struts和spring的上下文结合的地方（上下文结合）

struts再一次包装了spring的webapplicationcontext（webapplication本源都是从servletcontext获取）

servletcontext这里有配置文件的参数等信息，还有bean之间的关联关系，并且把这种关联关系封装成map

核心结合jar包

struts2-spring-plugin-2.1.6.jar

struts-plugin.xml:

<bean type="com.opensymphony.xwork2.ObjectFactory" name="spring" class="org.apache.struts2.spring.StrutsSpringObjectFactory" />

 <package name="spring-default">

        <interceptors>

            <interceptor name="autowiring" class="com.opensymphony.xwork2.spring.interceptor.ActionAutowiringInterceptor"/>

            <interceptor name="sessionAutowiring" class="org.apache.struts2.spring.interceptor.SessionContextAutowiringInterceptor"/>

        </interceptors>

    </package>   

这个拦截器包装了action的context和webapplicationcontext

(一)

struts中注入webaoolicationcontext

StrutsSpringObjectFactory  实现了implements ApplicationContextAware

@Inject静态注入

从servletcontext获取webapplicationcontext

@Inject

    public StrutsSpringObjectFactory(

            @Inject(value=StrutsConstants.STRUTS_OBJECTFACTORY_SPRING_AUTOWIRE,required=false) String autoWire,

            @Inject(value=StrutsConstants.STRUTS_OBJECTFACTORY_SPRING_AUTOWIRE_ALWAYS_RESPECT,required=false) String alwaysAutoWire,

            @Inject(value=StrutsConstants.STRUTS_OBJECTFACTORY_SPRING_USE_CLASS_CACHE,required=false) String useClassCacheStr,

            @Inject ServletContext servletContext) {

        super();

        boolean useClassCache = "true".equals(useClassCacheStr);

        LOG.info("Initializing Struts-Spring integration...");

        ApplicationContext appContext = (ApplicationContext) servletContext.getAttribute(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE);

        if (appContext == null) {

            // uh oh! looks like the lifecycle listener wasn't installed. Let's inform the user

            String message = "********** FATAL ERROR STARTING UP STRUTS-SPRING INTEGRATION **********\n" +

                    "Looks like the Spring listener was not configured for your web app! \n" +

                    "Nothing will work until WebApplicationContextUtils returns a valid ApplicationContext.\n" +

                    "You might need to add the following to web.xml: \n" +

                    "    <listener>\n" +

                    "        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>\n" +

                    "    </listener>";

            LOG.fatal(message);

            return;

        }

        this.setApplicationContext(appContext);

        int type = AutowireCapableBeanFactory.AUTOWIRE_BY_NAME;   // default

        if ("name".equals(autoWire)) {

            type = AutowireCapableBeanFactory.AUTOWIRE_BY_NAME;

        } else if ("type".equals(autoWire)) {

            type = AutowireCapableBeanFactory.AUTOWIRE_BY_TYPE;

        } else if ("auto".equals(autoWire)) {

            type = AutowireCapableBeanFactory.AUTOWIRE_AUTODETECT;

        } else if ("constructor".equals(autoWire)) {

            type = AutowireCapableBeanFactory.AUTOWIRE_CONSTRUCTOR;

        }

        this.setAutowireStrategy(type);

        this.setUseClassCache(useClassCache);

        this.setAlwaysRespectAutowireStrategy("true".equalsIgnoreCase(alwaysAutoWire));

        LOG.info("... initialized Struts-Spring integration successfully");

    }

(二)

拦截器中（使用webapplicationcontext）：

 利用spring的context封装成struts自己的context

ActionAutowiringInterceptor （StrutsSpringObjectFactory中@Inject静态注入了webapplicationcontext）

  public String intercept(ActionInvocation invocation)

    throws Exception

  {

    if (!this.initialized)

    {

      ApplicationContext applicationContext = (ApplicationContext)ActionContext.getContext().getApplication().get(WebApplicationContext.ROOT_WEB_APPLICATION_CONTEXT_ATTRIBUTE);

      if (applicationContext == null)

      {

        if (LOG.isWarnEnabled()) {

          LOG.warn("ApplicationContext could not be found.  Action classes will not be autowired.", new String[0]);

        }

      }

      else

      {

        setApplicationContext(applicationContext);

        this.factory = new SpringObjectFactory();

        this.factory.setApplicationContext(getApplicationContext());

        if (this.autowireStrategy != null) {

          this.factory.setAutowireStrategy(this.autowireStrategy.intValue());

        }

      }

      this.initialized = true;

    }

    if (this.factory != null)

    {

      Object bean = invocation.getAction();

      this.factory.autoWireBean(bean);

      ActionContext.getContext().put("com.opensymphony.xwork2.spring.interceptor.ActionAutowiringInterceptor.applicationContext", this.context);

    }

    return invocation.invoke();

  }