Example: Using KeyedDataQueue

///////////////////////////////////////////////////////////////////////////////
//
// Data Queue example.  This program uses the KeyedDataQueue class to put
// records on a data queue.
//
// The key is a number and the data is a Unicode string.  This program
// shows one way to convert on int into a byte array and how to convert
// a Java string into a byte array so it can be written to the queue.
//
// This is the producer side of the producer/consumer example.  It puts work
// items on the queue for the consumer to process.
//
// Command syntax:
//    DQKeyedProducer system
//
///////////////////////////////////////////////////////////////////////////////

import java.io.*;
import java.util.*;
import java.net.*;
import com.ibm.as400.access.*;

public class DQKeyedProducer extends Object
{

   // Create a reader to get input from the user.

   static BufferedReader inputStream = 
      new BufferedReader(new InputStreamReader(System.in),1);



   public static void main(String[] parameters)
   {

      System.out.println( " " );



      // if the system name was not specified, display help text and exit.

      if (parameters.length >= 1)
      {

         // The first parameter is the system that contains the data queue.

         String system = parameters[0];



         System.out.println("Priority is a numeric value. The value ranges are:");
         System.out.println("  0 -  49 = low priority");
         System.out.println(" 50 - 100 = medium priority");
         System.out.println("100 +     = high priority");
         System.out.println(" ");

         try
         {

             // Create an AS400 object for the server that has the data queue.

             AS400 as400 = new AS400(system);



             // Use CommandCall to create the library that contains the 
             // data queue.

             CommandCall crtlib = new CommandCall(as400);
             crtlib.run("CRTLIB JAVADEMO");



             // Create the data queue object.

             QSYSObjectPathName name = new QSYSObjectPathName("JAVADEMO", "PRODCON2", "DTAQ");

             KeyedDataQueue dq = new KeyedDataQueue(as400, name.getPath());



             // Create the data queue just in case this is the first time this
             // program has run.  The queue already exists exception is caught
             // and ignored.  The length of the key is four bytes, the length
             // of an entry is 96 bytes.

             try
             {
                dq.create(4, 96);
             }
             catch (Exception e) {};



             // Get the data from the user.

             System.out.print("Enter message: ");
             String message = inputStream.readLine();

             System.out.print("Enter priority: ");
             int priority = getInt();



             // While there is data to put on the queue.

             while (priority > 0)
             {

                // We want to write a java string as the entry to the queue.
                // Input the data queue is a byte array, however, so convert
                // the string to a byte array.

                byte [] byteData = message.getBytes("UnicodeBigUnmarked");



                // The key is a number.  Input to the data queue is a byte
                // array, however, so convert the int to a byte array;

                byte [] byteKey = new byte[4];
                byteKey[0] = (byte) (priority >>> 24);
                byteKey[1] = (byte) (priority >>> 16);
                byteKey[2] = (byte) (priority >>> 8);
                byteKey[3] = (byte) (priority);


                System.out.println("");
                System.out.println("Writing record to the server...");
                System.out.println("");



                // Write the record to the data queue.

                dq.write(byteKey, byteData);



                // Get the next value from the user.

                System.out.print("Enter message: ");
                message = inputStream.readLine();

                System.out.print("Enter priority: ");
                priority = getInt();
             }
         }
         catch (Exception e)
         {

            // If any of the above operations failed say the data queue
            // operation and output the exception.

            System.out.println("Data Queue operation failed");
            System.out.println(e);
         }
      }


      // Display help text when parameters are incorrect.

      else
      {
         System.out.println("");
         System.out.println("");
         System.out.println("");
         System.out.println("Parameters are not correct.  Command syntax is:");
         System.out.println("");
         System.out.println("  DQKeyedProducter system");
         System.out.println("");
         System.out.println("Where");
         System.out.println("");
         System.out.println("  system = server that has the data queue");
         System.out.println("");
         System.out.println("For example:");
         System.out.println("");
         System.out.println("  DQKeyedProducer mySystem");
         System.out.println("");
         System.out.println("");
      }

      System.exit(0);
   }




   // This is the subroutine that gets a character string from the user
   // and converts it into an int.

   static int getInt()
   {
      int i = 0;
      boolean Continue = true;

      while (Continue)
      {

         try
         {
            String s = inputStream.readLine();

            i = (new Integer(s)).intValue();
            Continue = false;
         }
         catch (Exception e)
         {
            System.out.println(e);
            System.out.print("Please enter a number ==>");
         }
      }

      return i;
   }
}