Question

在我的网络应用程序中使用Async DeferredResult Long Polling时遇到问题。

具体来说，我收到错误＆＃34; java.lang.IllegalStateException：必须在servlet和异步请求处理中涉及的所有过滤器上启用异步支持。这是使用Servlet API在Java代码中完成的，或者通过添加＆＃34; true＆＃34;在web.xml中进行servlet和过滤声明。＆＃34;

当我使用Ajax调用调用Controller（@Controller）的一个方法时会生成此错误。

我的应用程序使用以下方式设置：

Spring MVC 3.2
Tomcat 7.0.57
Servlet 3.0.1

我已经遵循了有关web.xml的所有相关说明，并使用标记

完成了所有servlet和过滤器

<async-supported>true</async-supported>

您可以在下面找到所有web.xml

<?xml version="1.0" encoding="UTF-8"?>

http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" 版本=＆＃34; 3.0＆＃34;＆GT;

<!-- The definition of the Root Spring Container shared by all Servlets and Filters -->
<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>
        classpath:net/bull/javamelody/monitoring-spring.xml
        /WEB-INF/spring/root-context.xml
        /WEB-INF/spring/menu-structure.xml
    </param-value>
</context-param>


<!-- Java melody filter mapping and listener -->
<filter>
    <filter-name>monitoring</filter-name>
    <filter-class>net.bull.javamelody.MonitoringFilter</filter-class>
    <async-supported>true</async-supported>
</filter>
<filter-mapping>
    <filter-name>monitoring</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>
<listener>
    <listener-class>net.bull.javamelody.SessionListener</listener-class>
</listener>


<!-- Creates the Spring Container shared by all Servlets and Filters -->
<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

<!-- Processes application requests -->
<servlet>
    <servlet-name>appServlet</servlet-name>
    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
    <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>/WEB-INF/spring/appServlet/servlet-context.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
    <async-supported>true</async-supported>
</servlet>

<servlet-mapping>
    <servlet-name>appServlet</servlet-name>
    <url-pattern>/</url-pattern>
</servlet-mapping>

<!-- Dandelion-Datatables servlet definition -->
<servlet>
    <servlet-name>datatablesController</servlet-name>
    <servlet-class>com.github.dandelion.datatables.extras.servlet2.servlet.DatatablesServlet</servlet-class>
    <async-supported>true</async-supported>
</servlet>

<!-- Dandelion-Datatables servlet mapping -->
<servlet-mapping>
    <servlet-name>datatablesController</servlet-name>
    <url-pattern>/datatablesController/*</url-pattern>
</servlet-mapping>

有什么建议吗？

提前谢谢。

Answer 1

我发现了导致这种行为的原因。

问题主要在于 datatablesController servlet，它被引用到版本0.9.2。具体来说，在我的pom.xml中有：

<dependency>
    <groupId>com.github.dandelion</groupId>
    <artifactId>datatables-jsp</artifactId>
    <version>0.9.2</version>
</dependency>
<dependency>
    <groupId>com.github.dandelion</groupId>
    <artifactId>datatables-servlet2</artifactId>
    <version>0.9.2</version>
</dependency>

因此，为了解决这个问题，我将这些依赖项更改为：

<dependency>
    <groupId>com.github.dandelion</groupId>
    <artifactId>datatables-jsp</artifactId>
    <version>0.10.1</version>
</dependency>

我将web.xml中的datatablesController servlet更改为：

 <!-- Dandelion filter definition and mapping -->
<filter>
    <filter-name>dandelionFilter</filter-name>
    <filter-class>com.github.dandelion.core.web.DandelionFilter</filter-class>
    <async-supported>true</async-supported>
</filter>
<filter-mapping>
    <filter-name>dandelionFilter</filter-name>
    <url-pattern>/</url-pattern>
</filter-mapping>


<!-- Dandelion servlet definition and mapping -->
<servlet>
    <servlet-name>dandelionServlet</servlet-name>
    <servlet-class>com.github.dandelion.core.web.DandelionServlet</servlet-class>
    <async-supported>true</async-supported>
</servlet>
<servlet-mapping>
    <servlet-name>dandelionServlet</servlet-name>
    <url-pattern>/dandelion-assets/</url-pattern>
</servlet-mapping>

一切都按预期工作。

Answer 2

基本上每个<servlet>和<filter>代码都应包含：

 <async-supported>true</async-supported>

它对我有用。请检查以下代码： -

<servlet>
        <servlet-name>mvc-dispatcher</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>

        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>WEB-INF/mvc-dispatcher.xml</param-value>
        </init-param>

        <load-on-startup>1</load-on-startup>
        <async-supported>true</async-supported>
    </servlet>
    <servlet-mapping>
        <servlet-name>mvc-dispatcher</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>


<!-- Spring Security -->
    <filter>
        <filter-name>springSecurityFilterChain</filter-name>
        <filter-class>org.springframework.web.filter.DelegatingFilterProxy</filter-class>
        <async-supported>true</async-supported>
    </filter>

    <filter-mapping>
        <filter-name>springSecurityFilterChain</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

Async DeferredResult长轮询IllegalStateException使用Servlet 3.0 Tomcat 7时出错

2 个答案: