httprequest在aspect中未自动连接

Question

我正在使用以下方面拦截对某个类的getDescription方法的调用。

@Aspect
public class InternationalizationAspect {

    private static final String LANGUAGE_CODE_ENGLISH = "en";
    private static Logger log = LoggerFactory.getLogger(InternationalizationAspect.class);

    @Autowired
    InternationalizationService internationalizationService;

    @Autowired
    private HttpServletRequest httpServletRequest;

    @Around("execution(* com.***.***.***.***.getDescription(..))")
    public Object getInternationalizedTitleDescription(ProceedingJoinPoint joinPoint) throws Throwable {
        log.info("title getdescription intercepted");
        if (httpServletRequest == null) {
            log.info("http servlet request was not autowired correctly");
            return joinPoint.proceed();
        } else {
            Locale locale = httpServletRequest.getLocale();
            log.info("locale is = " + locale);
            if (locale.getLanguage().equals(new Locale(LANGUAGE_CODE_ENGLISH).getLanguage())) {
                return joinPoint.proceed();
            } else {
                log.info("getting internationalized description");
                Title t = (Title) joinPoint.getTarget();
                return internationalizationService.getTitleDescriptionFromTitleAndLocale(t, locale);
            }
        }
    }
}

对于上述方面，我得到以下输出：

title getdescription intercepted
http servlet request was not autowired correctly
title getdescription intercepted
http servlet request was not autowired correctly
title getdescription intercepted
http servlet request was not autowired correctly
title getdescription intercepted
http servlet request was not autowired correctly

在我的应用程序上下文中。xml，我有：

<bean id="internationalizationAspect" class="com.***.***.***.InternationalizationAspect" />
<context:component-scan base-package="com.***">
        <context:exclude-filter expression=".*_Roo_.*" type="regex"/>
        <context:exclude-filter expression="org.springframework.stereotype.Controller" type="annotation"/>
</context:component-scan>

在我的方面，为什么spring没有自动连接httpservletrequest。根据这个答案：自动连线HttpServletRequestbean的Spring AOP和aspect线程安全

它应该工作。

编辑

我的web.xml如下：

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://java.sun.com/xml/ns/javaee"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
        xsi:schemaLocation="http://java.sun.com/xml/ns/javaee
                            http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">

    <display-name>Spring Web Application example</display-name>

    <!-- Configurations for the root application context (parent context) -->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>
            /META-INF/spring/applicationContext.xml
        </param-value>
    </context-param>

    <!-- Configurations for the DispatcherServlet application context (child context) -->
    <servlet>
        <servlet-name>spring-mvc</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <init-param>
            <param-name>contextConfigLocation</param-name>
            <param-value>
                /WEB-INF/spring/mvc/spring-mvc-servlet.xml
            </param-value>
        </init-param>
    </servlet>
    <servlet-mapping>
        <servlet-name>spring-mvc</servlet-name>
        <url-pattern>/admin/*</url-pattern>
    </servlet-mapping>

</web-app>

我正在applicationcontext中定义我的方面bean。不在spring mvc servlet中的xml。xml

Answer 1

您需要启用注释配置，可以使用

<context:annotation-config />

或

<context:component-scan ... />

根据以上内容，并假设您在bean上操作，Autowired字段永远不能为null。如果Spring不能注入它，它将抛出异常。