Portal, Express Beta Version 6.1 Operating systems: i5/OS, Linux,Windows

Creating your own portlet service

Writing a portlet service consists of four steps:

1. Defining the interface
2. Writing the service implementation
3. Making the service accessible for IBM portlets
4. Registering the service

The service provider interfaces can be used to write portlet services for IBM portlets as well as for Standard portlets. The IBM Portlet API is being deprecated for WebSphere Portal ExpressBeta but is still supported. No new functionality will be added and it is recommended that you use the Standard portlet API. For backward-compatibility, the service provider interfaces from the org.apache.jetspeed.portlet.service.spi packages are supported. For writing new portlets services, however, you should use only the service provider interfaces described in this text.

Defining the interface

package sample.portletservice;

import java.io.IOException;
import javax.portlet.RenderRequest;
import javax.portlet.RenderResponse;
import com.ibm.portal.portlet.service.PortletService;

public interface HelloService extends PortletService
{
    /** print a nice greeting */
    public void sayHello(RenderRequest request, RenderResponse response) 
           throws IOException;
}

Writing the service implementation

package sample.portletservice;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.prefs.Preferences;

import javax.portlet.RenderRequest;
import javax.portlet.RenderResponse;

import com.ibm.portal.portlet.service.spi.c;
 
public class HelloServiceImpl 
    implements HelloService, PortletServiceProvider {
    
    private String message;
        
    // called by the portal when the service is initialized        
    public void init(Preferences servicePreferences) {
        
        // read the message from the configuration, default is "Hello"
        message = servicePreferences.get("message", "Hello");
    }
        
    public void sayHello(RenderRequest request, RenderResponse response) 
                throws IOException {
        String user = request.getRemoteUser();
        if (user == null)
            // no user logged in
            user = "Stranger";
        
        PrintWriter out = response.getWriter();
        out.print(message);
        out.print(", ");
        out.print(user);            
    }

}

Making the service accessible for IBM portlets

package sample.portletservice;

import java.io.IOException;
import org.apache.jetspeed.portlet.PortletRequest;
import org.apache.jetspeed.portlet.PortletResponse;
import org.apache.jetspeed.portlet.service.PortletService;

public interface HelloServiceIBM extends PortletService {

    /** print a nice greeting */
    public void sayHello(PortletRequest request, PortletResponse response) throws IOException;

}

You can have a single implementation that is registered for both interfaces and implements both. If the service methods take arguments that are classes or interfaces from the portlet API, the method signatures are different for the two service interfaces. You can still use a common implementation for both interfaces by using the APIConverterFactory class of the com.ibm.portal.portlet.apiconvert package. This class includes methods that wrap objects from the IBM portlet API, such as the PortletRequest and _{PortletSession}, and implement the corresponding standard portlet API objects on the service side, so that you can re-use your service implementation for standard portlets.

package sample.portletservice;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.prefs.Preferences;

import javax.portlet.RenderRequest;
import javax.portlet.RenderResponse;

import org.apache.jetspeed.portlet.PortletRequest;
import org.apache.jetspeed.portlet.PortletResponse;

import com.ibm.portal.portlet.apiconvert.APIConverterFactory;
import com.ibm.portal.portlet.service.spi.PortletServiceProvider;
 
public class HelloServiceImpl2 
    implements HelloService, HelloServiceIBM, PortletServiceProvider {
    
    private String message;
        
    // called by the portal when the service is initialized        
    public void init(Preferences servicePreferences) {
        
        // read the message from the configuration, default is "Hello"
        message = servicePreferences.get("message", "Hello");
    }
        
    public void sayHello(RenderRequest request, RenderResponse response) 
                throws IOException {
        String user = request.getRemoteUser();
        if (user == null)
            // no user logged in
            user = "Stranger";
        
        PrintWriter out = response.getWriter();
        out.print(message);
        out.print(", ");
        out.print(user);            
    }
    
    public void sayHello(PortletRequest request, PortletResponse response) 
                throws IOException {
        sayHello (APIConverterFactory.getInstance().getRenderRequest(request),
            APIConverterFactory.getInstance().getRenderResponse(response));
    }

}

Registering the service

1. Put all service interface and implementation classes into a JAR file.
2. Place the JAR file in the portal_server_root/shared/app directory.
3. Register the new portlet service with the WP PortletServiceRegistryService resource environment provider in the WebSphere Application Server administration console.

   • Create an entry to register the implementation in the JNDI directory. The name for this entry is jndi.service_interface and the value is service_implementation. The fully qualified service interface name can then be used to lookup the service.
   • If you provide a service interface for IBM portlets, create an entry to register the implementation for this interface as well. The name for this entry is service_interface and the value is service_implementation. Services that are registered this way are not retrieved from JNDI, but from the PortletContext interface of the IBM portlet API.
   • Optional: Provide configuration parameters for the implementation. The name for this entry is service_implementation.parameter and the value is the desired parameter value.
4. Restart WebSphere Portal Express to activate the new settings.

	dumpNamespace -port bootstrap_port -root server -startAt portletservice

Using the application server's administrative console, you can find the bootstrap port of your portal server in the "End Points" section of the settings for the server "WebSphere_Portal".

Related information

• Portlet services
• Accessing portlet services
• Configuring portal behavior
• IBM WebSphere Developer Domain - Portal Zone
• Accessing remote systems