1、我按着向导创建了一个新的项目，可是创建完项目里出现错误，错误说明是


 Description Resource Path Location Type
ArtifactDescriptorException: Failed to read artifact descriptor for javax.servlet:servlet-api🏺2.5: ArtifactResolutionException: Failure to transfer javax.servlet:servlet-api:pom:2.5 from http://nexus.openkoala.org/content/repositories/public-releases/ was cached in the local repository, resolution will not be reattempted until the update interval of koala-releases has elapsed or updates are forced. Original error: Could not transfer artifact javax.servlet:servlet-api:pom:2.5 from/to koala-releases (http://nexus.openkoala.org/content/repositories/public-releases/): null to http://nexus.openkoala.org/content/repositories/public-releases/javax/servlet/servlet-api/2.5/servlet-api-2.5.pom pom.xml


Description Resource Path Location Type
ArtifactDescriptorException: Failed to read artifact descriptor for javax.servlet.jsp:jsp-api🏺2.1: ArtifactResolutionException: Failure to transfer javax.servlet.jsp:jsp-api:pom:2.1 from http://nexus.openkoala.org/content/repositories/public-releases/ was cached in the local repository, resolution will not be reattempted until the update interval of koala-releases has elapsed or updates are forced. Original error: Could not transfer artifact javax.servlet.jsp:jsp-api:pom:2.1 from/to koala-releases (http://nexus.openkoala.org/content/repositories/public-releases/): null to http://nexus.openkoala.org/content/repositories/public-releases/javax/servlet/jsp/jsp-api/2.1/jsp-api-2.1.pom pom.xml 


Description Resource Path Location Type
ArtifactDescriptorException: Failed to read artifact descriptor for jstl:jstl🏺1.1.2: ArtifactResolutionException: Failure to transfer jstl:jstl:pom:1.1.2 from http://nexus.openkoala.org/content/repositories/public-releases/ was cached in the local repository, resolution will not be reattempted until the update interval of koala-releases has elapsed or updates are forced. Original error: Could not transfer artifact jstl:jstl:pom:1.1.2 from/to koala-releases (http://nexus.openkoala.org/content/repositories/public-releases/): null to http://nexus.openkoala.org/content/repositories/public-releases/jstl/jstl/1.1.2/jstl-1.1.2.pom pom.xml 


Description Resource Path Location Type
Error resolving version for plugin 'org.mortbay.jetty:jetty-maven-plugin' from the repositories [local (E:\eclipseKO\repository), central (http://repo1.maven.org/maven2)]: Plugin not found in any plugin repository pom.xml /demo-web line 1 Maven pom Loading Problem


Description Resource Path Location Type
Plugin execution not covered by lifecycle configuration: org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile (execution: default-compile, phase: compile) pom.xml /demo-conf line 13 Maven Project Build Lifecycle Mapping Problem


2、第二个问题是：我启动run as，控制台出现错误：[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 (E:\eclipseKO\repository), central (http://repo1.maven.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



请哪位大神帮帮我，我就纠结了好几天了，痛苦呀！！！