我可以发现了一个SpringMVC框架的Bug，描述如下：

最新推荐文章于 2023-10-18 15:36:11 发布

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最新推荐文章于 2023-10-18 15:36:11 发布

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原文链接：https://my.oschina.net/u/614221/blog/919664

本文探讨了一个 Spring MVC 应用中出现的两个 WebApplicationContext 上下文同时被初始化的问题，并提供了详细的日志记录及代码片段以帮助理解这一不合理现象。

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（1）

配置文件web.xml其中的片段：

<servlet>
   <servlet-name>OOXXappServlet</servlet-name>
   <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
   <init-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>/WEB-INF/spring/OOXXappServlet/servlet-context.xml</param-value>
   </init-param>
</servlet>

（2）

使用如下代码，获取ServletContext：

WebApplicationContext wac = ContextLoader.getCurrentWebApplicationContext();
ServletContext sc = wac.getServletContext();
if (sc != null) {
   out.println(
         "\n\tWAC getServletContextName\t" + sc.getServletContextName() +
         "\n\tWAC getClassLoader\t" + sc.getClassLoader() +
         "\n\tWAC getClass\t" + sc.getClass() +
         "\n\tWAC getAttributeNames\t" + sc.getAttributeNames().toString() +
         "\n\tWAC getContextPath\t" + sc.getContextPath() +
         "\n\tWAC getInitParameterNames\t" + sc.getInitParameterNames().toString() +
         "\n\tWAC getServerInfo\t" + sc.getServerInfo() +
         "\n\tWAC getSessionCookieConfig\t" + sc.getSessionCookieConfig()
   );

   Enumeration<String> es = sc.getAttributeNames();
   while (es.hasMoreElements()){
      String attr = es.nextElement().toString();
      out.println(
                  attr +
                  "\t:\t" +
                  sc.getAttribute(attr)
      );
   }
}

（3）上面代码的执行Log：

WAC getServletContextName /
WAC getClassLoader WebAppClassLoader=105146840@64469d8
WAC getClass class org.eclipse.jetty.webapp.WebAppContext$Context
WAC getAttributeNames java.util.Collections$3@5c9d540c
WAC getContextPath
WAC getInitParameterNames java.util.Collections$3@126898e2
WAC getServerInfo jetty/9.4.1.v20170120
WAC getSessionCookieConfig org.eclipse.jetty.server.session.SessionHandler$CookieConfig@90ed286

   javax.servlet.context.tempdir : E:\JavaTryCatch\spring-mvc-showcase\target\tmp
   org.eclipse.jetty.server.webapp.ContainerIncludeJarPattern : .*/javax.servlet-[^/]*\.jar$|.*/servlet-api-[^/]*\.jar$|.*javax.servlet.jsp.jstl-[^/]*\.jar|.*taglibs-standard-impl-.*\.jar
   org.eclipse.jetty.util.DecoratedObjectFactory : org.eclipse.jetty.util.DecoratedObjectFactory[decorators=3]
   org.springframework.web.servlet.FrameworkServlet.CONTEXT.OOXXappServlet : WebApplicationContext for namespace 'OOXXappServlet-servlet': startup date [Mon Jun 12 18:22:41 CST 2017]; parent: Root WebApplicationContext
   org.eclipse.jetty.websocket.server.WebSocketUpgradeFilter.SCI : WebSocketUpgradeFilter[configuration=org.eclipse.jetty.websocket.server.NativeWebSocketConfiguration@7a191211]
   org.eclipse.jetty.resource.postOverlay : file:///E:/JavaTryCatch/spring-mvc-showcase/src/main/webapp/
   org.eclipse.jetty.lifecyleCallbackCollection : org.eclipse.jetty.plus.annotation.LifeCycleCallbackCollection@4c92146a
   resourceCache : ResourceCache[null,org.eclipse.jetty.servlet.DefaultServlet@1aeb2a92]@1703825835
   org.eclipse.jetty.websocket.server.NativeWebSocketConfiguration : org.eclipse.jetty.websocket.server.NativeWebSocketConfiguration@7a191211
   org.apache.tomcat.InstanceManager : org.apache.tomcat.SimpleInstanceManager@57b55e91
   org.eclipse.jetty.tmpdirConfigured : true
   org.eclipse.jetty.server.Executor : qtp2189588{STARTED,8<=13<=200,i=7,q=0}
   org.eclipse.jetty.injectionCollection : org.eclipse.jetty.plus.annotation.InjectionCollection@bd82149
   org.eclipse.jetty.runAsCollection : org.eclipse.jetty.plus.annotation.RunAsCollection@4824251a
   org.apache.jasper.compiler.ELInterpreter : org.apache.jasper.compiler.ELInterpreterFactory$DefaultELInterpreter@5fb026bc
   org.eclipse.jetty.containerInitializerStarter : org.eclipse.jetty.annotations.ServletContainerInitializersStarter@220caa0d
   org.apache.jasper.compiler.TldCache : org.apache.jasper.compiler.TldCache@6814156c
   org.springframework.web.servlet.FrameworkServlet.CONTEXT.dispatcherServlet : WebApplicationContext for namespace 'dispatcherServlet-servlet': startup date [Mon Jun 12 18:22:38 CST 2017]; parent: Root WebApplicationContext
   org.springframework.web.context.WebApplicationContext.ROOT : Root WebApplicationContext: startup date [Mon Jun 12 18:22:38 CST 2017]; root of context hierarchy
   org.springframework.web.context.support.ServletContextScope : org.springframework.web.context.support.ServletContextScope@171f181
   org.eclipse.jetty.websocket.server.WebSocketUpgradeFilter : WebSocketUpgradeFilter[configuration=org.eclipse.jetty.websocket.server.NativeWebSocketConfiguration@7a191211]
   javax.websocket.server.ServerContainer : org.eclipse.jetty.websocket.jsr356.server.ServerContainer@5faaa2d5
   org.apache.jasper.runtime.JspApplicationContextImpl : org.apache.jasper.runtime.JspApplicationContextImpl@18b127ef

（4）问题描述

可以在上面的记录中，attribute里有2个“子上下文”：

org.springframework.web.servlet.FrameworkServlet.CONTEXT.OOXXappServlet 和 org.springframework.web.servlet.FrameworkServlet.CONTEXT.dispatcherServlet

其value分别是：
WebApplicationContext for namespace 'dispatcherServlet-servlet': startup date [Mon Jun 12 18:22:38 CST 2017]; parent: Root WebApplicationContext
和 WebApplicationContext for namespace 'OOXXappServlet-servlet': startup date [Mon Jun 12 18:22:41 CST 2017]; parent: Root WebApplicationContext

也就是说，同时初始化了2个MVC上下文，这是不合理的啊；所以，应该算是一个Bug吧！

转载于:https://my.oschina.net/u/614221/blog/919664