I installed nexus repository manager 3 in my system. I configured maven2 proxy repository, when i tried to clean pom.xml file using 'mvn clean' command, I am getting below error.
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------< com.sample.app:nexus-proxy-test >-------------------
[INFO] Building nexus-proxy-test 1.0-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
Downloading from nexus: http://localhost:8081/repository/maven-proxy-test/org/apache/maven/plugins/maven-clean-plugin/2.5/maven-clean-plugin-2.5.pom
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 0.377 s
[INFO] Finished at: 2019-10-03T19:04:32+05:30
[INFO] ------------------------------------------------------------------------
[ERROR] Plugin org.apache.maven.plugins:maven-clean-plugin:2.5 or one of its dependencies could not be resolved: Failed to read artifact descriptor for org.apache.maven.plugins:maven-clean-plugin:jar:2.5: Could not transfer artifact org.apache.maven.plugins:maven-clean-plugin:pom:2.5 from/to nexus (http://localhost:8081/repository/maven-proxy-test/): Not authorized -> [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/PluginResolutionException
Error stack trace looks like below.
Caused by: org.apache.maven.wagon.authorization.AuthorizationException: Not authorized
at org.apache.maven.wagon.providers.http.wagon.shared.AbstractHttpClientWagon.resourceExists (AbstractHttpClientWagon.java:838)
at org.apache.maven.wagon.providers.http.wagon.shared.AbstractHttpClientWagon.resourceExists (AbstractHttpClientWagon.java:809)
at org.eclipse.aether.transport.wagon.WagonTransporter$PeekTaskRunner.run (WagonTransporter.java:512)
at org.eclipse.aether.transport.wagon.WagonTransporter.execute (WagonTransporter.java:435)
at org.eclipse.aether.transport.wagon.WagonTransporter.peek (WagonTransporter.java:406)
at org.eclipse.aether.connector.basic.BasicRepositoryConnector$PeekTaskRunner.runTask (BasicRepositoryConnector.java:390)
at org.eclipse.aether.connector.basic.BasicRepositoryConnector$TaskRunner.run (BasicRepositoryConnector.java:364)
at org.eclipse.aether.util.concurrency.RunnableErrorForwarder$1.run (RunnableErrorForwarder.java:75)
at org.eclipse.aether.connector.basic.BasicRepositoryConnector$DirectExecutor.execute (BasicRepositoryConnector.java:644)
at org.eclipse.aether.connector.basic.BasicRepositoryConnector.get (BasicRepositoryConnector.java:262)
at org.eclipse.aether.internal.impl.DefaultArtifactResolver.performDownloads (DefaultArtifactResolver.java:499)
at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolve (DefaultArtifactResolver.java:401)
at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolveArtifacts (DefaultArtifactResolver.java:229)
at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolveArtifact (DefaultArtifactResolver.java:207)
at org.apache.maven.repository.internal.DefaultArtifactDescriptorReader.loadPom (DefaultArtifactDescriptorReader.java:240)
at org.apache.maven.repository.internal.DefaultArtifactDescriptorReader.readArtifactDescriptor (DefaultArtifactDescriptorReader.java:171)
at org.eclipse.aether.internal.impl.DefaultRepositorySystem.readArtifactDescriptor (DefaultRepositorySystem.java:255)
at org.apache.maven.plugin.internal.DefaultPluginDependenciesResolver.resolve (DefaultPluginDependenciesResolver.java:106)
at org.apache.maven.plugin.internal.DefaultMavenPluginManager.getPluginDescriptor (DefaultMavenPluginManager.java:182)
at org.apache.maven.plugin.internal.DefaultMavenPluginManager.getMojoDescriptor (DefaultMavenPluginManager.java:286)
at org.apache.maven.plugin.DefaultBuildPluginManager.getMojoDescriptor (DefaultBuildPluginManager.java:244)
at org.apache.maven.lifecycle.internal.DefaultLifecycleExecutionPlanCalculator.setupMojoExecution (DefaultLifecycleExecutionPlanCalculator.java:169)
at org.apache.maven.lifecycle.internal.DefaultLifecycleExecutionPlanCalculator.setupMojoExecutions (DefaultLifecycleExecutionPlanCalculator.java:154)
at org.apache.maven.lifecycle.internal.DefaultLifecycleExecutionPlanCalculator.calculateExecutionPlan (DefaultLifecycleExecutionPlanCalculator.java:130)
at org.apache.maven.lifecycle.internal.DefaultLifecycleExecutionPlanCalculator.calculateExecutionPlan (DefaultLifecycleExecutionPlanCalculator.java:144)
at org.apache.maven.lifecycle.internal.builder.BuilderCommon.resolveBuildPlan (BuilderCommon.java:97)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:111)
at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject (LifecycleModuleBuilder.java:81)
at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build (SingleThreadedBuilder.java:56)
at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:128)
at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:305)
at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:192)
at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:105)
at org.apache.maven.cli.MavenCli.execute (MavenCli.java:956)
at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:288)
at org.apache.maven.cli.MavenCli.main (MavenCli.java:192)
at sun.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke (Method.java:498)
at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:282)
at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:225)
at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:406)
at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:347)
This is authorization issue. Open settings.xml file from folder where maven is installed and correct the user ID and password. It should solve your problem.
Jar is not getting downloaded because of incorrect passwords.