Maven Build Failure -- DependencyResolutionException

Question

I'm installing a package that has Maven dependency and get a DependencyResolutionException when I try to clean it. After cloning it, I navigate to the directory and run the following to install it with no error:

mvn install:install-file -Dfile=./lib/massbank.jar -DgroupId=massbank  -DartifactId=massbank -Dversion=1.0 -Dpackaging=jar
mvn install:install-file -Dfile=./lib/metfusion.jar -DgroupId=de.ipbhalle.msbi  -DartifactId=metfusion -Dversion=1.0 -Dpackaging=jar

Then:

mvn clean package 

with the following console output:

[INFO] Scanning for projects...
[INFO] 
[INFO] --------------------< MassBank2NIST:MassBank2NIST >---------------------
[INFO] Building MassBank2NIST 0.0.2-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  0.450 s
[INFO] Finished at: 2021-04-07T01:08:28-04:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal on project MassBank2NIST: Could not resolve dependencies for project MassBank2NIST:MassBank2NIST:jar:0.0.2-SNAPSHOT: Failed to collect dependencies at edu.ucdavis.fiehnlab.splash:core:jar:1.8: Failed to read artifact descriptor for edu.ucdavis.fiehnlab.splash:core:jar:1.8: Could not transfer artifact edu.ucdavis.fiehnlab.splash:core:pom:1.8 from/to maven-default-http-blocker (http://0.0.0.0/): Blocked mirror for repositories: [EBI (http://www.ebi.ac.uk/intact/maven/nexus/content/repositories/ebi-repo/, default, releases+snapshots), releases (http://gose.fiehnlab.ucdavis.edu:55000/content/groups/public, default, releases+snapshots)] -> [Help 1]
[ERROR] 
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR] 
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/DependencyResolutionException

I can post the output of the debug logging switch if necessary, but it's quite long. I can also post the pom.xml, however it refers to the repositories as required from what I can tell.

I've searched for similar posts, but none seem to contain the same series of errors or similar. Can someone help me decipher these errors?

Thanks!

Answer 1

You don't have to downgrade Maven. What happens here is that since 3.8.1, Maven comes with a default configuration to block all HTTP (insecure) repositories. The best way would be to upgrade your repositories and make them secure (HTTPS).

However, you can tell Maven to allow downloading from your insecure repository by adding this mirror to your ~/.m2/settings.xml:

<mirror>
  <id>insecure-repo</id>
  <mirrorOf>external:http:*</mirrorOf>
  <url>http://www.ebi.ac.uk/intact/maven/nexus/content/repositories/ebi-repo/</url>
  <blocked>false</blocked>
</mirror>

Setting blocked to false will fix your issue. Note that above snippet assumes that the repository at www.ebi.ac.uk mirrors all insecure HTTP repositories (which is what external:http:* means).

You can also unblock individual repositories. For example, the JasperSoft repository is insecure, I unblock it with:

<mirror>
  <id>jaspersoft-third-party-mirror</id>
  <mirrorOf>jaspersoft-third-party</mirrorOf>
  <url>http://jaspersoft.jfrog.io/jaspersoft/third-party-ce-artifacts/</url>
  <blocked>false</blocked>
</mirror>

Answer 2

If you do not have access to ~/.m2/settings.xml because your build is handled by cloud CI/CD or you want to share this solution with your team members. The best way is to create your own maven setting file in the project.

1. Create .mvn folder in your project.
2. Create custom-settings.xml file inside .mvn folder with such content (in this example we unblock http connection for releases.java.net mirror):

<settings xmlns="http://maven.apache.org/SETTINGS/1.2.0"
          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
          xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.2.0 http://maven.apache.org/xsd/settings-1.2.0.xsd">
    <mirrors>
        <mirror>
            <id>releases-java-net-http-unblocker</id>
            <mirrorOf>releases.java.net</mirrorOf>
            <name>releases.java.net</name>
            <url>http://maven.java.net/content/repositories/releases/</url>
            <blocked>false</blocked>
        </mirror>
    </mirrors>
</settings>

3. Create maven.config file inside .mvn folder with such content:

--settings ../.mvn/custom-settings.xml

Or you can just run mvn clean install --settings .mvn/custom-settings.xml.

Answer 3

Open file ${MAVEN_HOME}/conf/settings.xml

And Comment these lines.

<mirror>
    <id>maven-default-http-blocker</id>
    <mirrorOf>external:http:*</mirrorOf>
    <name>Pseudo repository to mirror external repositories initially using HTTP.</name>
    <url>http://0.0.0.0/</url>
    <blocked>false</blocked>
</mirror>