As of January 15, 2020 I am receiving the following responses upon making requests to The Central Repository:
Requests to http://repo1.maven.org/maven2/ return a 501 HTTPS Required status and a body:
501 HTTPS Required. Use https://repo1.maven.org/maven2/ More information at https://links.sonatype.com/central/501-https-required
Requests to http://repo.maven.apache.org/maven2/ return a 501 HTTPS Required status and a body:
501 HTTPS Required. Use https://repo.maven.apache.org/maven2/ More information at https://links.sonatype.com/central/501-https-required
How do I satisfy this requirement so that I can regain access to Central?
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.
If you're receiving this error, then you need to replace all URL references to Maven Central with their canonical HTTPS counterparts:
Replace http://repo1.maven.org/maven2/ with https://repo1.maven.org/maven2/
Replace http://repo.maven.apache.org/maven2/ with https://repo.maven.apache.org/maven2/
If for any reason your environment cannot support HTTPS, you have the option of using our dedicated insecure endpoint at http://insecure.repo1.maven.org/maven2/
For further context around the move to HTTPS, please see https://blog.sonatype.com/central-repository-moving-to-https.