一、前言

关于springframework的spring-web包中org.springframework.web.SpringServletContainerInitializer启动容器类,实现了javax.servlet.ServletContainerInitializer容器接口，从而实现不通过web.xml 启动JavaEE项目，详情参见源码说明。

二、源码说明

package org.springframework.web;@b@@b@import java.lang.reflect.Modifier;@b@import java.util.LinkedList;@b@import java.util.List;@b@import java.util.Set;@b@import javax.servlet.ServletContainerInitializer;@b@import javax.servlet.ServletContext;@b@import javax.servlet.ServletException;@b@import javax.servlet.annotation.HandlesTypes;@b@import org.springframework.core.annotation.AnnotationAwareOrderComparator;@b@@b@@HandlesTypes({WebApplicationInitializer.class})@b@public class SpringServletContainerInitializer@b@  implements ServletContainerInitializer@b@{@b@  public void onStartup(Set<Class<?>> webAppInitializerClasses, ServletContext servletContext)@b@    throws ServletException@b@  {@b@    List initializers = new LinkedList();@b@@b@    if (webAppInitializerClasses != null)@b@      for (Class waiClass : webAppInitializerClasses)@b@      {@b@        if ((!(waiClass.isInterface())) && (!(Modifier.isAbstract(waiClass.getModifiers()))) && @b@          (WebApplicationInitializer.class@b@          .isAssignableFrom(waiClass)))@b@          try@b@          {@b@            initializers.add((WebApplicationInitializer)waiClass.newInstance());@b@          }@b@          catch (Throwable ex) {@b@            throw new ServletException("Failed to instantiate WebApplicationInitializer class", ex);@b@          }@b@@b@      }@b@@b@@b@    if (initializers.isEmpty()) {@b@      servletContext.log("No Spring WebApplicationInitializer types detected on classpath");@b@      return;@b@    }@b@@b@    servletContext.log(initializers.size() + " Spring WebApplicationInitializers detected on classpath");@b@    AnnotationAwareOrderComparator.sort(initializers);@b@    for (WebApplicationInitializer initializer : initializers)@b@      initializer.onStartup(servletContext);@b@  }@b@}