liferay中的preferences处置

liferay中的preferences处理

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在JSR168规范中，允许使用preferences来存储portlet的一些初始信息，preferences的内容在portlet.xml来设置.
在liferay中，对preferences加入了数据库持久化功能，并且可针对company, layout, portlet instance和user的不同组合来定制.

/html/portal/render_portlet.jsp? - Portlet输出页面。
?
?Portlet portlet = (Portlet)request.getAttribute(WebKeys.RENDER_PORTLET);

?CachePortlet cachePortlet = PortletInstanceFactory.create(portlet, application);

?// 读取preferences.
?PortletPreferences portletPrefs = PortletPreferencesLocalServiceUtil.getPreferences(
? company.getCompanyId(), PortletPreferencesFactory.getPortletPreferencesPK(request, portletId));

?// 创建PortletConfig.
?PortletConfig portletConfig = PortletConfigFactory.create(portlet, application);
?PortletContext portletCtx = portletConfig.getPortletContext();

?HttpServletRequest originalReq = PortalUtil.getOriginalServletRequest(request);

?// 创建RenderRequest.
?RenderRequestImpl renderRequestImpl = RenderRequestFactory.create(
? originalReq, portlet, cachePortlet, portletCtx, windowState, portletMode, portletPrefs, plid);

?StringServletResponse stringServletRes = new StringServletResponse(response);

?// 创建RenderResponse.
?RenderResponseImpl renderResponseImpl = RenderResponseFactory.create(
? renderRequestImpl, stringServletRes, portletId, company.getCompanyId(), plid);

?// setAttribute(WebKeys.JAVAX_PORTLET_CONFIG, portletConfig);
?// setAttribute(WebKeys.JAVAX_PORTLET_REQUEST, renderRequestImpl);
?// setAttribute(WebKeys.JAVAX_PORTLET_RESPONSE, renderResponseImpl);
?renderRequestImpl.defineObjects(portletConfig, renderResponseImpl);

?if (portlet.isActive() && access) {
? try {
?? cachePortlet.render(renderRequestImpl, renderResponseImpl);
? }
? catch (UnavailableException ue) {
?? portletException = true;
?? PortletInstanceFactory.destroy(portlet);
? }
?}

PortletPreferencesPK 为preferences的主键,它由portletId, layoutId和ownerId三部分标识.

com.liferay.portal.service.impl.PortletPreferencesLocalServiceImpl

?// getPreferences.
?public javax.portlet.PortletPreferences getPreferences(
??String companyId, PortletPreferencesPK pk)
?throws PortalException, SystemException {

?// 读取prefs缓存.
?Map prefsPool = PortletPreferencesLocalUtil.getPreferencesPool(
??pk.ownerId);

?PortletPreferencesImpl prefs =
??(PortletPreferencesImpl)prefsPool.get(pk);

?if (prefs == null) {
??PortletPreferences portletPreferences = null;
??// 读取portlet.
??Portlet portlet = PortletLocalServiceUtil.getPortletById(
???companyId, pk.portletId);

??try {
???// 从数据库里读preferences.
???portletPreferences =
????PortletPreferencesUtil.findByPrimaryKey(pk);
??}
??catch (NoSuchPortletPreferencesException nsppe) {
???portletPreferences = PortletPreferencesUtil.create(pk);

???if (portlet == null) {
????// 设置系统默认的preferences.
????portletPreferences.setPreferences(
?????Portlet.DEFAULT_PREFERENCES);
???}
???else {
????// 设置portlet.xml中定义的preferences.
????portletPreferences.setPreferences(
?????portlet.getDefaultPreferences());
???}

???PortletPreferencesUtil.update(portletPreferences);
??}

??prefs = PortletPreferencesSerializer.fromXML(
???companyId, pk, portletPreferences.getPreferences());

??prefsPool.put(pk, prefs);
?}

?return (PortletPreferencesImpl)prefs.clone();
?}
上面的代码首先从缓存中读取，如没有则从数据库读取，
如数据库中还没有相应的记录，则读取默认值并更新到数据库中.

另外一个获取preferences的方式是通过PortletPreferencesFactory，它提供了更方便的获取preferences的方法.

getPortalPreferences(HttpServletRequest req); // 通过HttpServletRequest获取

getPortalPreferences(ActionRequest req); // 通过ActionRequest获取

getPortalPreferences(RenderRequest req);? // 通过RenderRequest获取
在getPortalPreferences方法中，读取preferences的任务还是交给PortletPreferencesLocalServiceImpl，
只是在没有登录时，preferences被存储在httpsession中以便共享.

getPreferences(HttpServletRequest req);
与上面三个方法不同，这个方法直接读取RenderRequest的preferences.

getPreferencesValidator(Portlet portlet);
获取preferences的验证对象.

在liferay中，调用preferences的store就可以保存proferences到数据库了，

??? public void store() throws IOException, ValidatorException {
?Portlet portlet = PortletLocalServiceUtil.getPortletById(
??_companyId, _pk.portletId);

?if (!_pk.portletId.equals(PortletKeys.LIFERAY_PORTAL)) {
??PreferencesValidator prefsValidator =
???PortalUtil.getPreferencesValidator(portlet);

??????????????? // 验证数据
??if (prefsValidator != null) {
???prefsValidator.validate(this);
??}
?}

??????? // 更新preferences
?PortletPreferencesLocalServiceUtil.updatePreferences(_pk, this);
??? }

?proferences是以xml文档的方式存入数据库中的.