enqueueprdhelper.java

ORACLE AQ sample 演示的如何出列

package oracle.otnsamples.AQ.Helper;
/**
 * @author  Anupama
 * @version 1.0
 *
 * Development Environment        :  Oracle9i JDeveloper
 * Name of the Application        :  EnqueuePrdHelper.java
 * Creation/Modification History  :
 *
 *    Anupama      29-Jan-2002      Created
 *
 */

// Oracle JMS imports
import oracle.jms.AdtMessage;
import oracle.jms.AQjmsFactory;
import oracle.jms.AQjmsConstants;
import oracle.jms.AQjmsSession;

// JMS imports
import javax.jms.DeliveryMode;
import javax.jms.TopicConnection;
import javax.jms.Session;
import javax.jms.Topic;
import javax.jms.TopicConnectionFactory;
import javax.jms.JMSException;
import javax.jms.TopicSession;
import javax.jms.TopicPublisher;

// SQL imports
import java.sql.SQLException;

// Util imports
import java.util.Hashtable;

/**
 * This class is used to enqueue the product details sent to it by creating
 * a connection with the database using JMS classes and then publishing
 * the message.  Before running this class make sure that these are done.
 * 1. Queue table is created in the database.
 * 2. At least one subscriber is created for the queue.
 * 3. The queue is started.
 */
public class EnqueuePrdHelper{

 /**
  * This method is called after a product is successfully added or
  * updated in the database. The main tasks performed by this
  * method is call the methods to create a session, send the session
  * thus retrieved to get the topic and use this topic to enqueue the
  * message.
  *
  * @param p_addedProductInfo Details of the product to be added to queue
  * @param p_user Type of the user
  * @param p_action It tells if the product is being added or updated
  * @exception Exception Incase of some error or unreported Exception.
  */
 public static void addPrdToQueue(Product p_addedProductInfo, String p_user,
                                            String p_action) throws Exception {
    // Get the Database userDetails using the Connection Helper.
    Hashtable dbUserDetails = ConnectionHelper.getDBUserDetails(p_user);

    // Connects to the database and creates Topic Session
    Session session = createJmsSession(dbUserDetails);

    // Gets the topic for the queue present in database.
    Topic topic = getProductsTopic(session, dbUserDetails);

    // Publishes the product after storing the details of the product in the
    // object of ProductDat.
    publishManufacturerPrd(session, topic, p_addedProductInfo, p_user, p_action);
  }

  /**
   * This method is called after the products selected are successfully
   * deleted from the database. The main tasks performed by this
   * method is call the methods to create a session, send the session
   * thus retrieved to get the topic and use this topic to enqueue all
   * the
   * products message.
   *
   * @param p_prdsDeletedArr Details of the product to be enqueued which are
   *     deleted from the database
   * @param p_user Type of the user
   * @param p_action It tells if the product is being added or updated or
   *      deleted
   * @exception Exception Incase of some error or unreported Exception.
   */
  public static void addPrdToQueue(Product[] p_prdsDeletedArr, String p_user,
                                            String p_action) throws Exception {
    // Get the Database userDetails using the Connection Helper.
    Hashtable dbUserDetails = ConnectionHelper.getDBUserDetails(p_user);

    // Connects to the database and creates Topic Session
    Session session = createJmsSession(dbUserDetails);

    // Gets the topic for the queue present in database.
    Topic topic = getProductsTopic(session, dbUserDetails);

    // Publishes the product after storing the details of the product in the
    // object of ProductDat.
    publishManufacturerPrd(session, topic, p_prdsDeletedArr, p_user, p_action);
  }

   /**
    * This method helps to create a JMSSession object.
    * The JMSSession object is used to create a session
    * object through which the publisher and subscribers
    * can send and receive messages using queue.
    * Depending on the type of user, the parameters of the
    * database are retrieved.
    *
    * @exception Exception Incase of some error or unreported Exception.
    * @param dbUserDetails Contains the database user to which the
    *     manufacturer should connect
    * @return Returns the Session created through which messages can be
    *     published.
    */
   public static Session createJmsSession(Hashtable p_dbUserDetails)
                                                      throws Exception{
    try{
       TopicConnectionFactory  topicConnFactory;
       TopicConnection         topicConnection;
       TopicSession            topicSession = null;
       String hostName  = (String)p_dbUserDetails.get("HostName");
       String SID       = (String)p_dbUserDetails.get("SID");
       int portNo       = Integer.parseInt(((Integer)p_dbUserDetails.
                                              get("PortNo")).toString());
       String driver    = (String)p_dbUserDetails.get("Driver");
       String userName  = (String)p_dbUserDetails.get("UserName");
       String password  = (String)p_dbUserDetails.get("Password");

       // Connection Factory is required to tell to which database we are
       // about to connect, its host number and other details.
       // A Topic Connection Factory is required if there are multiple subscriber
       // to the queue. The static method getTopicConnectionFactory present
       // in AQjmsFactory retrieves Connection Factory.
       // The syntax of the method is
       // getTopicConnectionFactory(String hostname,String oracle_sid,
       //                               int port,String driver)
       topicConnFactory=AQjmsFactory.getTopicConnectionFactory(hostName, SID,
                                                          portNo, driver);

       // A Topic Connection must be created to the database where the queue
       // resides. It is retrieved using the method createTopicConnection
       // present in Topic Connection Factory.
       // The syntax of this method used here is
       // createTopicConnection(String userName,String  password)
       topicConnection = topicConnFactory.createTopicConnection(userName,password);

       // A topic session is required for publishing the messages. Destination
       // objects are created from a Session object using domain
       // specific session methods.
       // The syntax of this method is
       // createTopicSession(boolean newSession, int properties)
       // where newSession tells if a new JMS Session need to be created
       // properties tells the properties of the Session like
       // if acknowledgement is required or not, etc
       try{
         topicSession =  topicConnection.createTopicSession(true, 0);
       }catch(Exception e){
         e.printStackTrace();
       }

       // Start the connection to publish messages
       topicConnection.start();

       return topicSession;
    }catch(JMSException p_JmsExp){
       p_JmsExp.printStackTrace();
       throw new Exception("AQ-1013");
    }
  }

  /**
   * This method helps to retrieve the topic for the queue table
   * specified in the respective database. Topic is used to publish
   * messages to multi consumer queue.
   *
   * @param jmsSession Session object in which this topic is created