作爲一個初學者，我們在學習java的過程中
難免會遇到一些這樣的問題：
使用maven創建了項目之後，選擇jetty：run
命令卻無法執行，提示如下的錯誤：
[INFO] Scanning for projects...
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-install-plugin/2.4/maven-install-plugin-2.4.pom
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-install-plugin/2.4/maven-install-plugin-2.4.pom (7 KB at 1.7 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-deploy-plugin/2.7/maven-deploy-plugin-2.7.pom
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-deploy-plugin/2.7/maven-deploy-plugin-2.7.pom (6 KB at 6.3 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-site-plugin/3.3/maven-site-plugin-3.3.pom
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-site-plugin/3.3/maven-site-plugin-3.3.pom (21 KB at 24.5 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-antrun-plugin/1.3/maven-antrun-plugin-1.3.pom
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-antrun-plugin/1.3/maven-antrun-plugin-1.3.pom (5 KB at 6.3 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-plugins/12/maven-plugins-12.pom
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-plugins/12/maven-plugins-12.pom (12 KB at 19.5 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-antrun-plugin/1.3/maven-antrun-plugin-1.3.jar
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-antrun-plugin/1.3/maven-antrun-plugin-1.3.jar (24 KB at 13.1 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-assembly-plugin/2.2-beta-5/maven-assembly-plugin-2.2-beta-5.pom
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-assembly-plugin/2.2-beta-5/maven-assembly-plugin-2.2-beta-5.pom (15 KB at 12.0 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-plugins/16/maven-plugins-16.pom
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-plugins/16/maven-plugins-16.pom (13 KB at 11.8 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/maven-parent/15/maven-parent-15.pom
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/maven-parent/15/maven-parent-15.pom (24 KB at 31.4 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/apache/6/apache-6.pom
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/apache/6/apache-6.pom (13 KB at 18.7 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-assembly-plugin/2.2-beta-5/maven-assembly-plugin-2.2-beta-5.jar
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-assembly-plugin/2.2-beta-5/maven-assembly-plugin-2.2-beta-5.jar (204 KB at 86.8 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-dependency-plugin/2.8/maven-dependency-plugin-2.8.pom
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-dependency-plugin/2.8/maven-dependency-plugin-2.8.pom (12 KB at 17.6 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-dependency-plugin/2.8/maven-dependency-plugin-2.8.jar
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-dependency-plugin/2.8/maven-dependency-plugin-2.8.jar (150 KB at 93.2 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-release-plugin/2.3.2/maven-release-plugin-2.3.2.pom
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-release-plugin/2.3.2/maven-release-plugin-2.3.2.pom (10 KB at 15.5 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/release/maven-release/2.3.2/maven-release-2.3.2.pom
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/release/maven-release/2.3.2/maven-release-2.3.2.pom (9 KB at 14.5 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-release-plugin/2.3.2/maven-release-plugin-2.3.2.jar
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-release-plugin/2.3.2/maven-release-plugin-2.3.2.jar (44 KB at 49.5 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-metadata.xml
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/codehaus/mojo/maven-metadata.xml
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-metadata.xml (13 KB at 20.8 KB/sec)
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/codehaus/mojo/maven-metadata.xml (20 KB at 12.1 KB/sec)
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 22.194 s
[INFO] Finished at: 2017-07-12T16:14:18+08:00
[INFO] Final Memory: 11M/176M
[INFO] ------------------------------------------------------------------------
[ERROR] No plugin found for prefix 'jetty' in the current project and in the plugin groups [org.apache.maven.plugins, org.codehaus.mojo] available from the repositories [local (C:\Users\Administrator\.m2\repository), central (https://repo.maven.apache.org/maven2)] -> [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/NoPluginFoundForPrefixException
其中所報的錯誤就是：
No plugin found for prefix 'jetty' in the current project and in the plugin groups那麼這個說明了什麼呢？
說明我們在插件集裏面沒有jetty這個插件，解決辦法如下：
<pluginGroups>
<pluginGroup>org.mortbay.jetty</pluginGroup>
</pluginGroups>
