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import javax.portlet.ActionRequest; import javax.portlet.ActionResponse; import javax.portlet.GenericPortlet; import javax.portlet.PortletException; import javax.portlet.RenderRequest; import javax.portlet.RenderResponse; public class AdvancedPortlet extends GenericPortlet { protected void doEdit( RenderRequest renderRequest, RenderResponse renderResponse) throws PortletException, IOException { renderResponse.setContentType("text/html"); Writer writer = renderResponse.getWriter(); //get the existing parameters to use as defaults. String title = renderRequest.getParameter("title"); String contents = renderRequest.getParameter("contents"); if (title == null) { title = ""; } if (contents == null) { contents = ""; } writer.write("<H1>Portlet Settings</H1>"); writer.write("<FORM ACTION="); writer.write(renderResponse.createActionURL().toString()); writer.write(">"); writer.write( "Title: <INPUT TYPE=text NAME=title VALUE='" + title + "' SIZE=25>"); writer.write( "Contents: <INPUT TYPE=text NAME=contents VALUE= '" + contents + "' SIZE=25>");

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writer.write("<P>"); writer.write("<INPUT TYPE=submit>"); writer.write("</FORM>"); } protected void doHelp( RenderRequest renderRequest, RenderResponse renderResponse) throws PortletException, IOException { //return a helpful message renderResponse.setContentType("text/html"); Writer writer = renderResponse.getWriter(); writer.write( "This portlet allows you to change its content and title."); } protected void doView( RenderRequest renderRequest, RenderResponse renderResponse) throws PortletException, IOException { renderResponse.setContentType("text/html"); Writer writer = renderResponse.getWriter(); String contents = renderRequest.getParameter("contents"); if (contents != null) { writer.write(contents); } else { //return the default contents writer.write("This is the default portlet contents. } writer.write("<p>"); writer.write( "<IMG SRC=" + renderResponse.encodeURL( renderRequest.getContextPath() + "/images/picture.jpg") + ">"); To change "); writer.write("this message, edit the portlet's settings.");

writer.write("<p>"); writer.write( "<IMG SRC=http://www.greenninja.com/images/teton1-small.jpg>"); } protected String getTitle(RenderRequest renderRequest) { String title = renderRequest.getParameter("title"); if (title != null) { return title; } //else return a default title, if we don't have one set yet. return "Advanced Portlet"; } public void processAction( ActionRequest actionRequest, ActionResponse actionResponse) throws PortletException, IOException { //check for parameters String title = actionRequest.getParameter("title"); if (title != null) { actionResponse.setRenderParameter("title", title); } String contents = actionRequest.getParameter("contents"); if (contents != null) { actionResponse.setRenderParameter("contents", contents); } } }

Our web.xml deployment descriptor s format did not change from the first portlet, although we updated the display name and description:

< xml version="1.0" encoding="UTF-8" > <!DOCTYPE web-app PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"

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"http://java.sun.com/dtd/web-app_2_3.dtd"> <web-app> <display-name>Advanced Portlet</display-name> <description>An advanced portlet.</description> </web-app>

We packaged the advanced portlet the same way we packaged the first portlet. We also deployed the advanced portlet with the same deployment tool and command line, substituting our new WAR file s path. You will need to add the new portlet application to the portletentityregistry.xml file that we edited for the first portlet. With both portlet applications, it should look like this:

< xml version="1.0" encoding="UTF-8" > <portlet-entity-registry> <application id="first"> <definition-id>first</definition-id> <portlet id="firstportlet"> <definition-id>first.FirstPortlet</definition-id> </portlet> </application> <application id="advanced"> <definition-id>advanced</definition-id> <portlet id="advancedportlet"> <definition-id>advanced.AdvancedPortlet</definition-id> </portlet> </application> </portlet-entity-registry>

We also added the advanced portlet to the pageregistry.xml file. The portal will display the first portlet side by side with the advanced portlet:

< xml version="1.0" > <portal> <fragment name="navigation" class="org.apache.pluto.portalImpl.aggregation.navigation.TabNavigation"> </fragment> <fragment name="first" type="page"> <navigation> <title>First Portlet</title> <description>...</description>

</navigation> <fragment name="row" type="row"> <fragment name="col1" type="column"> <fragment name="p1" type="portlet"> <property name="portlet" value="first.firstportlet"/> </fragment> <fragment name="p2" type="portlet"> <property name="portlet" value="advanced.advancedportlet"/> </fragment> </fragment> </fragment> </fragment> </portal>

When you reload the portal page, you will see the portlets running next to each other in the portal page. Figure 2-2 shows both portlets running in one portal page.

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Summary

We have built two simple portlets and packaged them into portlet application archives for distribution. You can deploy either portlet application on any portal container that complies with the Portlet API 1.0 standard. We discussed the PortletRequest, PortletResponse, and GenericPortlet classes from the portlet API. We also covered several basic concepts for portlet development in this chapter. In the next chapter, we will discuss the life cycle of a portlet, including initialization, request handling, and destruction.

AS WE VE SEEN IN earlier chapters, portlets are conceptually very similar to servlets. Like servlets, they can only operate within a container. Both have obligations that their design must satisfy to allow them to interact with their container, and both demand clearly specified behavior from their containers. The portlet s obligations are, broadly speaking, to provide implementations of specific methods, to respond appropriately when these are invoked by the container, and to handle error conditions gracefully. This chapter describes the container s interactions with a portlet, starting with its creation and concluding with its destruction. It also considers the constraints that are incumbent upon both the portlet and the container at each step in this life cycle.