title: MAVEN error while downloading dl4j examples
body: <p>Before I ask the question let me just say that I'm completely new to DL4J, maven and java, so please bear with my stupid question.</p>
  
  <p>I'm trying to install the dl4j-examples using <code>mvn clean install</code> command but I get the following error:</p>
  
  <pre><code>[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.5.1:compile (default-compile) on project datavec-examples: Fatal error compiling: java.lang.NoClassDefFoundError: com/sun/tools/javac/file/BaseFileObject: com.sun.tools.javac.file.BaseFileObject -&gt; [Help 1]
  </code></pre>
  
  <p>Now what I don't get is whether I'm getting this error because of java or maven?</p>
  
  <p>The full stack error is:</p>
  
  <pre><code>[ERROR] No goals have been specified for this build. You must specify a valid lifecycle phase or a goal in the format &lt;plugin-prefix&gt;:&lt;goal&gt; or &lt;plugin-group-id&gt;:&lt;plugin-artifact-id&gt;[:&lt;plugin-version&gt;]:&lt;goal&gt;. Available lifecycle phases are: validate, initialize, generate-sources, process-sources, generate-resources, process-resources, compile, process-classes, generate-test-sources, process-test-sources, generate-test-resources, process-test-resources, test-compile, process-test-classes, test, prepare-package, package, pre-integration-test, integration-test, post-integration-test, verify, install, deploy, pre-clean, clean, post-clean, pre-site, site, post-site, site-deploy. -&gt; [Help 1]
  org.apache.maven.lifecycle.NoGoalSpecifiedException: No goals have been specified for this build. You must specify a valid lifecycle phase or a goal in the format &lt;plugin-prefix&gt;:&lt;goal&gt; or &lt;plugin-group-id&gt;:&lt;plugin-artifact-id&gt;[:&lt;plugin-version&gt;]:&lt;goal&gt;. Available lifecycle phases are: validate, initialize, generate-sources, process-sources, generate-resources, process-resources, compile, process-classes, generate-test-sources, process-test-sources, generate-test-resources, process-test-resources, test-compile, process-test-classes, test, prepare-package, package, pre-integration-test, integration-test, post-integration-test, verify, install, deploy, pre-clean, clean, post-clean, pre-site, site, post-site, site-deploy.
      at org.apache.maven.lifecycle.internal.LifecycleStarter.execute (LifecycleStarter.java:97)
      at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:309)
      at org.apache.maven.DefaultMaven.doExecute (DefaultMaven.java:194)
      at org.apache.maven.DefaultMaven.execute (DefaultMaven.java:107)
      at org.apache.maven.cli.MavenCli.execute (MavenCli.java:955)
      at org.apache.maven.cli.MavenCli.doMain (MavenCli.java:290)
      at org.apache.maven.cli.MavenCli.main (MavenCli.java:194)
      at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
      at jdk.internal.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)
      at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
      at java.lang.reflect.Method.invoke (Method.java:564)
      at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced (Launcher.java:289)
      at org.codehaus.plexus.classworlds.launcher.Launcher.launch (Launcher.java:229)
      at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode (Launcher.java:415)
      at org.codehaus.plexus.classworlds.launcher.Launcher.main (Launcher.java:356)
  [ERROR]
  [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/NoGoalSpecifiedException
  </code></pre>
  
  <p>I'm running following versions of java and maven on windows 10 (64 bit)</p>
  
  <pre><code>Picked up _JAVA_OPTIONS: -Xmx512M
  java version "9.0.4"
  Java(TM) SE Runtime Environment (build 9.0.4+11)
  Java HotSpot(TM) 64-Bit Server VM (build 9.0.4+11, mixed mode)
  Apache Maven 3.5.2 (138edd61fd100ec658bfa2d307c43b76940a5d7d; 2017-10-18T12:58:13+05:00)
  Maven home: C:\apache-maven-3.5.2-bin\apache-maven-3.5.2
  Java version: 9.0.4, vendor: Oracle Corporation
  Java home: C:\Progra~1\Java\jdk-9.0.4
  Default locale: en_US, platform encoding: Cp1252
  OS name: "windows 10", version: "10.0", arch: "amd64", family: "windows"
  </code></pre>
  
  <p>Here's a screen shot for my environment variables:</p>
  
  <p><a href="https://i.stack.imgur.com/j51kk.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/j51kk.jpg" alt="enter image description here"></a></p>
  
  <p><a href="https://i.stack.imgur.com/mMDc3.jpg" rel="noreferrer"><img src="https://i.stack.imgur.com/mMDc3.jpg" alt="enter image description here"></a></p>