Maven使用出错

在运行这个例子的时候出错了：http://wiki.eclipse.org/Jetty/Tutorial/Jetty_and_Maven_HelloWorld

出错信息如下：
C:\jetty\JettyMavenHelloWorld>mvn clean compile exec:java
[INFO] Scanning for projects...
Downloading: http://repo1.maven.org/maven2/org/codehaus/mojo/exec-maven-plugin/1.1/exec-maven-plugin-1.1.pom
[WARNING] Unable to get resource 'org.codehaus.mojo:exec-maven-plugin:pom:1.1' from repository central (http://repo1.maven.org/maven2): Error transferring file: Connection timed out: connect
Downloading: http://repo1.maven.org/maven2/org/codehaus/mojo/exec-maven-plugin/1.1/exec-maven-plugin-1.1.pom
[WARNING] Unable to get resource 'org.codehaus.mojo:exec-maven-plugin:pom:1.1' from repository central (http://repo1.maven.org/maven2): Error transferring file: Connection timed out: connect
[INFO] ------------------------------------------------------------------------
[ERROR] BUILD ERROR
[INFO] ------------------------------------------------------------------------
[INFO] Failed to resolve artifact.

GroupId: org.codehaus.mojo
ArtifactId: exec-maven-plugin
Version: 1.1

Reason: Unable to download the artifact from any repository

  org.codehaus.mojo:exec-maven-plugin:pom:1.1

from the specified remote repositories:
  central (http://repo1.maven.org/maven2)



[INFO] ------------------------------------------------------------------------
[INFO] For more information, run Maven with the -e switch
[INFO] ------------------------------------------------------------------------
[INFO] Total time: 42 seconds
[INFO] Finished at: Fri Sep 17 16:07:52 CST 2010
[INFO] Final Memory: 1M/3M
[INFO] ------------------------------------------------------------------------

其实我在家里是可以运行的，所以唯一的问题就是http proxy的问题。我的IE里是有设置proxy的，而且在maven的settings.xml文件里也设置了，但还是无法下载。搞不懂，看来要用Maven的话，只能在家里弄了。
我还尝试在本机建一个Maven的repository，但是运行到后来也是不能下载到那些东西而失败。
有空再继续关注的吧。