Maven 无法执行'；mvn camel:run'；关于Camel示例项目

我对camel还不熟悉，我一直在尝试运行camel中的一个示例，名为camel-example-twitter-websocket，可能是

当我运行

mvn compile

时，它会成功运行

$ mvn compile
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building Camel :: Example :: Twitter WebSocket 2.17-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- maven-enforcer-plugin:1.4:enforce (enforce-maven) @ camel-example-twitter-websocket ---
[INFO]
[INFO] --- maven-bundle-plugin:2.3.7:cleanVersions (versions) @ camel-example-twitter-websocket ---
[INFO]
[INFO] --- maven-remote-resources-plugin:1.5:process (default) @ camel-example-twitter-websocket ---
[INFO]
[INFO] --- maven-resources-plugin:2.7:resources (default-resources) @ camel-example-twitter-websocket ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 4 resources
[INFO] Copying 3 resources
[INFO]
[INFO] --- maven-resources-plugin:2.7:resources (default) @ camel-example-twitter-websocket ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 4 resources
[INFO] Copying 3 resources
[INFO]
[INFO] --- maven-compiler-plugin:3.5.1:compile (default-compile) @ camel-example-twitter-websocket ---
[INFO] Nothing to compile - all classes are up to date
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.504 s
[INFO] Finished at: 2016-03-18T15:27:30-04:00
[INFO] Final Memory: 22M/437M
[INFO] ------------------------------------------------------------------------

但是，当我运行第二步时，mvn camel:run不起作用，我得到以下输出

$ mvn camel:run
[INFO] Scanning for projects...
[WARNING] The POM for org.apache.camel:camel-maven-plugin:jar:2.17-20151107.033312-28 is invalid, transitive dependencies (if any) will not be av         ailable, enable debug logging for more details
[WARNING] Failed to retrieve plugin descriptor for org.apache.camel:camel-maven-plugin:2.17-SNAPSHOT: Plugin org.apache.camel:camel-maven-plugin:         2.17-SNAPSHOT or one of its dependencies could not be resolved: Failed to read artifact descriptor for org.apache.camel:camel-maven-plugin:jar:2.         17-SNAPSHOT
[WARNING] The POM for org.eclipse.m2e:lifecycle-mapping:jar:1.0.0 is missing, no dependency information available
[WARNING] Failed to retrieve plugin descriptor for org.eclipse.m2e:lifecycle-mapping:1.0.0: Plugin org.eclipse.m2e:lifecycle-mapping:1.0.0 or one          of its dependencies could not be resolved: Failure to find org.eclipse.m2e:lifecycle-mapping:jar:1.0.0 in https://repo.maven.apache.org/maven2 w         as cached in the local repository, resolution will not be reattempted until the update interval of central has elapsed or updates are forced
[WARNING] The POM for org.apache.maven.plugins:maven-surefire-plugin:jar:{maven-surefire-plugin-version} is missing, no dependency information av         ailable
[WARNING] Failed to retrieve plugin descriptor for org.apache.maven.plugins:maven-surefire-plugin:{maven-surefire-plugin-version}: Plugin org.apa         che.maven.plugins:maven-surefire-plugin:{maven-surefire-plugin-version} or one of its dependencies could not be resolved: Failure to find org.apa         che.maven.plugins:maven-surefire-plugin:jar:{maven-surefire-plugin-version} in https://repo.maven.apache.org/maven2 was cached in the local repos         itory, resolution will not be reattempted until the update interval of central has elapsed or updates are forced
Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-metadata.xml
Downloading: https://repository.apache.org/content/repositories/snapshots/org/apache/maven/plugins/maven-metadata.xml
Downloading: https://repo.maven.apache.org/maven2/org/codehaus/mojo/maven-metadata.xml
Downloading: https://repository.apache.org/content/repositories/snapshots/org/codehaus/mojo/maven-metadata.xml
Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-metadata.xml (13 KB at 36.9 KB/sec)
Downloaded: https://repo.maven.apache.org/maven2/org/codehaus/mojo/maven-metadata.xml (20 KB at 57.4 KB/sec)
Downloaded: https://repository.apache.org/content/repositories/snapshots/org/apache/maven/plugins/maven-metadata.xml (9 KB at 9.7 KB/sec)
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 2.140 s
[INFO] Finished at: 2016-03-18T15:28:29-04:00
[INFO] Final Memory: 27M/327M
[INFO] ------------------------------------------------------------------------
[ERROR] No plugin found for prefix 'camel' in the current project and in the plugin groups [org.apache.maven.plugins, org.codehaus.mojo] availabl         e from the repositories [local (C:\Users\myNameHere\.m2\repository), apache.snapshots (https://repository.apache.org/content/repositories/snapshots/),          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

---

看起来这更像是一个专家问题，而不是骆驼问题。我放入了默认的.m2/settings.xml文件（在我为我的公司Nexus存储库配置镜像之前。我认为这可能会把事情搞砸，所以我把它全部取出来）。出于绝望，我甚至尝试从这里添加插件库，但没有成功。

我已经测试了自己，而使用插件2.16也无法解决问题

但在自述中，我发现：

We have described this in more details at the Camel twitter documentation:
  http://camel.apache.org/twitter

You will need to compile this example first:
  mvn compile

To run the example type
  mvn exec:java

Then open a browser to see live twitter updates in the web page
  http://localhost:9090

---

为我工作，我希望它也能为你工作。我将调查这个插件的问题，它似乎没有导出前缀后者。

阅读自述文件如何运行示例

一些示例使用

mvn camel:run

运行，其他示例使用

mvn exec:java

和其他什么运行

您可以从源代码中的主分支运行。相反，您应该下载一个Camel版本，比如最新的2.16.2并使用它。它在examples目录中提供示例：

如果在源代码中从主分支运行。首先需要重建Camel，请参见构建：