S2S3H4框架深度集成搭建(2) Spring的深度集成

 

上一篇，寫了struts2中的關鍵問題，至於詳細的集成過程，我就不細表了，除了我描述的關鍵問題之外，其餘的都雷同。下面說說Spring的集成，網上搜的文章中大多介紹spring和struts2的集成，都是同一套路，將spring的配置往src根目錄一扔，而後在web.xml中配個監聽器，而後在struts2的配置中增長struts.objectFactory的描述。就完了，雖然好用，可是都是照葫蘆畫瓢，不知因此然。其實struts既然有這個個描述，那就意味着，struts2中全部實例的獲取，都要經過這個定義的ObjectFactory來獲取，工廠裏用什麼方式獲取對象就和什麼集成，因此，和spring的集成關鍵不在web.xml的配置上，甚至web.xml上的監聽能夠徹底不要。下面咱們就來實際的作一下：編寫XKStrutsSpringObjectFactory繼承SpringObjectFactory， 代碼以下：

public class XKStrutsSpringObjectFactory extends SpringObjectFactory
{
    /**
     *
     */
    private static final long serialVersionUID = 1L;
    private static final Logger LOG = LoggerFactory.getLogger(XKStrutsSpringObjectFactory.class);


    @SuppressWarnings("deprecation")
    @Inject
    public XKStrutsSpringObjectFactory(@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,
            @Inject(StrutsConstants.STRUTS_DEVMODE) String devMode, @Inject Container container)
    {

        super();
        boolean useClassCache = "true".equals(useClassCacheStr);
        if (LOG.isInfoEnabled())
        {
            LOG.info("Initializing Struts-Spring integration...");
        }

  // 關鍵代碼
        Object rootWebApplicationContext = Initialization.getInstance().getApplicationContext();

        if (rootWebApplicationContext instanceof RuntimeException)
        {
            RuntimeException runtimeException = (RuntimeException) rootWebApplicationContext;
            LOG.fatal(runtimeException.getMessage());
            return;
        }

        ApplicationContext appContext = (ApplicationContext) rootWebApplicationContext;
        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;
        }

        String watchList = container.getInstance(String.class, "struts.class.reloading.watchList");
        String acceptClasses = container.getInstance(String.class, "struts.class.reloading.acceptClasses");
        String reloadConfig = container.getInstance(String.class, "struts.class.reloading.reloadConfig");

        if ("true".equals(devMode) && StringUtils.isNotBlank(watchList) && appContext instanceof Cla***eloadingXMLWebApplicationContext)
        {
            // prevent class caching
            useClassCache = false;

            Cla***eloadingXMLWebApplicationContext reloadingContext = (Cla***eloadingXMLWebApplicationContext) appContext;
            reloadingContext.setupReloading(watchList.split(","), acceptClasses, servletContext, "true".equals(reloadConfig));
            if (LOG.isInfoEnabled())
            {
                LOG.info("Class reloading is enabled. Make sure this is not used on a production environment!", watchList);
            }

            setClassLoader(reloadingContext.getReloadingClassLoader());

            // we need to reload the context, so our isntance of the factory is
            // picked up
            reloadingContext.refresh();
        }

        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;
        }
        else if ("no".equals(autoWire))
        {
            type = AutowireCapableBeanFactory.AUTOWIRE_NO;
        }
        this.setAutowireStrategy(type);

        this.setUseClassCache(useClassCache);

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

        if (LOG.isInfoEnabled())
        {
            LOG.info("... initialized Struts-Spring integration successfully");
        }
    }
}

關鍵一步就在於第26行，那句代碼，只要使用本身的方法得到applicationContext對象就好了。而Spring對於ApplicationContext對象也提供了多種實現，既然我們想本身定義配置的名稱和位置，那麼我們就使用FileSystemXmlApplicationContext，嗯，這個類的使用就不用我贅述了。很簡單，實例化的時候將配置的路徑傳入就ok了。最後在struts的配置中，將咱們本身實現的工廠類應用上去，如：

<constant name="struts.objectFactory" value="com.xk.commons.config.XKStrutsSpringObjectFactory" />

要注意一點：代碼71行中使用到了Cla***eloadingXMLWebApplicationContext這個類，這個類的父類中會實現FilesystemAlterationListener接口，這個接口在struts和spring提供的jar包中是找不到的，其包含在apache的commons的jci庫中，具體到jar包爲commons-jci-fam-1.0.jar 下載地址：http://commons.apache.org/jci/downloads.html。