of JDK (7/8/9).
There are source|target parameters in javac / maven-compiler-plugin - https://stackoverflow.com/questions/15492948/javac-source-and-target-options.
In jersey2 project for "java6" it is 1.7 (both source and target).
"source" should be changed from 1.7 to 1.6 (for "java6") in pom and gradle (sbt script missed these settings).
"target" should be either changed in same way, or removed (in this case default version of javac will be used). If target removed - you need compile and test "java6" with the same version of JDK.

Will update PR tomorrow if you agree with proposed changes.

[wing328]

@SergeyLyakhov I forgot to mention that I did update the pom to use 1.6: https://github.com/swagger-api/swagger-codegen/blob/SergeyLyakhov-bugfix/jersey2-java6-logging/samples/client/petstore/java/jersey2-java6/pom.xml#L141-L142

[wing328]

@SergeyLyakhov I've merged your fix into master.

If you later can find a way to make it work with mvn test, please file another PR.