Example: Using DataQueue classes to read entries off a data queue
//////////////////////////////////////////////////////////////////////////////////
//
// Data Queue example. This program uses the Data Queue classes to read
// entries off a data queue on the AS/400. The entries were put on the
// queue with the DQProducer example program.
//
// This is the consumer side of the producer/consumer example. It reads
// entries off the queue and process them.
//
// Command syntax:
// DQConsumerExample system
//
//////////////////////////////////////////////////////////////////////////////////
//
// This source is an example of IBM Toolbox for Java DataQueue.
// IBM grants you a nonexclusive license to use this as an example
// from which you can generate similar function tailored to
// your own specific needs.
//
// This sample code is provided by IBM for illustrative purposes
// only. These examples have not been thoroughly tested under all
// conditions. IBM, therefore, cannot guarantee or imply
// reliability, serviceability, or function of these programs.
//
// All programs contained herein are provided to you "AS IS"
// without any warranties of any kind. The implied warranties of
// merchantablility and fitness for a particular purpose are
// expressly disclaimed.
//
// IBM Toolbox for Java
// (C) Copyright IBM Corp. 1997
// All rights reserved.
// US Government Users Restricted Rights -
// Use, duplication, or disclosure restricted
// by GSA ADP Schedule Contract with IBM Corp.
//
//////////////////////////////////////////////////////////////////////////////////
import java.io.*;
import java.util.*;
import java.net.*;
import com.ibm.as400.access.*;
public class DQConsumerExample extends Object
{
public static void main(String[] parameters)
{
System.out.println( " " );
// if a system name was not specified, display help text and exit.
if (parameters.length >= 1)
{
try
{
// The first parameter is the system that contains the data queue.
String system = parameters[0];
// Create an AS400 object for the AS/400 that has the data queue.
AS400 as400 = new AS400(system);
// Build a record format for the format of the data queue entry.
// This format matches the format in the DQProducer class. A
// record consists of:
// - a four byte number -- the customer number
// - a four byte number -- the part number
// - a 20 character string -- the part description
// - a four byte number -- the number of parts in this order
// First create the base data types.
BinaryFieldDescription customerNumber =
new BinaryFieldDescription(new AS400Bin4(), "CUSTOMER_NUMBER");
BinaryFieldDescription partNumber =
new BinaryFieldDescription(new AS400Bin4(), "PART_NUMBER");
CharacterFieldDescription partName =
new CharacterFieldDescription(new AS400Text(20, as400), "PART_NAME"
BinaryFieldDescription quantity =
new BinaryFieldDescription(new AS400Bin4(), "QUANTITY"
// Build a record format and fill it with the base data types.
RecordFormat dataFormat = new RecordFormat();
dataFormat.addFieldDescription(customerNumber);
dataFormat.addFieldDescription(partNumber);
dataFormat.addFieldDescription(partName);
dataFormat.addFieldDescription(quantity);
// Create the data queue object that represents the data queue on
// the AS/400.
DataQueue dq = new DataQueue(as400, "/QSYS.LIB/JAVADEMO.LIB/PRODCONS.DTAQ");
boolean Continue = true;
// Read the first entry off the queue. The timeout value is
// set to -1 so this program will wait forever for an entry.
System.out.println("*** Waiting for an entry for process ***");
DataQueueEntry DQData = dq.read(-1);
while (Continue)
{
// We just read an entry off the queue. Put the data into
// a record object so the program can access the fields of
// the data by name. The Record object will also convert
// the data from AS/400 format to Java format.
Record data = dataFormat.getNewRecord(DQData.getData());
// Get two values out of the record and display them.
Integer amountOrdered = (Integer) data.getField("QUANTITY");
String partOrdered = (String) data.getField("PART_NAME");
System.out.println("Need " + amountOrdered + " of " + partOrdered);
System.out.println(" ");
System.out.println("*** Waiting for an entry for process ***");
// Wait for the next entry.
DQData = dq.read(-1);
}
}
catch (Exception e)
{
// If any of the above operations failed say the data queue operation
// failed 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(" DQConsumerExample system");
System.out.println("");
System.out.println("Where");
System.out.println("");
System.out.println(" system = AS/400 that has the data queue");
System.out.println("");
System.out.println("For example:");
System.out.println("");
System.out.println(" DQConsumerExample mySystem");
System.out.println("");
System.out.println("");
}
System.exit(0);
}
}