尝试使用队列外的 GET 消息设置 MQ（不是 JMS）

Question

我正在使用低级直接 IBM MQ 库将消息推送到队列中并检索它们。我试图设置应用程序以便消息可以进来，比如通过提取数据库的数据然后将记录推送到队列中，实际上相同的代码可以读取消息。我主要是想设置一个线程，一旦消息出现就会拉取消息。

此代码运行，第一个 PUT 工作，但第二个不工作并挂起。我不明白这里的流程吗

另外，如果我从下面的第二个“GET”周围获取代码，我是否可以编写一个线程，每 500 毫秒调用一次该例程，等待新消息进入。

        final int putOptions = MQC.MQPMO_NO_SYNCPOINT
                    | MQC.MQPMO_SYNC_RESPONSE;
            this.mqPMO = new MQPutMessageOptions();
            this.mqPMO.options = putOptions;
            // This code hangs !!!! (error here)
            mqueue.put(msg, this.mqPMO);

...

public void bootstap() {
        MQEnvironment.hostname = "localhost";
        MQEnvironment.port = 1414;
        MQEnvironment.channel = "DEV.ADMIN.SVRCONN";
        MQEnvironment.properties.put(MQConstants.APPNAME_PROPERTY, "my_application_name");
        MQEnvironment.enableTracing(5);

        MQQueueManager mqManager = null;
        MQQueue mqueue = null;
        try {
            // MQCNO_CLIENT_BINDING is not available for Java or .NET as they have their own mechanisms for choosing the bind type.
            final String qmName = "QM1";
            final String userId = "admin";
            final String Password = "passw0rd";
            final Hashtable h = new Hashtable();

            h.put(MQConstants.USER_ID_PROPERTY, userId);
            h.put(MQConstants.PASSWORD_PROPERTY, Password);
            h.put(MQConstants.USE_MQCSP_AUTHENTICATION_PROPERTY, true);
            mqManager = new MQQueueManager(qmName, h);
            //mqManager = new MQQueueManager(qmName, WMQConstants.WMQ_CM_BINDINGS);
            
            this.mqGMO = new MQGetMessageOptions();
            this.mqGMO.options = MQC.MQGMO_NO_SYNCPOINT |
                    MQC.MQGMO_WAIT |
                    MQC.MQGMO_CONVERT |
                    MQC.MQGMO_FAIL_IF_QUIESCING;
            this.mqGMO.matchOptions = MQC.MQMO_MATCH_CORREL_ID;
            this.mqGMO.waitInterval = MQC.MQWI_UNLIMITED;

            int openOptions =  MQC.MQOO_INPUT_SHARED |
                    MQC.MQOO_OUTPUT;
            mqueue = mqManager.accessQueue("DEV.QUEUE.1", openOptions);
            logger.info(">> Find connection handle queue manager - " + mqueue);

            {
                final MQMessage msg = new MQMessage();
                final String correlId = "0002";
                final String byteArry = this.hexStringToByteArray(correlId);

                logger.info(">>> correlId: " + correlId);
                logger.info(">>> byteArry: " + byteArry);

                msg.correlationId = byteArry.getBytes();
                msg.format = MQConstants.MQFMT_STRING;
                // ... and write some text in UTF8 format
                msg.writeUTF("{{ Hello, World }}}");

                // Use the default put message options...
                // Or: pmo.options = MQConstants.MQPMO_ASYNC_RESPONSE
                final int putOptions = MQC.MQPMO_NO_SYNCPOINT
                        | MQC.MQPMO_SYNC_RESPONSE;
                this.mqPMO = new MQPutMessageOptions();
                this.mqPMO.options = putOptions;

                // put the message //
                mqueue.put(msg, this.mqPMO);
                logger.info(" >>> Continue to get routine");
            }

            {
                // This code works !!! get the message
                MQMessage retrievedMessage = new MQMessage();
                retrievedMessage.correlationId = this.hexStringToByteArray("0001").getBytes();
                mqueue.get(retrievedMessage, this.mqGMO);

                // And prove we have the message by displaying the UTF message text
                String msgText = retrievedMessage.readUTF();
                logger.info("~~~~ The message is: " + msgText);
            }

            {
                final MQMessage msg = new MQMessage();
                final String correlId = "0001";
                final String byteArry = this.hexStringToByteArray(correlId);

                logger.info(">>> correlId: " + correlId);
                logger.info(">>> byteArry: " + byteArry);

                msg.correlationId = byteArry.getBytes();
                msg.format = MQConstants.MQFMT_STRING;
                // ... and write some text in UTF8 format
                msg.writeUTF("{{ Hello, World }}}");

                // Use the default put message options...
                // Or: pmo.options = MQConstants.MQPMO_ASYNC_RESPONSE
                final int putOptions = MQC.MQPMO_NO_SYNCPOINT
                        | MQC.MQPMO_SYNC_RESPONSE;
                this.mqPMO = new MQPutMessageOptions();
                this.mqPMO.options = putOptions;
                // This code hangs !!!! (error here)
                mqueue.put(msg, this.mqPMO);
            }


            mqueue.close();
            mqManager.disconnect();
        } catch(final Exception e) {
            logger.error("Error at MQ manager", e);
        }
    }

Answer 1

首先，不要使用 MQEnvironment 类，因为它不是线程安全的。您应该使用 Hashtable 获取 MQ 连接信息。

其次，所有的最终声明是什么？很奇怪。

您的代码没有任何意义。这是我看到你的代码在做什么：

• 设置MQ连接信息使用MQEnvironment类

• 在哈希表中设置用户 ID 和密码

• 连接到队列管理器

• 打开队列

• 将“correlId”设置为“0002”

  final String byteArry = this.hexStringToByteArray(correlId);

这行代码没有任何意义。方法名称与您的代码不匹配。十六进制字符串的格式应为“0002”的“30303032”并返回一个字节数组，即字节[]，但它返回一个字符串。所以，我不知道 hexStringToByteArray 方法在做什么。

另外，MQMD 结构的 MsgId、CorrelId 和 GroupId 字段的长度为 24 个字节。

• 以 UTF 格式写入消息数据。为什么？接收应用程序是否需要 UTF 格式？
• 将消息放入队列。
• 将接收消息的 CorrelId 设置为“0001”，但通过 hexStringToByteArray 方法转换为奇怪的表示形式。
• 从队列中获取一条等待间隔为无限的消息。由于队列上没有与该 CorrelId 匹配的消息，因此 MQ 客户端库将永远等待！！！！！！
• 创建另一个 MQMessage 并将 CorrelId 设置为“0001”，但通过 hexStringToByteArray 方法转换为奇怪的表示。
• 以 UTF 格式写入消息数据。为什么？接收应用程序是否需要 UTF 格式？
• 将消息放入队列。
• 关闭队列
• 与队列管理器断开连接

这是一个功能齐全的 Java/MQ 程序，它将 2 条消息放在具有唯一 CorrelId（即“0001”和“0002”）的队列中，然后检索 CorrelId 为“0002”的消息。

import java.io.IOException;
import java.text.DecimalFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Hashtable;

import com.ibm.mq.MQException;
import com.ibm.mq.MQGetMessageOptions;
import com.ibm.mq.MQMessage;
import com.ibm.mq.MQPutMessageOptions;
import com.ibm.mq.MQQueue;
import com.ibm.mq.MQQueueManager;
import com.ibm.mq.constants.CMQC;

/**
 * Program Name
 *  MQTest11B
 *
 * Description
 *  This java class will connect to a remote queue manager with the
 *  MQ setting stored in a HashTable, put 2 message on a queue with unique CorrelIds
 *  and then retrieve the message with a  CorrelId of "0002".
 *
 * Sample Command Line Parameters
 *  -m MQA1 -h 127.0.0.1 -p 1414 -c TEST.CHL -q TEST.Q1 -u UserID -x Password
 *
 * @author Roger Lacroix
 */
public class MQTest11B
{
   private static final SimpleDateFormat  LOGGER_TIMESTAMP = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss.SSS");

   private Hashtable<String,String> params;
   private Hashtable<String,Object> mqht;
   private String qMgrName;
   private String outputQName;

   /**
    * The constructor
    */
   public MQTest11B()
   {
      super();
      params = new Hashtable<String,String>();
      mqht = new Hashtable<String,Object>();
   }

   /**
    * Make sure the required parameters are present.
    * @return true/false
    */
   private boolean allParamsPresent()
   {
      boolean b = params.containsKey("-h") && params.containsKey("-p") &&
                  params.containsKey("-c") && params.containsKey("-m") &&
                  params.containsKey("-q") &&
                  params.containsKey("-u") && params.containsKey("-x");
      if (b)
      {
         try
         {
            Integer.parseInt((String) params.get("-p"));
         }
         catch (NumberFormatException e)
         {
            b = false;
         }
      }

      return b;
   }

   /**
    * Extract the command-line parameters and initialize the MQ HashTable.
    * @param args
    * @throws IllegalArgumentException
    */
   private void init(String[] args) throws IllegalArgumentException
   {
      int port = 1414;
      if (args.length > 0 && (args.length % 2) == 0)
      {
         for (int i = 0; i < args.length; i += 2)
         {
            params.put(args[i], args[i + 1]);
         }
      }
      else
      {
         throw new IllegalArgumentException();
      }

      if (allParamsPresent())
      {
         qMgrName = (String) params.get("-m");
         outputQName = (String) params.get("-q");

         try
         {
            port = Integer.parseInt((String) params.get("-p"));
         }
         catch (NumberFormatException e)
         {
            port = 1414;
         }
         
         mqht.put(CMQC.CHANNEL_PROPERTY, params.get("-c"));
         mqht.put(CMQC.HOST_NAME_PROPERTY, params.get("-h"));
         mqht.put(CMQC.PORT_PROPERTY, new Integer(port));
         mqht.put(CMQC.USER_ID_PROPERTY, params.get("-u"));
         mqht.put(CMQC.PASSWORD_PROPERTY, params.get("-x"));

         // I don't want to see MQ exceptions at the console.
         MQException.log = null;
      }
      else
      {
         throw new IllegalArgumentException();
      }
   }

   /**
    * Connect, open queue, write a message, close queue and disconnect.
    *
    */
   private void testSendAndReceive()
   {
      MQQueueManager qMgr = null;
      MQQueue queue = null;
      int openOptions = CMQC.MQOO_INPUT_SHARED | CMQC.MQOO_OUTPUT | CMQC.MQOO_FAIL_IF_QUIESCING;
      MQPutMessageOptions pmo = new MQPutMessageOptions();
      pmo.options = CMQC.MQPMO_NO_SYNCPOINT | CMQC.MQPMO_FAIL_IF_QUIESCING;
      MQGetMessageOptions gmo = new MQGetMessageOptions();
      gmo.options = CMQC.MQGMO_NO_SYNCPOINT | CMQC.MQGMO_WAIT | CMQC.MQGMO_CONVERT | CMQC.MQGMO_FAIL_IF_QUIESCING;
      gmo.matchOptions = CMQC.MQMO_MATCH_CORREL_ID;
      gmo.waitInterval = CMQC.MQWI_UNLIMITED;
      MQMessage sendmsg;
      String msgData;
      DecimalFormat df = new DecimalFormat("0000");

      try
      {
         qMgr = new MQQueueManager(qMgrName, mqht);
         logger("successfully connected to "+ qMgrName);

         queue = qMgr.accessQueue(outputQName, openOptions);
         logger("successfully opened "+ outputQName);
         
         /*
          * Code to send 2 messages with a specific CorrelId.  i.e. 0001 and 0002
          */
         for (int i=0; i < 2; i++)
         {
            // Define a simple MQ message, and write some text
            sendmsg = new MQMessage();
            sendmsg.format = CMQC.MQFMT_STRING;
            sendmsg.messageId = CMQC.MQMI_NONE;
            sendmsg.correlationId = df.format(i+1).getBytes();

            // Write message data
            msgData = "This is a test message from MQTest11B. CorrelID is "+new String(sendmsg.correlationId);
            sendmsg.writeString(msgData);

            // put the message on the queue
            queue.put(sendmsg, pmo);
            logger("Sent: Message Data>>>" + msgData);
         }
         
         /*
          * Code to receive a message with a specific CorrelId.  i.e. 0002
          */
         
         // Define a simple MQ message, and write some text
         MQMessage receiveMsg = new MQMessage();
         receiveMsg.messageId = CMQC.MQMI_NONE;
         receiveMsg.correlationId = "0002".getBytes();

         // get the message on the queue
         queue.get(receiveMsg, gmo);

         if (CMQC.MQFMT_STRING.equals(receiveMsg.format))
         {
            String msgStr = receiveMsg.readStringOfByteLength(receiveMsg.getMessageLength());
            logger("Received: Message Data>>>" + msgStr);
         }
         else
         {
            byte[] b = new byte[receiveMsg.getMessageLength()];
            receiveMsg.readFully(b);
            logger("Received: Message Data>>>" + new String(b));
         }
      }
      catch (MQException e)
      {
         logger("CC=" +e.completionCode + " : RC=" + e.reasonCode);
      }
      catch (IOException e)
      {
         logger("IOException:" +e.getLocalizedMessage());
      }
      finally
      {
         try
         {
            if (queue != null)
            {
               queue.close();
               logger("closed: "+ outputQName);
            }
         }
         catch (MQException e)
         {
            logger("CC=" +e.completionCode + " : RC=" + e.reasonCode);
         }
         try
         {
            if (qMgr != null)
            {
               qMgr.disconnect();
               logger("disconnected from "+ qMgrName);
            }
         }
         catch (MQException e)
         {
            logger("CC=" +e.completionCode + " : RC=" + e.reasonCode);
         }
      }
   }

   /**
    * A simple logger method
    * @param data
    */
   public static void logger(String data)
   {
      String className = Thread.currentThread().getStackTrace()[2].getClassName();

      // Remove the package info.
      if ( (className != null) && (className.lastIndexOf('.') != -1) )
         className = className.substring(className.lastIndexOf('.')+1);

      System.out.println(LOGGER_TIMESTAMP.format(new Date())+" "+className+": "+Thread.currentThread().getStackTrace()[2].getMethodName()+": "+data);
   }

   /**
    * main line
    * @param args
    */
   public static void main(String[] args)
   {
      MQTest11B write = new MQTest11B();

      try
      {
         write.init(args);
         write.testSendAndReceive();
      }
      catch (IllegalArgumentException e)
      {
         logger("Usage: java MQTest11B -m QueueManagerName -h host -p port -c channel -q QueueName -u UserID -x Password");
         System.exit(1);
      }

      System.exit(0);
   }
}

输出应该是这样的：

2021/07/02 14:01:59.316 MQTest11B: testSendAndReceive: successfully connected to MQA1
2021/07/02 14:01:59.332 MQTest11B: testSendAndReceive: successfully opened TEST.Q1
2021/07/02 14:01:59.332 MQTest11B: testSendAndReceive: Sent: Message Data>>>This is a test message from MQTest11B. CorrelID is 0001
2021/07/02 14:01:59.347 MQTest11B: testSendAndReceive: Sent: Message Data>>>This is a test message from MQTest11B. CorrelID is 0002
2021/07/02 14:01:59.347 MQTest11B: testSendAndReceive: Received: Message Data>>>This is a test message from MQTest11B. CorrelID is 0002
2021/07/02 14:01:59.347 MQTest11B: testSendAndReceive: closed: TEST.Q1
2021/07/02 14:01:59.347 MQTest11B: testSendAndReceive: disconnected from MQA1