liferay过滤器（一）

1、Audit Filter过滤器

<filter>
  <filter-name>Audit Filter</filter-name>
  <filter-class>com.liferay.portal.servlet.filters.audit.AuditFilter</filter-class>
 </filter>

主要代码：

auditRequestThreadLocal.setClientHost(request.getRemoteHost());
  auditRequestThreadLocal.setClientIP(request.getRemoteAddr());
  auditRequestThreadLocal.setQueryString(request.getQueryString());

HttpSession session = request.getSession();

  Long userId = (Long)session.getAttribute(WebKeys.USER_ID);

  if (userId != null) {
   auditRequestThreadLocal.setRealUserId(userId.longValue());
  }

  auditRequestThreadLocal.setRequestURL(
   request.getRequestURL().toString());
  auditRequestThreadLocal.setServerName(request.getServerName());
  auditRequestThreadLocal.setServerPort(request.getServerPort());
  auditRequestThreadLocal.setSessionID(request.getSession().getId());

把客户端的主机名、IP、查询字符串和服务器端的主机名、端口号、客户访问产生的session、客户的userId放到auditRequestThreadLocal对象中。

 

2、AutoLoginFilter过滤器

<filter>
  <filter-name>Auto Login Filter</filter-name>
  <filter-class>com.liferay.portal.servlet.filters.autologin.AutoLoginFilter</filter-class>
 </filter>

主要代码：

String remoteUser = request.getRemoteUser();
  String jUserName = (String)session.getAttribute("j_username");

 String[] credentials = autoLogin.login(request, response);

     String redirect = (String)request.getAttribute(
      AutoLogin.AUTO_LOGIN_REDIRECT);

     if (Validator.isNotNull(redirect)) {
      response.sendRedirect(redirect);

      return;
     }

     String loginRemoteUser = getLoginRemoteUser(
      request, response, session, credentials);

     if (loginRemoteUser != null) {
      request = new ProtectedServletRequest(
       request, loginRemoteUser);

      if (PropsValues.PORTAL_JAAS_ENABLE) {
       return;
      }

      redirect = (String)request.getAttribute(
       AutoLogin.AUTO_LOGIN_REDIRECT_AND_CONTINUE);

      if (Validator.isNotNull(redirect)) {
       response.sendRedirect(redirect);

       break;
      }
     }

 

取得登陆的用户信息，如果用户信息正确，自动跳转到登陆页面，为空则重定向。

 

3、Cache Filter - Friendly过滤器

<filter>
  <filter-name>Cache Filter - Friendly</filter-name>
  <filter-class>com.liferay.portal.servlet.filters.cache.CacheFilter</filter-class>
  <init-param>
   <param-name>pattern</param-name>
   <param-value>0</param-value>
  </init-param>
 </filter>

参数pattern：0、PATTERN_FRIENDLY；1、PATTERN_LAYOUT；2、PATTERN_RESOURCE

主要代码：

request.setAttribute(SKIP_FILTER, Boolean.TRUE);

   String key = getCacheKey(request);

   long companyId = PortalInstances.getCompanyId(request);

   CacheResponseData cacheResponseData =
    CacheUtil.getCacheResponseData(companyId, key);

   if (cacheResponseData == null) {
    if (!isCacheableData(companyId, request)) {
     if (_log.isDebugEnabled()) {
      _log.debug("Request is not cacheable " + key);
     }

     processFilter(
      CacheFilter.class, request, response, filterChain);

     return;
    }

    if (_log.isInfoEnabled()) {
     _log.info("Caching request " + key);
    }

    StringServletResponse stringResponse =
     new StringServletResponse(response);

    processFilter(
     CacheFilter.class, request, stringResponse, filterChain);

    cacheResponseData = new CacheResponseData(stringResponse);

    LastPath lastPath = (LastPath)request.getAttribute(
     WebKeys.LAST_PATH);

    if (lastPath != null) {
     cacheResponseData.setAttribute(WebKeys.LAST_PATH, lastPath);
    }

    // Cache the result if and only if there is a result and the
    // request is cacheable. We have to test the cacheability of a
    // request twice because the user could have been authenticated
    // after the initial test.

    if (isCacheableRequest(request) &&
     isCacheableResponse(stringResponse)) {

     CacheUtil.putCacheResponseData(
      companyId, key, cacheResponseData);
    }
   }
   else {
    LastPath lastPath = (LastPath)cacheResponseData.getAttribute(
     WebKeys.LAST_PATH);

    if (lastPath != null) {
     HttpSession session = request.getSession();

     session.setAttribute(WebKeys.LAST_PATH, lastPath);
    }
   }

   CacheResponseUtil.write(response, cacheResponseData);

 

首先判断是否支持缓存，如果支持，判断缓存中是否有数据，如果有数据直接把数据写到response中，如果没有，判断有没有companyId,如果有，从response中取数据过滤，最后放到cacheResponseData中。

 

 4、Double Click Filter过滤器

<filter>
  <filter-name>Double Click Filter</filter-name>
  <filter-class>com.liferay.portal.servlet.filters.doubleclick.DoubleClickFilter</filter-class>
 </filter>

主要代码：

DoubleClickController controller = null;

   synchronized (session) {
    controller = (DoubleClickController)session.getAttribute(
     _CONTROLLER_KEY);

    if (controller == null) {
     controller = new DoubleClickController();

     session.setAttribute(_CONTROLLER_KEY, controller);
    }
   }

如果属性com.liferay.filters.doubleclick.DoubleClickFilter=true，则处理在服务器端阻止鼠标双击。

 

5、ETag Filter过滤器

<filter>
  <filter-name>ETag Filter</filter-name>
  <filter-class>com.liferay.portal.servlet.filters.etag.ETagFilter</filter-class>
  <init-param>
   <param-name>url-regex-ignore-pattern</param-name>
   <param-value>.+/-/.+</param-value>
  </init-param>
 </filter>

主要代码：

boolean etag = ParamUtil.getBoolean(request, _ETAG, true);

  if (etag) {
   StringServletResponse stringResponse =
    new StringServletResponse(response);

   processFilter(
    ETagFilter.class, request, stringResponse, filterChain);

   if (!ETagUtil.processETag(request, response, stringResponse)) {
    ServletResponseUtil.write(response, stringResponse);
   }
  }
  else {
   processFilter(ETagFilter.class, request, response, filterChain);
  }

 

ETag Filter是一个servlet过滤器，是用来帮助判断服务器端的有没有跟新，即刷新页面时判断是否需要更新缓存。

 

6、Fragment Filter过滤器

主要代码：

if (isFragment(request, response) && !isAlreadyFiltered(request)) {
   request.setAttribute(SKIP_FILTER, Boolean.TRUE);

   if (_log.isDebugEnabled()) {
    String completeURL = HttpUtil.getCompleteURL(request);

    _log.debug("Fragmenting " + completeURL);
   }

   StringServletResponse stringServerResponse =
    new StringServletResponse(response);

   processFilter(
    FragmentFilter.class, request, stringServerResponse,
    filterChain);

   String content = getContent(
    request, stringServerResponse.getString());

   ServletResponseUtil.write(response, content);
  }
  else {
   if (_log.isDebugEnabled()) {
    String completeURL = HttpUtil.getCompleteURL(request);

    _log.debug("Not fragmenting " + completeURL);
   }

   processFilter(FragmentFilter.class, request, response, filterChain);
  }

protected String getContent(HttpServletRequest request, String content) {
  String fragmentId = ParamUtil.getString(request, "p_f_id");

  int x = content.indexOf("<!-- Begin fragment " + fragmentId + " -->");
  int y = content.indexOf("<!-- End fragment " + fragmentId + " -->");

  if ((x == -1) || (y == -1)) {
   return content;
  }

  x = content.indexOf(">", x);

  return content.substring(x + 1, y);
 }

 

把response里面的portalet产生的内容，也被称为片段 (fragment），进行过滤（即把头和尾去掉），然后写到response中