title: Spring Project - Classworlds Configuration not specified
body: <p>i'm new to Spring and Maven development and i'm making the example guides at: <a href="https://spring.io/guides" rel="nofollow">https://spring.io/guides</a>.</p>
  
  <p>In fact i'm trying to make a jar file with eclipse.</p>
  
  <p>The guide im following is this one: <a href="https://spring.io/guides/gs/device-detection/" rel="nofollow">https://spring.io/guides/gs/device-detection/</a></p>
  
  <p><strong>INFORMATION:</strong></p>
  
  <p><strong>System:</strong> Windows 8.1 (x64) - i5-62000U @ 2.30GHz</p>
  
  <p><strong>Im behind a proxy</strong> - Its all set up and eclipse handles all dependencies succefully.</p>
  
  <p><strong>Eclipse:</strong> JEE Mars 2 (version 4.5.2)</p>
  
  <p><strong>Java</strong>: JDK 1.8.0_77</p>
  
  <p><strong>JRE</strong>:  JRE 1.8.0_77</p>
  
  <p><strong>Maven:</strong> 3.3.9</p>
  
  <p><strong>M2E</strong>: It's installed in my eclipse (comes with JEE version).</p>
  
  <p><strong>STS</strong>: i'm not using Spring Tool Suite Eclipse, only Clean JEE Eclipse.</p>
  
  <p><strong>Environment variables:</strong> JAVA_HOME, M2_HOME are set up and next i put my path.</p>
  
  <p><strong>Windows PATH:</strong></p>
  
  <pre><code>C:\ProgramData\Oracle\Java\javapath;C:\Program Files (x86)\Intel\iCLS Client\;C:\Program Files\Intel\iCLS Client\;%SystemRoot%\system32;%SystemRoot%;%SystemRoot%\System32\Wbem;%SYSTEMROOT%\System32\WindowsPowerShell\v1.0\;C:\Program Files\Intel\WiFi\bin\;C:\Program Files\Common Files\Intel\WirelessCommon\;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files\Intel\Intel(R) Management Engine Components\DAL;C:\Program Files (x86)\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files\Intel\Intel(R) Management Engine Components\IPT;C:\Program Files (x86)\OpenVPN\bin;C:\Program Files (x86)\Skype\Phone\;C:\Progra~1\apache-maven-3.3.9\bin;C:\Program Files\Java\jdk1.8.0_77\bin
  </code></pre>
  
  <p><strong>Context:</strong></p>
  
  <p>I have created the project using the skip arcthetype selection and declare it clean with all the dependencies (following the example).</p>
  
  <p><strong>POM:</strong></p>
  
  <pre><code>&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;parent&gt;
      &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
      &lt;artifactId&gt;spring-boot-starter-parent&lt;/artifactId&gt;
      &lt;version&gt;1.3.3.RELEASE&lt;/version&gt;
    &lt;/parent&gt;
    &lt;groupId&gt;org.springframework&lt;/groupId&gt;
    &lt;artifactId&gt;gs-device-detection&lt;/artifactId&gt;
    &lt;version&gt;0.1.0&lt;/version&gt;
  
    &lt;dependencies&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-starter-web&lt;/artifactId&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.mobile&lt;/groupId&gt;
              &lt;artifactId&gt;spring-mobile-device&lt;/artifactId&gt;
          &lt;/dependency&gt;
      &lt;/dependencies&gt;
  
      &lt;properties&gt;
          &lt;java.version&gt;1.8&lt;/java.version&gt;
      &lt;/properties&gt;
  
  
      &lt;build&gt;
          &lt;plugins&gt;
              &lt;plugin&gt;
                  &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
                  &lt;artifactId&gt;spring-boot-maven-plugin&lt;/artifactId&gt;
              &lt;/plugin&gt;
          &lt;/plugins&gt;
      &lt;/build&gt;
  
      &lt;repositories&gt;
          &lt;repository&gt;
              &lt;id&gt;spring-releases&lt;/id&gt;
              &lt;name&gt;Spring Milestone Repository&lt;/name&gt;
              &lt;url&gt;https://repo.spring.io/libs-release&lt;/url&gt;
          &lt;/repository&gt;
      &lt;/repositories&gt;
  
      &lt;pluginRepositories&gt;
          &lt;pluginRepository&gt;
              &lt;id&gt;spring-releases&lt;/id&gt;
              &lt;name&gt;Spring Milestone Repository&lt;/name&gt;
              &lt;url&gt;https://repo.spring.io/libs-release&lt;/url&gt;
          &lt;/pluginRepository&gt;
      &lt;/pluginRepositories&gt;
  &lt;/project&gt;
  </code></pre>
  
  <p><strong>XML settings inside .m2 folder:</strong></p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;settings&gt;
  &lt;proxies&gt;
      &lt;proxy&gt;
        &lt;id&gt;optional&lt;/id&gt;
        &lt;active&gt;true&lt;/active&gt;
        &lt;protocol&gt;http&lt;/protocol&gt;
        &lt;username&gt;MY_USER&lt;/username&gt;
        &lt;password&gt;MY_PASSWORD&lt;/password&gt;
        &lt;host&gt;MY_HOST&lt;/host&gt;
        &lt;port&gt;3128&lt;/port&gt;
      &lt;/proxy&gt;
  &lt;/proxies&gt;
  &lt;/settings&gt;
  </code></pre>
  
  <p><strong>Output from "mvn -version":</strong></p>
  
  <pre><code>C:\Users\MY_USER&gt;mvn -version
  Apache Maven 3.3.9 (bb52d8502b132ec0a5a3f4c09453c07478323dc5; 2015-11-10T17:41:47+01:00)
  Maven home: C:\Progra~1\apache-maven-3.3.9
  Java version: 1.8.0_77, vendor: Oracle Corporation
  Java home: C:\Progra~1\Java\jdk1.8.0_77\jre
  Default locale: it_IT, platform encoding: Cp1252
  OS name: "windows 8.1", version: "6.3", arch: "amd64", family: "dos"
  </code></pre>
  
  <p><strong>The problem:</strong></p>
  
  <p>So far i have been able to compile, run and create the standalone jar file service, but using in the Command Prompt (each one does perfectly):</p>
  
  <pre><code>mvn spring-boot:run
  mvn clean package
  </code></pre>
  
  <p><strong>MY</strong> problem is that when i do in Eclipse: Select Project > Run as.. Maven Build</p>
  
  <p>Always get this Exception (no matter what i change or what i put or edit or reinstall in the system):</p>
  
  <pre><code>java.lang.Exception: classworlds configuration not specified nor found in the classpath at  org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:406) at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
  </code></pre>
  
  <p><strong>What i have done so far?</strong></p>
  
  <p><strong>First</strong></p>
  
  <p>Among all the things in the setting that i changed and re-installed all from zero (even Java and Maven).</p>
  
  <p>I notice is the source code of this "Launcher" in the plexus which experts would understand but i put the link for sake of the all with the same problem:</p>
  
  <p><a href="https://codehaus-plexus.github.io/plexus-classworlds/xref/org/codehaus/plexus/classworlds/launcher/Launcher.html" rel="nofollow">https://codehaus-plexus.github.io/plexus-classworlds/xref/org/codehaus/plexus/classworlds/launcher/Launcher.html</a></p>
  
  <p>It seen's that im missing a classworlds.conf file at the maven installation directory, but i have no idea what should have inside or where to put it.</p>
  
  <p><strong>Second</strong></p>
  
  <p>I have also seen in GitHub some programmer that have their own classwordls.conf files but i dont understand where do i have to put it, or why this exception appears ONLY in Eclipse and not in the Command Prompt.</p>
  
  <p><strong>Third</strong></p>
  
  <p>Also i notice that some people have changed M2_HOME to M3_HOME (worked for some Mac users i saw around in StackOverflow).</p>
  
  <p><strong>Forth</strong></p>
  
  <p>I saw that others said it was a dependence on the "plexus-classworlds-2.5.2.jar" located in M2_HOME\boot. I didn't understood why, Maven <strong>"should"</strong> handle all dependencies. </p>
  
  <p>Thank you in advance.</p>