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Converting IBM portlets

You can convert your basic IBM portlets as well as IBM portlets that use the Struts Portlet Framework to the standard portlet API.


Converting basic IBM portlets to the standard

This topic describes some of the more common changes (but not all) that are required to convert an IBM portlet to a standard portlet. Many conversion tasks depend on the amount of complexity in the portlet code. You will have to become familiar with the Java Portlet Specification to determine any remaining changes that are not covered in this topic.

Changing Java source

  1. Change import statements to use the standard packages. Change this: 

        import org.apache.jetspeed.portlet.*; 
    import org.apache.jetspeed.service.*;
    to this: 

        import javax.portlet.*;
    import com.ibm.portal.portlet.service.*;

  2. Change class inheritance to use GenericPortlet. Notice that the ActionListener is not implemented. Change this: 

        public class SamplePortlet extends PortletAdapter implements ActionListener{  
    ...
    }
    to this: 

        public class SamplePortlet extends GenericPortlet{
    ...
    }

  3. Change objects used for all render methods. In the standard portlet API, the PortletRequest and PortletResponse define common functionality for the RenderRequest and RenderResponse subclasses. These subclasses are the arguments for all implementations of the render() method, including doView(), doEdit(), and doHelp(). Change this: 

      public void doView(PortletRequest request, PortletResponse response) {  
     ...
  }
    to this: 

      public void doView(RenderRequest request, RenderResponse response)
       throws PortletException, IOException{
       ...
  }

  4. Change the actionPerformed() method. In the standard portlet API, this method is replaced by the processAction() method, which does not require the portlet to implement a listener. The processAction() methods accepts the ActionRequest and ActionResponse as arguments, which extend the PortletRequest and PortletResponse. Change this: 

        public void actionPerformed(ActionEvent event) throws PortletException{  
    ...
    }
    to this: 

      public void processAction(ActionRequest request, ActionResponse response)  
       throws PortletException, IOException{
       ...
  }

  5. Change how the response content type is set. In the standard portlet API, the MIME type of the output returned in the response must be set before including the JSP. IBM portlets declare the MIME type using the contentType attribute of JSP's page directive. Therefore, this change makes the contentType setting in the JSP unnecessary. Add this before including the JSP: 

    response.setContentType("text/html");

  6. Change JSP includes. In the standard portlet API, JSPs are included by a request dispatcher's include() method. In the portlets' render method, set the MIME type of the output before returning it in the response. Change this: 

    

    PortletContext context = getPortletConfig().getContext();
    context.include("/jsp/View.jsp", request, response);
    to this: 

        response.setContentType("text/html");


    PortletContext context = getPortletConfig().getPortletContext();
    context.getRequestDispatcher("/jsp/View.jsp").include( request, response);

  7. Change classes where user data is stored. In the standard portlet API, user data is stored in a PortletPreferences object, rather than the PortletData object that is available using the IBM portlet API. Notice the different getter methods used with the request object and setter methods used for the data object. Change this: 

            PortletData portData = request.getData();
        portData.setAttribute("userName", userName);
        portData.store();
    to this: 

            PortletPreferences prefs = request.getPreferences();
        prefs.setValue("userName",request.getParameter("username"));  
        prefs.store();

    Some preferences are read-only and can be modified only by an administrator. See Change configuration parameters to preferences for more information.

  8. Change the method used for namespace encoding.

    For example, if the portlet uses encodeNamespace() to return a unique string to be prefixed to a JavaScript variable name within the content generated by the portlet, the portlet should now use getNamespace(). Change this: 

            PortletResponse.encodeNamespace()
    to this: 

            RenderResponse.getNamespace()

  9. Change how portlet URLs are generated.

    For example, a portlet's doEdit() method might save the URI to the edit mode to pass to the JSP. The portlet must instantiate a PortletURL object using the createRenderURL() method. Change this: 

          // Save URI for the edit page
      PortletURI editURI = response.createURI();
      ...
      // Preserve the edit page URI in the request to make 
      // it accessible by the edit JSP  
      request.setAttribute("editURI", editURI.toString());
    to this: 

          // Save URI for the edit page
      PortletURL editURL = response.createRenderURL();
      ...
      // Preserve the edit page URI in the request 
      // to make it accessible by the edit JSP  
      request.setAttribute("editURL", editURL.toString());

    The standard portlet API does not have an equivalent method for createReturnURI(). If the URL is intended to call the portlets' action method, however, the portlet should use the createActionURL() method.

Changing JSP source

  1. Change the tag library to use the standard tag library. Change this: 

        <%@ taglib uri="/WEB-INF/tld/portlet.tld" prefix="portletAPI" %>
    to this: 

        <%@ taglib uri="http://java.sun.com/portlet" prefix="portlet" %>

  2. Change references to API objects. In the standard portlet API, the <portlet:defineObjects /> JSP tag makes the RenderRequest, RenderResponse, and PortletConfig objects available to JSP files.

    After making this change, all references in the JSP to the PortletRequest and PortletResponse should be changed to the corresponding RenderRequest and RenderResponse. Change this: 

        <portletAPI:init /> 
    ...
    <%


    PortletData prefs = portletRequest.getData();
    %>
    to this: 

       <portlet:defineObjects /> 
   ...
   <%


    PortletPreferences prefs = renderRequest.getPreferences();
   %>

  3. Change JSP tags used for namespace encoding.

    For example, if the portlet uses <portletAPI:encodeNamespace/> to uniquely qualify the name of a text input field, this tag must be changed as follows.

    Change this: 

       <input name="<portletAPI:encodeNamespace value='name'/>"  type="text" >
    to this: 

       <input name="<portlet:namespace/>name"  type="text" >

  4. Change how portlet URLs are generated. If the portlet JSP creates a URL to itself, it should specify which method gets control using the <portlet:actionURL/> or <portlet:renderURL/> tags. Any parameters passed on the URL are specified using the <portlet:param/> tag. Change this: 

       <a href="<portletAPI:createURI>
               <portlet:URIParameter name='action' value='search'/>   
            </portlet:createURI>" >
    to this: 

       <a href="<portlet:actionURL>
               <portlet:param name='action' value='search'/>
            </portlet:actionURL>" >

  5. Change resource bundles. The <portletAPI:text/> tag of the IBM Portlet API has been deprecated and should be replaced in all portlets by the JSTL equivalent. See Use JSTL in portlet JSPs for more information. Change this: 

        <portletAPI:text key="my.label" bundle="nls.myproperties"/>
    to this: 

        <fmt:setBundle basename="nls.myproperties"/>
    ...
    <fmt:message key="my.label"/>

  6. Change how resources are invoked from the JSP.

    For example, if the JSP displays an image, it should use the encodeURL() method of the appropriate response object and, in addition, add the context path of the portlet from the request. Change this: 

      <img src='<%= portletResponse.encodeURL("images/photo01.jpg") %>' 
    >
    to this: 

    <img src='<%= renderResponse.encodeURL(renderRequest.getContextPath() + 
              "/images/photo01.jpg") %>' >

Changing the portlet deployment descriptor

The following steps describe some of the differences between the portlet deployment descriptors of the IBM Portlet API and the Java Portlet Specification. However, the order of the elements in the standard portlet descriptor is important and strictly enforced during deployment. You should use a tool, such as Rational Application Developer, that performs validation as you develop the portlet deployment descriptor.

  1. Remove the DOCTYPE declaration. The portlet descriptor for the standard portlets uses an XML schema, which will be added in the next step. Remove this: 

    <!DOCTYPE portlet-app-def PUBLIC "-//IBM//DTD Portlet Application 1.1//EN"
              "portlet_1.1.dtd ">

  2. Remove the <portlet-app-def/> element. The top level element in the standard portlet descriptor is <portlet-app/>. Remove this: 

        <portlet-app-def>    
    ....
    </portlet-app-def>

  3. Update the <portlet-app/> element.

    • Add the schema definition and namespace declarations.

    • Remove the major-version and minor-version attributes.

    • Set the version attribute to the required version of the Java Portlet Specification. Currently, version 1.0 is the only supported specification version.

    • Change the uid attribute to id.

    Change this: 

       <portlet-app uid="com.mycompany.samples.MyPortletApp.001c" 
                major-version="1" minor-version="0">
    to this: 

    <portlet-app 
     xmlns="http://java.sun.com/xml/ns/portlet/portlet-app_1_0.xsd" 
     version="1.0" 
     id="com.mycompany.samples.MyPortletApp.001c"
     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" 
     xsi:schemaLocation=
        "http://java.sun.com/xml/ns/portlet/portlet-app_1_0.xsd 
         http://java.sun.com/xml/ns/portlet/portlet-app_1_0.xsd">

  4. Remove all <concrete-portlet-app/> elements and their contents. Save any required information, such as configuration parameters and language definitions, for use in the portlet definition.

  5. Update the <portlet/> element. Remove the href, minor-version, and major-version attributes. Change this: 

       <portlet id="com.mycompany.samples.MyPortlet.110x" 
            href="WEB-INF/web.xml#com.mycompany.samples.MyPortlet.href110x"   
            major-version="1" minor-version="0">
    to this: 

       <portlet id="com.mycompany.samples.MyPortlet.110x">

  6. Move the definition of the portlet class from the web.xml to the portlet.xml. Remove this from the web.xml: 

        <servlet id="com.mycompany.samples.MyPortlet.001c">
        <servlet-name>MyPortlet</servlet-name>
        <servlet-class>com.mycompany.samples.MyPortlet</servlet-class>
    </servlet>
    <servlet-mapping 
             id="ServletMapping_com.mycompany.samples.MyPortlet.001c">  
        <servlet-name>MyPortlet</servlet-name>
        <url-pattern>/MyPortlet/*</url-pattern>
    </servlet-mapping>

    Add this to the portlet.xml: 

            <portlet-class>com.mycompany.samples.MyPortlet</portlet-class>

  7. Change how caching is defined. Use the <expires/> value from the IBM portlet descriptor as the value for the <expiration-cache/> element in the standard descriptor. There is no equivalent in the standard descriptor to the <shared/> element. See Caching portlet output for more information. Change this: 

        <cache>
       <expires>-1</expires>
       <shared>no</shared>
    </cache>
    to this: 

        <expiration-cache>-1</expiration-cache>

  8. Change the content of the <supports/> element.

    • Change supported markups to MIME types.

    • Use the <portlet-mode/> element.

    The standard portlet descriptor allows you to declare only MIME types. In some cases, two markup types use the same MIME type.

    For example, both HTML and cHTML use 'text/html' as the MIME type.

    For standard portlets, WebSphere Portal accepts the value of a wps.markup initialization parameter as the markup type.

    Change this: 

        <supports>
       <markup name="html">
          <view />
          <edit />
       </markup>
    </supports>
    to this: 

        <init-param>
       <name>wps.markup</name>
       <value>html,chtml</value>
    </init-param>
    ...
    <supports>
       <mime-type>text/html</mime-type>
       <portlet-mode>VIEW</portlet-mode>   
       <portlet-mode>EDIT</portlet-mode>
    </supports>

    Be sure to place the initialization parameters before the <expiration-cache> element.

  9. Remove window state elements. Normal, maximized, and minimized window states are supported by default and not declared in the standard portlet deployment descriptor.Remove this: 

        <allows>
       <maximized/>   
       <minimized/>
    </allows>

  10. Change configuration parameters to preferences.

    In the standard portlet descriptor, preferences can be changed by users in any of the standard modes, or they can be declared as read-only and modified only by an administrator. Change this: 

              <config-param>
              <param-name>Location</param-name>
              <param-value>Antartica</param-value>
          </config-param>
    to this: 

          <portlet-preferences>
            <preference>
                <name>Location</name>
                <value>Antartica</value>
                <read-only>true</read-only>
            </preference>
      </portlet-preferences>

  11. Change localized settings.

    1. Remove the <default-locale/> element. In the standard portlet descriptor, the first locale listed in the descriptor is the default.

      If no locale is specified, then English is used as the default.

    2. Create resource bundles for each supported language containing the title, short title, and keywords for the portlet. Use the following parameter names: 

          javax.portlet.title = My Portlet Title
    javax.portlet.short-title = Title
    javax.portlet.keywords = portlets, JSR 168, portal

    3. Declare the resource bundle in the portlet descriptor as in the following example. 

          <resource-bundle>nls.MyPortlet</resource-bundle>

      In this example, the default resource bundle MyPortlet.properties is in the /WEB-INF/nls subdirectory of the WAR file and all of the locale-specific resource bundles append the locale to the filename (for example, MyPortlet_ja.properties for Japanese).

    4. Declare each supported locale as in the following example: 

          <supported-locale>en</supported-locale>
    <supported-locale>de</supported-locale>

    5. Set the localized values for the portlet description and display name as in the following example. 

      <description xml:lang="EN">


      English description
</description>
<display-name xml:lang="EN">


      English display name
</display>-name>
<description xml:lang="DE">


      German description
</description>
<display-name xml:lang="DE">


      German display name
</display>-name>

      The display name should be set for compatibility reasons. However, it is not currently used by WebSphere Portal.


Converting IBM portlets that use the Struts Portlet Framework

The existing versions of the Struts Portlet Framework supported the IBM Portal container API, or the legacy container. This release uses a newer version of the Struts Portlet Framework that supports the standard portlet container. This release will continue to ship a version to support the legacy container and a new version for the Standard container. The Struts Portlet Framework is still shipped as example war files that can be used to build the Struts application. The war files for each container can be distinguished by the name. The SPFLegacy examples support the legacy container, and the SPFStandard examples support the standard container. The SPFLegacyBlank.war is the starting point for Struts applications for the Legacy container, and the SPFStandardBlank is the starting point for the Struts applications for the Standard container.

The Struts Portlet Framework for the Legacy Container

The SPFLegacyBlank.war includes the files to be included with the Struts application. The directories of interest are the WEB-INF/lib and the WEB-INF/tld directory. Here is the list of libraries to be used in the application from the WEB-INF/lib directory:

  1. PortalStruts.jar

  2. PortalStrutsCommon.jar

  3. PortalStrutsTags.jar

  4. StrutsUpdateForPortal.jar

  5. wp.struts-commons-logging.jar

  6. commons-beanutils.jar

  7. commons-collections.jar

  8. commons-fileupload.jar

  9. commons-lang.jar

  10. commons-validator.jar

  11. struts-legacy.jar

  12. struts.jar

The files from the TLD directory are

  1. struts-bean.tld

  2. struts-chtml.tld

  3. struts-html.tld

  4. struts-logic.tld

  5. struts-nested.tld

  6. struts-portal-html.tld

  7. struts-portal-wml.tld

  8. struts-template.tld

  9. struts-tiles.tld

  10. struts-wml.tld

The Struts Portlet Framework for the Standard Container

The SPFStandardBlank.war includes the files to be included in the Struts application. The directories of interest are the WEB-INF/lib and the WEB-INF/tld directory. Here is the list of libraries to be used in the application from the WEB-INF/lib directory.

  1. wp.struts.standard.framework.jar

  2. PortalStrutsCommon

  3. PortalStrutsTags.jar

  4. StrutsUpdateForPortal.jar

  5. wp.struts-commons-logging.jar

  6. commons-beanutils.jar

  7. commons-collections.jar

  8. commons-fileupload.jar

  9. commons-lang.jar

  10. commons-validator.jar

  11. struts-legacy.jar

  12. struts.jar

The files from the TLD directory are:

  1. struts-bean.tld

  2. struts-chtml.tld

  3. struts-html.tld

  4. struts-logic.tld

  5. struts-nested.tld

  6. struts-portal-html.tld

  7. struts-portal-wml.tld

  8. struts-template.tld

  9. struts-tiles.tld

  10. struts-wml.tld

Files common to both the standard and IBM portlet containers

The following files are the Jakarta Struts 1.1 binaries, and the same in both the Standard and Legacy versions of the Struts Portlet Framework:

  1. commons-beanutils.jar

  2. commons-collections.jar

  3. commons-fileupload.jar

  4. commons-lang.jar

  5. commons-validator.jar

  6. struts-legacy.jar

  7. struts.jar

The following files from the TLD directory are same on for both containers. This can change in future releases, so it is strongly encouraged to use the files from the blank for the desired container.

  1. struts-bean.tld

  2. struts-chtml.tld

  3. struts-html.tld

  4. struts-logic.tld

  5. struts-nested.tld

  6. struts-portal-html.tld

  7. struts-portal-wml.tld

  8. struts-template.tld

  9. struts-tiles.tld

  10. struts-wml.tld

Conversion to the Standard Version of the Struts Portlet Framework from previous versions of the Struts Portlet Framework

Converting the legacy version of the Struts Portlet Framework to the Standard versions starts with updating the jars, and TLDs shipped with the SPFStandardBlank.war file. Here is a list of the files that should be updated in the WEB-INF/lib directory of the application:

  1. wp.struts.standard.framework.jar

  2. PortalStrutsCommon.jar

  3. PortalStrutsTags.jar

  4. StrutsUpdateForPortal.jar

  5. wp.struts-commons-logging.jar

  6. commons-beanutils.jar

  7. commons-collections.jar

  8. commons-fileupload.jar

  9. commons-lang.jar

  10. commons-validator.jar

  11. struts-legacy.jar

  12. struts.jar

  13. commons-digester.jar

  14. commons-logging.jar

  15. jakarta-oro.jar

Here is a list of the TLD files that should be updated with the TLDs from the SPFStandardBlank.war file:

  1. struts-bean.tld

  2. struts-chtml.tld

  3. struts-html.tld

  4. struts-logic.tld

  5. struts-nested.tld

  6. struts-portal-html.tld

  7. struts-portal-wml.tld

  8. struts-template.tld

  9. struts-tiles.tld

  10. struts-wml.tld

The following JAR file is only required on the IBM container and must be deleted:

  1. PortalStruts.jar

Web Deployment Descriptor

The Standard container requires a Web deployment descriptor because the application is packaged as a war file. However, most of the initialization parameters are now configured through the portlet deployment descriptor.

  1. Remove the servlet class from the Web deployment descriptor. The servlet-class is no longer that way to specify the portlet class for the application in the Standard container. The portlet is now specified as the portlet class in the portlet deployment descriptor.

  2. Move the init parameters from the Web deployment descriptor to the portlet deployment descriptor. Since the portlet class is now defined in the portlet deployment descriptor, the init parameters are also specified in the portlet deployment descriptor. Note, the init-parameter are specified as name and value in the portlet deployment descriptor, not param-name and param-value as they are named in the Web deployment descriptor.

  3. The taglib elements still remain in the Web deployment descriptor, no changes required.

  4. The welcome file elements still remain in the Web deployment descriptor, no changes required.

Portlet Deployment Descriptor

The definition for the Portlet Deployment Descriptor for the Standard container is different from the legacy container. There are some changes required for the converted example to deploy in the Standard container. The information center contains details for the semantics of the portlet deployment descriptor for the Standard container.

  1. The Standard container introduces the portlet-class element for specifying the class of the portlet. The portlet class for the Struts Portlet Framework is com.ibm.portal.struts.portlet.StrutsPortlet.

  2. The init parameters for the portlet are defined in the portlet deployment descriptor. The init parameters should be converted from the Web deployment descriptor.

  3. The Standard container does not have the abstract and concrete separation in the portlet deployment descriptor. The portlet element defines the supported modes, and portlet preferences.

  4. The Struts Portlet Framework no longer uses a portlet filter.

    The FilterChain init-parameter should not be converted.

Struts Configuration File

The Struts Portlet Framework defines the Request Processor that must be configured in the Struts configuration file. The controller attribute processClass needs to be converted to the following value to be deployed on the Standard container: <controller processorClass="com.ibm.portal.struts.portlet.WpRequestProcessor">

If the Struts application is using the Struts Request processor that supports Tiles, then the Struts plug-in needs to be converted as well: <plug-in className="com.ibm.portal.struts.plugins.WpTilesPlugin">

Struts Action

The Struts action class is passed a HttpServletRequest object, so the application may not have a dependency on the Portal container. However, many applications use the PortletApiUtils to obtain the portlet request and interface directly with the portlet API. If this is the case then the application will have to replace the org.apache.jetspeed interfaces with the equivalent javax.portlet interfaces. The new interfaces are documented in the information center.

The following example illustrates the change in which the PortletApiUtils object is obtained:

  • Old: PortletApiUtils portletUtils = PortletApiUtils.getInstance();

  • New: PortletApiUtils portletUtils = PortletApiUtils.getUtilsInstance();

StrutsPortlet

The com.ibm.wps.portlets.struts.WpsStrutsPortlet class for the legacy container extended the PortletAdapter class. The Struts application using the Struts Portlet Framework may have been customized by extending the WpsStrutsPortlet class. If so, those changes should be applied for the Standard container. The com.ibm.portal.struts.portlet.StrutsPortlet class for the Standard container extends the standard container's GenericPortlet.

Request processor

The com.ibm.wps.portlets.struts.WpsRequestProcessor class for the legacy container may have been extended to customize the processing. The Request Processor class for the standard container is com.ibm.portal.struts.portlet.WpRequestProcessor.

If the legacy interfaces were used for the customizations, these changes should be converted to the Standard interfaces.


Parent topic:

IBM Portlet API