java - GWT 2.6 控制台警告

Question

这些警告是什么意思？

[WARN] Server class 'org.eclipse.jetty.servlet.listener.ELContextCleaner' could not be found in the web app, but was found on the system classpath
   [WARN] Adding classpath entry 'file:/Applications/gwt/gwt-2.6.0/gwt-dev.jar' to the web app classpath for this session
   For additional info see: file:/Applications/gwt/gwt-2.6.0/doc/helpInfo/webAppClassPath.html
[WARN] Server class 'org.slf4j.Logger' could not be found in the web app, but was found on the system classpath
   [WARN] Adding classpath entry 'file:/Users/mg/Documents/Grails/GGTS3.5M1/buddyis/lib/gwt/slf4j-api-1.7.5.jar' to the web app classpath for this session
   For additional info see: file:/Applications/gwt/gwt-2.6.0/doc/helpInfo/webAppClassPath.html
[WARN] Server class 'org.slf4j.impl.StaticLoggerBinder' could not be found in the web app, but was found on the system classpath
   [WARN] Adding classpath entry 'file:/Users/mg/Documents/Grails/GGTS3.5M1/buddyis/lib/gwt/mobile/slf4j-log4j12-1.7.5.jar' to the web app classpath for this session
   For additional info see: file:/Applications/gwt/gwt-2.6.0/doc/helpInfo/webAppClassPath.html
[WARN] Server class 'org.apache.log4j.Level' could not be found in the web app, but was found on the system classpath
   [WARN] Adding classpath entry 'file:/Users/mg/Documents/Grails/GGTS3.5M1/buddyis/lib/gwt/mobile/log4j-1.2.17.jar' to the web app classpath for this session
   For additional info see: file:/Applications/gwt/gwt-2.6.0/doc/helpInfo/webAppClassPath.html
log4j:WARN No appenders could be found for logger (org.eclipse.jetty.util.log).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
log4j:WARN No appenders could be found for logger (org.apache.jasper.compiler.JspRuntimeContext).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.

Answer 1

第一组警告是因为当您运行开发模式时，它会启动一个 servlet 容器 (Jetty)，该容器默认配置为在未找到类发生时使用项目类路径中的任何库。这些警告有助于了解您必须将哪些库添加到生产中的 .war 工件中。

第二组警告是因为您还没有为您的项目配置 log4j。