Return ContentType of "application/json" instead of "text/plain"

[yorondevops]

Override the ECSLayout parent class's (org.apache.logging.log4j.core.layout.AbstractStringLayout line 222) "getContentType()" function which always returns text/plain, so that it returns the ECS-appropriate application/json instead.

This change adds support for use of the ECS Layout in conjunction with the log4j2 HTTP #Appender

Usage of the layout's "getContentType()" function can be seen on line 89 of the HttpURLConnectionManager class, in the "send()" function ,which decides the Content-Type header the logs will be sent with.

This PR is to help close #89

[cla-checker-service]

💚 CLA has been signed

[apmmachine]

💚 Build Succeeded

Expand to view the summary

Build stats

• Build Cause: [Started by user Felix Barnsteiner, Replayed #3]

• Start Time: 2020-08-26T07:00:05.255+0000

• Duration: 7 min 49 sec

Test stats 🧪

Test	Results
Failed	0
Passed	104
Skipped	4
Total	108

[yorondevops]

Hi, I signed the "Contributor Agreement", any idea how I can get the checks to run again?

[felixbarny]

I have re-run the check. All good now!

[yorondevops]

Looks like the Jenkins job failed because I placed the function in the nested .Builder class instead of the ecslayout class,
fixed it

[yorondevops]

Looks like the maven build is failing now because of connectivity issues?
09:47:59 [ERROR] Failed to execute goal org.codehaus.mojo:license-maven-plugin:1.19:update-file-header (first) on project ecs-logging-java-parent: Execution first of goal org.codehaus.mojo:license-maven-plugin:1.19:update-file-header failed: Plugin org.codehaus.mojo:license-maven-plugin:1.19 or one of its dependencies could not be resolved: Failed to collect dependencies at org.codehaus.mojo:license-maven-plugin:jar:1.19 -> org.apache.maven:maven-plugin-api:jar:3.0 -> org.sonatype.sisu:sisu-inject-plexus:jar:1.4.2: Failed to read artifact descriptor for org.sonatype.sisu:sisu-inject-plexus:jar:1.4.2: Could not transfer artifact org.sonatype.sisu.inject:guice-plexus:pom:1.4.2 from/to central (https://repo.maven.apache.org/maven2): Connection reset -> [Help 1]

[felixbarny]

I ran the tests again and now it succeeded. Seemed to be a transient networking issue.

[yorondevops]

@felixbarny, thanks for all the help! When can i expect to see a new release with this fix?

[felixbarny]

Here you go: https://github.com/elastic/ecs-logging-java/releases/tag/v0.5.1