content: /*
   *                         Vortex OpenSplice
   *
   *   This software and documentation are Copyright 2006 to TO_YEAR ADLINK
   *   Technology Limited, its affiliated companies and licensors. All rights
   *   reserved.
   *
   *   Licensed under the Apache License, Version 2.0 (the "License");
   *   you may not use this file except in compliance with the License.
   *   You may obtain a copy of the License at
   *
   *       http://www.apache.org/licenses/LICENSE-2.0
   *
   *   Unless required by applicable law or agreed to in writing, software
   *   distributed under the License is distributed on an "AS IS" BASIS,
   *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *   See the License for the specific language governing permissions and
   *   limitations under the License.
   *
   */
  
  /************************************************************************
   * LOGICAL_NAME:    DataReaderListenerImpl.java
   * FUNCTION:        OpenSplice Tutorial example code.
   * MODULE:          Tutorial for the Java programming language.
   * DATE             june 2007.
   ************************************************************************
   *
   * This file contains the implementation for a DataReader listener, that
   * simulates MultiTopic behavior by writing a NamedMessage sample (which
   * contains the merged information from both the ChatMessage and NameService
   * topics) for each incoming ChatMessage.
   *
   ***/
  
  package chatroom;
  
  import DDS.*;
  import Chat.*;
  
  public class DataReaderListenerImpl extends org.opensplice.dds.dcps.ListenerBase
                                      implements DataReaderListener {
  
      /***
       * Attributes
       ***/
      /* Caching variables */
      private int                   previous      = 0x80000000;
      private String                userName;
      private ChatMessageSeqHolder  msgSeq        = new ChatMessageSeqHolder();
      private NameServiceSeqHolder  nameSeq       = new NameServiceSeqHolder();
      private SampleInfoSeqHolder   infoSeq1      = new SampleInfoSeqHolder();
      private SampleInfoSeqHolder   infoSeq2      = new SampleInfoSeqHolder();
      private NamedMessage          joinedSample  = new NamedMessage();
  
  
      /* Type-specific DDS entities */
      public ChatMessageDataReader        chatMessageDR;
      public NameServiceDataReader        nameServiceDR;
      public NamedMessageDataWriter       namedMessageDW;
  
      /* Query related stuff */
      public QueryCondition               nameFinder;
      public String[]                     nameFinderParams;
  
      /***
       * Operations
       ***/
      public void on_requested_deadline_missed(
              DataReader the_reader,
              RequestedDeadlineMissedStatus status) { }
  
      public void on_requested_incompatible_qos(
              DataReader the_reader,
              RequestedIncompatibleQosStatus status) { }
  
      public void on_sample_rejected(
          DataReader the_reader, SampleRejectedStatus status) { }
  
      public void on_liveliness_changed(
          DataReader the_reader, LivelinessChangedStatus status) { }
  
      public void on_data_available(DataReader the_reader) {
          int count = 0;
          previous = 0x80000000;
  
          /* Take all messages. */
          int status = chatMessageDR.take(
              msgSeq,
              infoSeq1,
              LENGTH_UNLIMITED.value,
              ANY_SAMPLE_STATE.value,
              ANY_VIEW_STATE.value,
              ANY_INSTANCE_STATE.value);
          ErrorHandler.checkStatus(
              status, "Chat.ChatMessageDataReader.take");
  
          /* For each message, extract the key-field and find
             the corresponding name. */
          for (int i = 0; i < msgSeq.value.length; i++)
          {
              if (infoSeq1.value[i].valid_data)
              {
                  /* Find the corresponding named message. */
                  if (msgSeq.value[i].userID != previous)
                  {
                      previous = msgSeq.value[i].userID;
                      nameFinderParams[0] = Integer.toString(previous);
                      status = nameFinder.set_query_parameters(nameFinderParams);
                      ErrorHandler.checkStatus(
                          status, "DDS.QueryCondition.set_query_parameters");
  
                      /* To ensure the identifier for the sender is presented with the message
                       * content, it may be necessary to try reading again if the NameService
                       * sample is not initially available.  This is because the arrival order
                       * of samples representing different topics cannot be guaranteeed.
                       */
                      status = RETCODE_NO_DATA.value;
                      while (status == RETCODE_NO_DATA.value && count < 10)
                      {
                          status = nameServiceDR.read_w_condition(
                              nameSeq,
                              infoSeq2,
                              LENGTH_UNLIMITED.value,
                              nameFinder);
                          ErrorHandler.checkStatus(
                              status, "Chat.NameServiceDataReader.read_w_condition");
  
                          /* Extract Name (there should only be one result). */
                          if (status == RETCODE_NO_DATA.value)
                          {
                              userName = new String(
                                 "Name not found!! id = " + previous);
  
                              /* Sleep for some amount of time, as not to consume too much CPU cycles. */
                              try
                              {
                                  Thread.sleep (100);
                              }
                              catch (InterruptedException e)
                              {
                                  e.printStackTrace();
                              }
  
                              count++;
                          }
                          else
                          {
                              userName = nameSeq.value[0].name;
                              /* Release the name sample again. */
                              status = nameServiceDR.return_loan(nameSeq, infoSeq2);
                              ErrorHandler.checkStatus(
                                  status, "Chat.NameServiceDataReader.return_loan");
                          }
                      }
                  }
                  /* Write merged Topic with userName instead of userID. */
                  joinedSample.userName = userName;
                  joinedSample.userID = msgSeq.value[i].userID;
                  joinedSample.index = msgSeq.value[i].index;
                  joinedSample.content = msgSeq.value[i].content;
                  status = namedMessageDW.write(joinedSample, HANDLE_NIL.value);
                  ErrorHandler.checkStatus(
                      status, "Chat.NamedMessageDataWriter.write");
              }
          }
          status = chatMessageDR.return_loan(msgSeq, infoSeq1);
          ErrorHandler.checkStatus(
              status, "Chat.ChatMessageDataReader.return_loan");
  
      }
  
      public void on_subscription_matched(
          DataReader the_reader, SubscriptionMatchedStatus status) { }
  
      public void on_sample_lost(
          DataReader the_reader, SampleLostStatus status) { }
  }
  