10 Understanding the Topic Service

The Topic Service interface represents the methods that operate on Oracle Discussions Topics. The interface provides the following operations:

• Creating a topic

• Listing of messages under a topic

• Locking or unlocking a topic

• Retrieving a topic

• Moving a topic from one forum to another

• Editing the contents of a topic

• Deleting a topic

It also provides bulk operations to create or delete multiple topics in one invocation. This chapter addresses the task of Creating a Topic.

Creating a Topic

The following is an example for creating a topic from the byte array:

Example 10-1 Creating a Topic from the Byte Array

import java.util.Date;
import java.io.*;
import java.util.*;
import javax.mail.*;
import javax.mail.internet.*;

import org.apache.axis.transport.http.HTTPConstants;import oracle.discussions.ws.exceptions.TdWSException;import oracle.discussions.ws.beans.*;import oracle.discussions.ws.AuthenticationServiceServiceLocator;import oracle.discussions.ws.AuthenticationServiceSoapBindingStub;import oracle.discussions.ws.AuthenticationService;import oracle.discussions.ws.TopicServiceSoapBindingStub;import oracle.discussions.ws.TopicServiceServiceLocator;import oracle.discussions.ws.TopicService;

public class WSClient{  private static AuthenticationService as = null;    public static String getCookie() throws Exception  {      //STEP - 0: User Login            //Create the service locator for authentication service. The locator
            //contains information about the web Services endpoint             AuthenticationServiceServiceLocator assl = new
                            AuthenticationServiceServiceLocator();            //Get the handle to the actual webservices interface.             as = assl.getAuthenticationService();            //Indicate to the server that the client is interested in maintaining
            //session.            //HTTP is stateless and the user state is maintained in the session.            //Unless the user is willing to participate in a session, user state
            //cannot be preserved.             ((AuthenticationServiceSoapBindingStub)as).setMaintainSession(true);            //Invoke the actual login webservices call.              as.login("td_superuser","welcome1");            //Retrieve the cookie. The cookie is set on successful authentication.
             String cookie = (String)((AuthenticationServiceSoapBindingStub)as)
                                     ._getCall().getMessageContext()
                                   .getProperty(HTTPConstants.HEADER_COOKIE);             System.out.println("Cookie : " + cookie);             return cookie;         }

        public static void main(String args[])         {          try          {              //STEP - 0: User Login              String cookie = getCookie();                 //STEP - 1: Locate the Web Services end point.             //The Web Services locator contains the Web Services end point
             //address             //Hence instantiate the service locator.              TopicServiceServiceLocator tssl = new TopicServiceServiceLocator();             //Get a handle to the actual web service.              TopicService ts = tssl.getTopicService();                   //Indicate to the server that the user is willing to participate in
             //the session.             //Since HTTP is stateless, all the client data is maintained in the
             //session.              ((TopicServiceSoapBindingStub)ts).setMaintainSession(true);             //Set the cookie retrieved in the call to login webservice.             //The cookie asserts user's identity to the server.              ((javax.xml.rpc.Stub)ts)._setProperty(HTTPConstants.HEADER_
                                                       COOKIE,cookie);             //Invoke the actual web services call.              byte[] bytes = null;
             //Create a MIME Compatible byte array              if(bytes != null)              {
               //The ID needs to be changed accordingly
                ForumMessage msg = ts.createTopicFromByte(15524,bytes);                if(msg != null)                {                 System.out.println("Subject :" + msg.getSubject());                 System.out.println("Web ui url :" + msg.getWebUIUrl());          System.out.println("Subject :" + msg.getSubject());          System.out.println("Plain Text :" + msg.getBodyPlainText());          String[] frmAdd = msg.getFromAddresses();          if(frmAdd != null)
          {              for(int j = 0 ; j < frmAdd.length ; j++)                  System.out.println("From Address :" + frmAdd[j]);          }          System.out.println("Level :" + msg.getLevel());          System.out.println("No of replies :" + msg.getNumberOfReplies());          System.out.println("Oracle Msg Id :" + msg.getMessageId());          System.out.println("is new since session :" + msg.isNewSinceSession());          System.out.println("is new since last visit :" +
                                       msg.isNewSinceLastVisit());          System.out.println("is new " + msg.isNewMessage());          System.out.println("Has Attachments :" + msg.isHasAttachments());          System.out.println("X Priority :" + msg.getXPriority());          System.out.println("Sent dat :" + msg.getSentDate());          System.out.println("Size :" + msg.getSize());          System.out.println("Subject :" + msg.getSubject());        }                }
      //STEP - 2: User Logout       logout();     }     catch(TdWSException ex)     {         System.out.println("Error Code :" + ex.getErrorCode());         System.out.println("Error Message :" + ex.getErrorMessage());         String[] trace = ex.getServerStackTrace();         if(trace != null)         {             for(int i = 0 ; i < trace.length ; i++)                 System.out.println("trace[" + i + "]" + trace[i]);         }     }     catch(Exception ex)     {         System.out.println("Never went into tdex :" + ex.getMessage());           ex.printStackTrace();     }   }
   public static void logout() throws Exception   {       System.out.println("User logout.");       //Once all the webservices operations are done, invoke logout        //operation.       //On logout, user state is destroyed and the cookie is invalidated.
       as.logout();       System.out.println("Done");    }}

The createTopicFromByte() creates a topic from the specified byte array.

The byte[] array should be MIME compatible. It is useful in creating topics with attachments. The entire message, along with all the headers and attachments is converted into a byte[]. The same byte[] can be used in creating a topic. This method accepts two parameters:

• lForumId is the ID representing a forum, in which topic is to be created.

• msg is the byte representing the topic to be created.

The method returns ForumMessage which is a bean that represents the newly created topic.

The sample output for Example 10-1 is as follows:

Cookie : JSESSIONID=8c57046a22b87bc7c77f14844facb3d6e912391d9f5dSubject :Topic-1Web ui url :http://stacx01:8888/discussions/app/mainAction.do?fid=15524&tid=281488&mid=281488#281488Subject :Topic-1Plain Text :Topic-1From Address :Admin <[e-mail]>Level :0No of replies :0Oracle Msg Id :281488is new since session :trueis new since last visit :trueis new trueHas Attachments :falseX Priority :1Sent date : Sun Feb 26 19:54:18 PST 2006Size :405Subject :Topic-1User logout.Done