title: Maven ArtifactNotFoundException troubleshooting
body: <p><strong>Problem:</strong> I'm trying to get Google Protocol Buffers dependencies work. But with no result. Maven just can't pull any protocol buffers dependencies.</p>
  
  <p><strong>Question1:</strong> As I understand this dependency is absent in standard maven repositories, so I just need to indicate some extra repositories. <em>Am I right?</em> </p>
  
  <p><strong>Question2:</strong> <em>If answer to the first question is YES, than how can I get the url of that extra repository?</em> <a href="http://mvnrepository.com/artifact/com.google.protobuf/protobuf-java/2.5.0" rel="nofollow">Here</a>  is the reference to maven dependency.</p>
  
  <p><strong>Error:</strong></p>
  
  <pre><code>[ERROR] Plugin com.google.protobuf.tools:maven-protoc-plugin:0.3.2 or one of its dependencies could not be resolved: Failure to find com.google.protobuf.to
  ols:maven-protoc-plugin:jar:0.3.2 in http://repo.maven.apache.org/maven2 was cached in the local repository, resolution will not be reattempted until the u
  pdate interval of central has elapsed or updates are forced -&gt; [Help 1]
  org.apache.maven.plugin.PluginResolutionException: Plugin com.google.protobuf.tools:maven-protoc-plugin:0.3.2 or one of its dependencies could not be resol
  ved: Failure to find com.google.protobuf.tools:maven-protoc-plugin:jar:0.3.2 in http://repo.maven.apache.org/maven2 was cached in the local repository, res
  olution will not be reattempted until the update interval of central has elapsed or updates are forced
         .......
  Caused by: org.eclipse.aether.resolution.ArtifactResolutionException: Failure to find com.google.protobuf.tools:maven-protoc-plugin:jar:0.3.2 in http://rep
  o.maven.apache.org/maven2 was cached in the local repository, resolution will not be reattempted until the update interval of central has elapsed or update
  s are forced
  </code></pre>
  
  <p><strong>pom.xml:</strong></p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;project xmlns="http://maven.apache.org/POM/4.0.0"
           xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
           xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"&gt;
      &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
  
      &lt;groupId&gt;groupId&lt;/groupId&gt;
      &lt;artifactId&gt;JavaSockets&lt;/artifactId&gt;
      &lt;version&gt;1.0-SNAPSHOT&lt;/version&gt;
  
      &lt;dependencies&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;com.google.protobuf&lt;/groupId&gt;
              &lt;artifactId&gt;protobuf-java&lt;/artifactId&gt;
              &lt;version&gt;2.5.0&lt;/version&gt;
          &lt;/dependency&gt;
      &lt;/dependencies&gt;
  
      &lt;build&gt;
          &lt;plugins&gt;
              &lt;plugin&gt;
                  &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
                  &lt;artifactId&gt;maven-compiler-plugin&lt;/artifactId&gt;
                  &lt;version&gt;3.1&lt;/version&gt;
                  &lt;configuration&gt;
                      &lt;source&gt;1.7&lt;/source&gt;
                      &lt;target&gt;1.7&lt;/target&gt;
                  &lt;/configuration&gt;
              &lt;/plugin&gt;
              &lt;plugin&gt;
                  &lt;groupId&gt;com.google.protobuf.tools&lt;/groupId&gt;
                  &lt;artifactId&gt;maven-protoc-plugin&lt;/artifactId&gt;
                  &lt;version&gt;0.3.2&lt;/version&gt;
                  &lt;configuration&gt;
                      &lt;protocExecutable&gt;C:\Users\Clasik\Desktop\Java Sockets&lt;/protocExecutable&gt;
                  &lt;/configuration&gt;
                  &lt;executions&gt;
                      &lt;execution&gt;
                          &lt;goals&gt;
                              &lt;goal&gt;compile&lt;/goal&gt;
                              &lt;goal&gt;testCompile&lt;/goal&gt;
                          &lt;/goals&gt;
                      &lt;/execution&gt;
                  &lt;/executions&gt;
              &lt;/plugin&gt;
          &lt;/plugins&gt;
      &lt;/build&gt;
  &lt;/project&gt;
  
  
          ......
  Caused by: org.eclipse.aether.transfer.ArtifactNotFoundException: Failure to find com.google.protobuf.tools:maven-protoc-plugin:jar:0.3.2 in http://repo.ma
  ven.apache.org/maven2 was cached in the local repository, resolution will not be reattempted until the update interval of central has elapsed or updates ar
  e forced   
    ...............
  </code></pre>