Maven dependencies are failing with a 501 error

Question

Recently Maven build jobs running in Jenkins are failing with the below exception saying that they couldn't pull dependencies from Maven Central and should use HTTPS. I'm not sure how to change the requests from HTTP to HTTPS. Could someone guide me on this matter?

[ERROR] Unresolveable build extension:
Plugin org.apache.maven.wagon:wagon-ssh:2.1 or one of its dependencies could not be resolved:
Failed to collect dependencies for org.apache.maven.wagon:wagon-ssh:jar:2.1 ():
Failed to read artifact descriptor for org.apache.maven.wagon:wagon-ssh:jar:2.1:
Could not transfer artifact org.apache.maven.wagon:wagon-ssh:pom:2.1 from/to central (http://repo.maven.apache.org/maven2):
Failed to transfer file: http://repo.maven.apache.org/maven2/org/apache/maven/wagon/wagon-ssh/2.1/wagon-ssh-2.1.pom.
Return code is: 501, ReasonPhrase:HTTPS Required. -> [Help 2]

Waiting for Jenkins to finish collecting data[ERROR]
Plugin org.apache.maven.plugins:maven-clean-plugin:2.4.1 or one of its dependencies could not be resolved:
Failed to read artifact descriptor for org.apache.maven.plugins:maven-clean-plugin:jar:2.4.1:
Could not transfer artifact org.apache.maven.plugins:maven-clean-plugin:pom:2.4.1 from/to central (http://repo.maven.apache.org/maven2):
Failed to transfer file: http://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-clean-plugin/2.4.1/maven-clean-plugin-2.4.1.pom.
Return code is: 501 , ReasonPhrase:HTTPS Required. -> [Help 1]

Answer 1

The reason for the observed error is explained in Central 501 HTTPS Required

Effective January 15, 2020, The Central Repository no longer supports insecure communication over plain HTTP and requires that all requests to the repository are encrypted over HTTPS.

It looks like latest versions of Maven (tried with 3.6.0, 3.6.1) are already using the HTTPS URL by default.

Here are the dates when the major repositories will switch:

Your Java builds might break starting January 13th (if you haven't yet switched repo access to HTTPS)

Update: Seems like from maven 3.2.3 maven central is accessed via HTTPS See https://stackoverflow.com/a/25411658/5820670

Maven Change log (http://maven.apache.org/docs/3.2.3/release-notes.html)

Answer 2

I am facing the same problem. There are two solutions that I tried, and both works fine for me.

• Update the Maven version repository (Maven version >= 3.2.3)
• Restrict the current Maven version to use HTTPS links.

Update the Maven version repository:

Download the Apache Maven binary that includes the default https addresses (Apache Maven 3.6.3 binary). And open the Options dialog window in tools of NetBeans menu bar (Java Maven Dialog View). And select browse option in Maven Home List Box (Maven Home List Box View). After adding the Apache Maven newly downloaded version (Updated Maven Home List Box View), the project builds and runs successfully.

Restrict the current Maven version to use HTTPS links:

Include the following code in pom.xml of your project.

<project>
      ...
    <pluginRepositories>
        <pluginRepository>
            <id>central</id>
            <name>Central Repository</name>
            <url>https://repo.maven.apache.org/maven2</url>
            <layout>default</layout>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
            <releases>
                <updatePolicy>never</updatePolicy>
            </releases>
        </pluginRepository>
    </pluginRepositories>
    <repositories>
        <repository>
            <id>central</id>
            <name>Central Repository</name>
            <url>https://repo.maven.apache.org/maven2</url>
            <layout>default</layout>
            <snapshots>
                <enabled>false</enabled>
            </snapshots>
        </repository>
    </repositories>
</project>