客製Portlet 產生RSS Feed的做法

環境Liferay6.2.1 + tomcat-7.0.42 + JAVA 7

使用postgreSQL 9版

本例以新聞發布為例。

先在 liferay-plugin-package.properties

加入 jdom.jar , dom4j.jar , rome.jar  這三個jar檔主要是用來產生RSS Feed。

連XML template都不用自己建。

如果沒有載入，<liferay-ui:rss> 與 <liferay-ui:rss-settings> 這兩個Tag會產生null的Exception。

portal-dependency-jars=\

    jstl-api.jar,\

    jstl-impl.jar,\

    jdom.jar,\

    dom4j.jar,\

    rome.jar

這是這次所使用的model 

<service-builder package-path="com.xxx.portlet">

<author>Danny</author>

<namespace>news</namespace>

<entity name="News" human-name="news" local-service="true"

remote-service="false" uuid="true">

<column name="newsId" type="long" primary="true" />

<column name="groupId" type="long" />

<column name="companyId" type="long" />

<column name="userId" type="long" />

<column name="userName" type="String" />

<column name="modifiedDate" type="Date" />

<column name="createDate" type="Date" />

<column name="title" type="String" />

<column name="content" type="String" />

<column name="viewCount" type="long" />

<column name="priority" type="boolean" />

<column name="category" type="String" />

<column name="copyToMainSite" type="boolean" />

<column name="urlTitle" type="String" />

    <column name="resourcePrimKey" type="long"/>

   <column name="status" type="int"/>

   <column name="statusByUserId" type="long"/>

   <column name="statusByUserName" type="String"/>

   <column name="statusDate" type="Date"/>

<order by="desc">

<order-column name="createDate" />

</order>

<finder name="CD_T" return-type="Collection">

<finder-column name="createDate" comparator="&gt;"/>

<finder-column name="title" comparator="LIKE"/>

</finder>

<finder name="CD_C" return-type="Collection">

<finder-column name="createDate" comparator="&gt;"/>

<finder-column name="content" comparator="LIKE"/>

</finder>

<finder name="R_S" return-type="Collection">

  <finder-column name="resourcePrimKey"/>

  <finder-column name="status"/>

</finder>

<finder name="GroupId" return-type="Collection">

<finder-column name="groupId" />

</finder>

<finder name="CompanyId" return-type="Collection">

<finder-column name="companyId" />

</finder>

<finder name="G_UT" return-type="News" unique="true">

<finder-column name="groupId" />

<finder-column name="urlTitle" />

</finder>

<finder name="G_NotS" return-type="Collection">

<finder-column name="groupId" />

<finder-column name="status" comparator="!=" />

</finder>

<finder name="G_S" return-type="Collection">

<finder-column name="groupId" />

<finder-column name="status" />

</finder>

<reference package-path="com.liferay.portal" entity="Group" />

<reference package-path="com.liferay.portal" entity="WorkflowInstanceLink"/>

<reference package-path="com.liferay.portlet.asset" entity="AssetEntry" />

<reference package-path="com.liferay.portlet.asset" entity="AssetLink" />

<reference package-path="com.liferay.portlet.asset" entity="AssetTag" />

</entity>

</service-builder>

在init.jsp 上加入以下這幾四個參數，這是使用<liferay-ui:rss>所需要使用到的參數。

boolean enableRSS = !PortalUtil.isRSSFeedsEnabled() ? false : GetterUtil.getBoolean(portletPreferences.getValue("enableRss", null), true);

int rssDelta = GetterUtil.getInteger(portletPreferences.getValue("rssDelta", StringPool.BLANK), SearchContainer.DEFAULT_DELTA);

String rssDisplayStyle = portletPreferences.getValue("rssDisplayStyle", RSSUtil.DISPLAY_STYLE_DEFAULT);

String rssFeedType = portletPreferences.getValue("rssFeedType", RSSUtil.FEED_TYPE_DEFAULT);

latestnews_view.jsp 就可以使用 rss的Tag了。

<liferay-portlet:resourceURL varImpl="rssURL" >

</liferay-portlet:resourceURL>

        <liferay-ui:rss

delta="<%= rssDelta %>"

displayStyle="<%= rssDisplayStyle %>"

feedType="<%= rssFeedType %>"

resourceURL="<%= rssURL %>" />

如以下，就會產生RSS的超連結出來。

當點下之後，會去呼叫 resourceURL。

就會導到Control的 public void serveResource(ResourceRequest request, ResourceResponse response)

方法。

在這裡取得RSS Feed的做法也就是在這裡開始產生。

如果是Struts的作法，就要去繼承 Struts.RSSAction.java 然後在裡面實作。

在這裡我們是採用MVCPortlet.java

public class NewsPortlet extends MVCPortlet{

@Override

public void serveResource(ResourceRequest request, ResourceResponse response)

            throws PortletException, IOException {

response.setContentType(ContentTypes.TEXT_XML_UTF8);

ThemeDisplay themeDisplay = (ThemeDisplay)request.getAttribute(

WebKeys.THEME_DISPLAY);

Layout layout = themeDisplay.getLayout();

long plid = themeDisplay.getPlid();

long groupId = themeDisplay.getScopeGroupId();

int max = ParamUtil.getInteger(request, "max", SearchContainer.DEFAULT_DELTA);

String type = ParamUtil.getString(request, "type", RSSUtil.FORMAT_DEFAULT);

double version = ParamUtil.getDouble(request, "version", RSSUtil.VERSION_DEFAULT);

String displayStyle = ParamUtil.getString(request, "displayStyle", RSSUtil.DISPLAY_STYLE_DEFAULT);

String feedURL = themeDisplay.getPortalURL() + themeDisplay.getPathMain() +

"/news/find_entry?";

_log.info("themeDisplay.getPortalURL():" + themeDisplay.getPortalURL() + "==");

_log.info("themeDisplay.getPathMain():" + themeDisplay.getPathMain() + "==");

String entryURL = feedURL;

String rss = StringPool.BLANK;

try {

if (layout != null) {

groupId = themeDisplay.getScopeGroupId();

feedURL = PortalUtil.getLayoutFullURL(themeDisplay) +

Portal.FRIENDLY_URL_SEPARATOR + "news/rss";

_log.info("feedURL:" + feedURL + "==");

entryURL = feedURL;

rss = NewsLocalServiceUtil.getGroupNewsesRSS(

groupId, max, type, version, displayStyle,

feedURL, entryURL, themeDisplay);

}

} catch (SystemException e) {

e.printStackTrace();

} catch (PortalException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

// return rss.getBytes(StringPool.UTF8);

PrintWriter writer = response.getWriter();

writer.print(rss);

}

}

這當中有去呼叫到 NewsLocalServiceUtil.getGroupNewsesRSS();

這是自己定義的method。

所以在NewsLocalServiceImpl.java內要實作這個method

 public String getGroupNewsesRSS(

long groupId, int max, String type,

double version, String displayStyle, String feedURL,

String entryURL, ThemeDisplay themeDisplay)

throws PortalException, SystemException {

Group group = groupPersistence.findByPrimaryKey(groupId);

String name = group.getDescriptiveName();

List<News> newses = getGroupNewses(groupId, 0, max);

return exportToRSS(

name, name, type, version, displayStyle, feedURL, entryURL,

newses, themeDisplay);

}

 

protected String exportToRSS(

String name, String description, String type, double version,

String displayStyle, String feedURL, String entryURL,

List<News> newses, ThemeDisplay themeDisplay)

throws SystemException {

SyndFeed syndFeed = new SyndFeedImpl();

syndFeed.setDescription(description);

List<SyndEntry> syndEntries = new ArrayList<SyndEntry>();

syndFeed.setEntries(syndEntries);

for (News news : newses) {

SyndEntry syndEntry = new SyndEntryImpl();

String author = PortalUtil.getUserName(news);

syndEntry.setAuthor(author);

SyndContent syndContent = new SyndContentImpl();

syndContent.setType(RSSUtil.ENTRY_TYPE_DEFAULT);

String value = null;

if (displayStyle.equals(RSSUtil.DISPLAY_STYLE_ABSTRACT)) {

String summary = news.getTitle();

if (Validator.isNull(summary)) {

summary = StringUtil.shorten(

HtmlUtil.extractText(news.getContent()),

200, StringPool.BLANK);

}

value = StringUtil.shorten(

HtmlUtil.extractText(summary),

200, StringPool.BLANK);

}

else if (displayStyle.equals(RSSUtil.DISPLAY_STYLE_TITLE)) {

value = StringPool.BLANK;

}

else {

value = StringUtil.replace(

news.getContent(),

new String[] {

"href=\"/", "src=\"/"

},

new String[] {

"href=\"" + themeDisplay.getURLPortal() + "/",

"src=\"" + themeDisplay.getURLPortal() + "/"

});

}

syndContent.setValue(value);

syndEntry.setDescription(syndContent);

StringBundler sb = new StringBundler(4);

if (entryURL.endsWith("/news/rss")) {

sb.append(entryURL.substring(0, entryURL.length() -11 ));

sb.append(StringPool.QUESTION);

sb.append("p_p_id=");

sb.append(PortletKeys.LATESTNEWS_PORTLET);

sb.append(StringPool.AMPERSAND); //&

sb.append("p_p_lifecycle=0&p_p_state=normal&p_p_mode=view&p_p_col_id=column-1&p_p_col_count=1&");

sb.append(PortletKeys.NEWS_NAMESPACE + "jspPage=");

sb.append("%2Fhtml%2Fnews%2Flatestnews_view.jsp");

sb.append(StringPool.AMPERSAND); //&

sb.append(PortletKeys.NEWS_NAMESPACE + "newsId=");

sb.append(news.getNewsId());

_log.info("if=>sb:" + sb + "==");

}

else {

sb.append(entryURL);

_log.info("else=>sb:" + sb + "==");

if (!entryURL.endsWith(StringPool.QUESTION)) {

sb.append(StringPool.AMPERSAND);

}

}

String link = sb.toString();

syndEntry.setLink(link);

syndEntry.setPublishedDate(news.getCreateDate());

syndEntry.setTitle(news.getTitle());

syndEntry.setUpdatedDate(news.getModifiedDate());

syndEntry.setUri(link);

syndEntries.add(syndEntry);

}

syndFeed.setFeedType(RSSUtil.getFeedType(type, version));

List<SyndLink> syndLinks = new ArrayList<SyndLink>();

syndFeed.setLinks(syndLinks);

SyndLink selfSyndLink = new SyndLinkImpl();

syndLinks.add(selfSyndLink);

selfSyndLink.setHref(feedURL);

selfSyndLink.setRel("self");

if (feedURL.endsWith("/-/news/rss")) {

SyndLink alternateSyndLink = new SyndLinkImpl();

syndLinks.add(alternateSyndLink);

alternateSyndLink.setHref(

feedURL.substring(0, feedURL.length() - 11));

alternateSyndLink.setRel("alternate");

}

syndFeed.setPublishedDate(new Date());

syndFeed.setTitle(name);

syndFeed.setUri(feedURL);

try {

return RSSUtil.export(syndFeed);

}

catch (FeedException fe) {

throw new SystemException(fe);

}

}

當中的entryURL 和 FeedURL 是比較難搞的，

FeedURL = 消息來源網址。

entryURL = 消息來源之內部每單一筆的導向網址，點擊RSS其中一筆後，會開啟該篇新聞的來源網址。

上面每一筆的entryURL 都是仿照PortletURL在網址上的參數，

有用到portletKeys，我是這樣寫，

public static final String LATESTNEWS_PORTLET = "News_WAR_Newsportlet";

public static final String NEWS_NAMESPACE = "_News_WAR_Newsportlet_";

portletId 與 namespace的差別 在於 左右兩側的底線。

另外這是設定RSS的型態，可以寫在Portlet-Configuration上。

<%@include file="/html/init.jsp"%>

<liferay-portlet:actionURL portletConfiguration="true"

var="configurationURL" />

<aui:form action="<%=configurationURL%>" method="post">

<aui:input name="<%=Constants.CMD%>" type="hidden"

value="<%=Constants.UPDATE%>" />

<aui:fieldset>

<liferay-ui:rss-settings

delta="<%= rssDelta %>"

displayStyle="<%= rssDisplayStyle %>"

enabled="<%= enableRSS %>"

feedType="<%= rssFeedType %>"/>

<aui:button type="submit" />

</aui:fieldset>

</aui:form>