Why am I getting a "401 Unauthorized" error in Maven?

I've had similar errors when trying to deploy a Gradle artefact to a Nexus Sonatype repository. You will get a 401 Unauthorized error if you supply the wrong credentials (password etc). You also get an error (and off the top of my head is also a 401) if you try to publish something to a releases repository and that version already exists in the repository. So you might find that by publishing from the command line it works, but then when you do it from a script it fails (because it didn't exist in the repository the first time around). Either publish using a different version number, or delete the old artefact on the server and republish.

The SNAPSHOTS repository (as opposed to the releases repository) allows you to overwrite a similarly numbered version, but your version number should have "-SNAPSHOT" at the end of it.

just change in settings.xml these as aliteralmind says:

  <server>
      <id>nexus-snapshots</id>
      <username>MY_SONATYPE_DOT_COM_USERNAME</username>
      <password>MY_SONATYPE_DOT_COM_PASSWORD</password>    
 </server>

you probably need to get the username / password from sonatype dot com.

I had put a not encrypted password in the settings.xml .

I tested the call with curl

curl -u username:password http://url/artifactory/libs-snapshot-local/com/myproject/api/1.0-SNAPSHOT/api-1.0-20160128.114425-1.jar --request PUT --data target/api-1.0-SNAPSHOT.jar 

and I got the error:

{
  "errors" : [ {
    "status" : 401,
    "message" : "Artifactory configured to accept only encrypted passwords but received a clear text password."
  } ]
}

I retrieved my encrypted password clicking on my artifactory profile and unlocking it.

One of the reasons for this error is when repositoryId is not specified or specified incorrectly. As mentioned already it should be the same as in section in settings.xml. Couple of hints... Run mvn with -e -X options and check the debug output. It will tell you which repositoryId it is using:

[DEBUG]   (f) offline = false
[DEBUG]   (f) packaging = exe
[DEBUG]   (f) pomFile = c:\temp\build-test\pom.xml
[DEBUG]   (f) project = MavenProject: org.apache.maven:standalone-pom:1 @ 
[DEBUG]   (f) repositoryId = remote-repository
[DEBUG]   (f) repositoryLayout = default
[DEBUG]   (f) retryFailedDeploymentCount = 1
[DEBUG]   (f) uniqueVersion = true
[DEBUG]   (f) updateReleaseInfo = false
[DEBUG]   (f) url = https://nexus.url.blah.com/...
[DEBUG]   (f) version = 13.1
[DEBUG] -- end configuration --

In this case it uses the default value "remote-repository", which means that something went wrong.

Apparently I have specified -DrepositoryID (note ID in capital) instead of -DrepositoryId.