c# - 重用 MQMessage 对象

Question

我有这个永远监听消息的测试代码。如果它得到一个它打印出来。我想要做的是避免必须在每个 get() 之前构造一个 MQMessage 对象。我如何为多次调用 get() 重用 MQMessage？

using System;
using IBM.WMQ;

namespace WMQ {
    class Program {
        static void Main(string[] args) {
            string QueueManagerName = "A1PATA00";
            string channelName = "ECACHE";
            string connectionName = "A1PATA00.WORLDSPAN.COM(1414)";
            var queueManager = new MQQueueManager(QueueManagerName, channelName, connectionName);
            MQQueue get = queueManager.AccessQueue("SPLASH.ECAC.2", MQC.MQOO_INPUT_AS_Q_DEF | MQC.MQGMO_FAIL_IF_QUIESCING);
            var gmo = new MQGetMessageOptions();
            gmo.Options = MQC.MQGMO_FAIL_IF_QUIESCING | MQC.MQGMO_WAIT;
            gmo.WaitInterval = 10000000;// wait time
            // var queueMessage = new MQMessage();  <--- i want to do this new once!
            while (true) {
                var queueMessage = new MQMessage(); // <-- only works if I do this every time i do a get
                get.Get(queueMessage, gmo);
                var strReturn = queueMessage.ReadString(queueMessage.MessageLength);
                Console.WriteLine(strReturn);
            }
        }
    }
}

Answer 1

1. 当我看到这样的问题时，我摇了摇头。你不了解 .NET VM(框架)中面向对象的概念，以及垃圾收集。
2. 另外，你为什么不编写纯 C# 代码？
3. 最后，在安全非常重要的世界中，您的代码确实不支持 SSL/TLS 和/或用户 ID 和密码身份验证。

(1) 请注意我在哪里定义 MQMessage 对象(非常重要)。

以下2个代码片段在内存使用或速度上基本上没有区别:

(一)

MQMessage msg = null;
while (true)
{
   msg = new MQMessage();
   get.Get(msg, gmo);
   Console.WriteLine(msg.ReadString(msg.MessageLength));
}

(乙)

MQMessage msg = new MQMessage();
while (true)
{
   get.Get(msg, gmo);
   Console.WriteLine(msg.ReadString(msg.MessageLength));
   msg.ClearMessage();
   msg.MessageId = MQC.MQMI_NONE;
   msg.CorrelationId = MQC.MQCI_NONE;
}

我更喜欢 (A)，因为它更清晰、更易于阅读。

(2) 当您使用“var”时，您是在迫使 .NET 框架猜测您在做什么。做纯面向对象的编程。即

MQMessage msg = new MQMessage();

(3) 在MQQueueManager中显式设置 channel 名和连接名不允许设置MQ安全信息。另外，不要使用 MQEnvironment 类，因为它不是线程安全的。最好将所有信息放在一个 Hashtable 中并将 Hashtable 传递给 MQQueueManager 类。下面是一个使用哈希表获取 MQ 连接信息的 MQ .NET 托管模式示例:

using System;
using System.Collections;
using System.Collections.Generic;
using System.Text;
using IBM.WMQ;

namespace MQTest02
{
   class MQTest02
   {
      private Hashtable inParms = null;
      private Hashtable qMgrProp = null;
      private System.String qManager;
      private System.String outputQName;

      /*
      * The constructor
      */
      public MQTest02()
         : base()
      {
      }

      /// <summary> Make sure the required parameters are present.</summary>
      /// <returns> true/false
      /// </returns>
      private bool allParamsPresent()
      {
         bool b = inParms.ContainsKey("-h") && inParms.ContainsKey("-p") &&
                  inParms.ContainsKey("-c") && inParms.ContainsKey("-m") &&
                  inParms.ContainsKey("-q");
         if (b)
         {
            try
            {
               System.Int32.Parse((System.String)inParms["-p"]);
            }
            catch (System.FormatException e)
            {
               b = false;
            }
         }

         return b;
      }

      /// <summary> Extract the command-line parameters and initialize the MQ variables.</summary>
      /// <param name="args">
      /// </param>
      /// <throws>  IllegalArgumentException </throws>
      private void init(System.String[] args)
      {
         inParms = Hashtable.Synchronized(new Hashtable());
         if (args.Length > 0 && (args.Length % 2) == 0)
         {
            for (int i = 0; i < args.Length; i += 2)
            {
               inParms[args[i]] = args[i + 1];
            }
         }
         else
         {
            throw new System.ArgumentException();
         }

         if (allParamsPresent())
         {
            qManager = ((System.String)inParms["-m"]);
            outputQName = ((System.String)inParms["-q"]);

            qMgrProp = new Hashtable();
            qMgrProp.Add(MQC.TRANSPORT_PROPERTY, MQC.TRANSPORT_MQSERIES_MANAGED);

            qMgrProp.Add(MQC.HOST_NAME_PROPERTY, ((System.String)inParms["-h"]));
            qMgrProp.Add(MQC.CHANNEL_PROPERTY, ((System.String)inParms["-c"]));

            try
            {
               qMgrProp.Add(MQC.PORT_PROPERTY, System.Int32.Parse((System.String)inParms["-p"]));
            }
            catch (System.FormatException e)
            {
               qMgrProp.Add(MQC.PORT_PROPERTY, 1414);
            }

            if (inParms.ContainsKey("-u"))
               qMgrProp.Add(MQC.USER_ID_PROPERTY, ((System.String)inParms["-u"]));

            if (inParms.ContainsKey("-x"))
               qMgrProp.Add(MQC.PASSWORD_PROPERTY, ((System.String)inParms["-x"]));

            if (inParms.ContainsKey("-s"))
               qMgrProp.Add(MQC.SECURITY_EXIT_PROPERTY, ((System.String)inParms["-s"]));

            System.Console.Out.WriteLine("MQTest02:");
            Console.WriteLine("  QMgrName ='{0}'", qManager);
            Console.WriteLine("  Output QName ='{0}'", outputQName);

            System.Console.Out.WriteLine("QMgr Property values:");
            foreach (DictionaryEntry de in qMgrProp)
            {
               Console.WriteLine("  {0} = '{1}'", de.Key, de.Value);
            }
         }
         else
         {
            throw new System.ArgumentException();
         }
      }

      /// <summary> Connect, open queue, read a message, close queue and disconnect.
      ///
      /// </summary>
      /// <throws>  MQException </throws>
      private void testReceive()
      {
         MQQueueManager qMgr = null;
         MQQueue queue = null;
         int openOptions = MQC.MQOO_INPUT_AS_Q_DEF + MQC.MQOO_FAIL_IF_QUIESCING;
         MQGetMessageOptions gmo = new MQGetMessageOptions();
         MQMessage receiveMsg = null;

         try
         {
            qMgr = new MQQueueManager(qManager, qMgrProp);
            System.Console.Out.WriteLine("MQTest02 successfully connected to " + qManager);

            queue = qMgr.AccessQueue(outputQName, openOptions, null, null, null); // no alternate user id
            System.Console.Out.WriteLine("MQTest02 successfully opened " + outputQName);

            receiveMsg = new MQMessage();

            queue.Get(receiveMsg, gmo);
            System.Console.Out.WriteLine("Message Data>>>" + receiveMsg.ReadString(receiveMsg.MessageLength));
         }
         catch (MQException mqex)
         {
            System.Console.Out.WriteLine("MQTest02 cc=" + mqex.CompletionCode + " : rc=" + mqex.ReasonCode);
         }
         catch (System.IO.IOException ioex)
         {
            System.Console.Out.WriteLine("MQTest02 ioex=" + ioex);
         }
         finally
         {
            try
            {
               queue.Close();
               System.Console.Out.WriteLine("MQTest02 closed: " + outputQName);
            }
            catch (MQException mqex)
            {
               System.Console.Out.WriteLine("MQTest02 cc=" + mqex.CompletionCode + " : rc=" + mqex.ReasonCode);
            }
            try
            {
               qMgr.Disconnect();
               System.Console.Out.WriteLine("MQTest02 disconnected from " + qManager);
            }
            catch (MQException mqex)
            {
               System.Console.Out.WriteLine("MQTest02 cc=" + mqex.CompletionCode + " : rc=" + mqex.ReasonCode);
            }
         }
      }

      /// <summary> main line</summary>
      /// <param name="args">
      /// </param>
      //        [STAThread]
      public static void Main(System.String[] args)
      {
         MQTest02 mqt = new MQTest02();

         try
         {
            mqt.init(args);
            mqt.testReceive();
         }
         catch (System.ArgumentException e)
         {
            System.Console.Out.WriteLine("Usage: MQTest02 -h host -p port -c channel -m QueueManagerName -q QueueName [-u userID] [-x passwd] [-s securityExit]");
            System.Environment.Exit(1);
         }
         catch (MQException e)
         {
            System.Console.Out.WriteLine(e);
            System.Environment.Exit(1);
         }

         System.Environment.Exit(0);
      }
   }
}

要使用您的信息运行 MQTest02，它将是:

MQTest02.exe -h A1PATA00.WORLDSPAN.COM -p 1414 -m A1PATA00 -c ECACHE -q SPLASH.ECAC.2