[FIXED] How to add CometD 5x and above jars to Maven project

Issue

I’m not a Java developer, but I find myself having to update an old Maven Java command line project that uses a cometd 4x client library. Every since version 5x, cometd libraries inside the main Maven repo contain only pom.xml files, but no jar files (for instance https://repo1.maven.org/maven2/org/cometd/java/cometd-java-client/7.0.7/), so I cannot simply add this entry to my pom.xml:

<dependency>
    <groupId>org.cometd.java</groupId>
    <artifactId>cometd-java-client</artifactId>
    <version>7.0.7</version>
</dependency>

The cometd official site does provide a .tar.gz file with all the needed jars (https://download.cometd.org/), and in a folder hierarchy that resembles a maven repo, but I could not find instructions on how to use it properly.

The official documentation only focuses on server implementations which have a ton of extra dependencies (https://docs.cometd.org/current7/reference/#_deploying_your_cometd_application).

Can I add the contents of the .tar.gz file as a local maven repo or as a module of my current project? And how do I do that exactly? Right now I’m trying a solution form this answer (Can I add jars to Maven 2 build classpath without installing them?), but there are so many manual steps that I believe there must be a better way to do it.

Solution

Please follow the migration guide from 4.x to 5.x here (and also the other migration guides since you're jumping from 4.x to 7.x).

In particular, 4.x artifact cometd-java-client has been split since CometD 5.x into multiple different implementations that now you have to specify explicitly, for example cometd-java-client-http-jetty for the equivalent used in 4.x, or the new cometd-java-client-http-okhttp.

Answered By - sbordet
Answer Checked By - Clifford M. (JavaFixing Volunteer)