java - 如何在不从队列中删除消息的情况下使用java读取MQ消息

Question

当我执行下面的代码时，它会在控制台上从 MQ 读取数据，然后从队列中删除所有数据。我不希望在从 MQ 读取时从队列中删除我的数据。我想让它参数化，也想把数据写入excel。谁能帮我解决这个问题。以下是我正在使用的代码。

public class MQReadJava
{
    private MQQueueManager _queueManager = null;
    public int port = 1416;
    public String hostname = "xyz";
    public String channel = "SYSTEM.ABC.123";
    public String qManager = "ABC.BAW";
    public String inputQName = "MYQUEUE";

    public MQReadJava()
    {
        super(); 
    }

    private void init(String[] args) throws IllegalArgumentException
    {
        // Set up MQ environment

        MQEnvironment.hostname = hostname;
        MQEnvironment.channel = channel;
        MQEnvironment.port = port;
    }

    public static void main(String[] args)throws IllegalArgumentException
    {
        MQReadJava readQ = new MQReadJava();
        try
        {
            readQ.init(args);
            readQ.selectQMgr();
            readQ.read();
        }

        catch (IllegalArgumentException e)
        {
            System.exit(1);
        }
        catch (MQException e)
        {
            System.out.println(e);
            System.exit(1);
        }
    }

    private void selectQMgr() throws MQException
    {
        _queueManager = new MQQueueManager(qManager);
    }

    private void read() throws MQException
    {
        int openOptions = MQC.MQOO_INQUIRE + MQC.MQOO_FAIL_IF_QUIESCING + MQC.MQOO_INPUT_SHARED;

        //int   openOptions = MQC.MQOO_INPUT_AS_Q_DEF | MQC.MQOO_FAIL_IF_QUIESCING;

        MQQueue queue = _queueManager.accessQueue( inputQName,
        openOptions,
        null, // default q manager
        null, // no dynamic q name
        null ); // no alternate user id

        System.out.println("MQRead is now connected.\n");
        int depth = queue.getCurrentDepth();
        System.out.println("Current depth: " + depth + "\n");

        if (depth == 0)
        {
            return;
        }

        MQGetMessageOptions getOptions = new MQGetMessageOptions();
        getOptions.options = MQC.MQGMO_NO_WAIT + MQC.MQGMO_FAIL_IF_QUIESCING + 
        MQC.MQGMO_CONVERT;

        while(true)
        {
            MQMessage message = new MQMessage();
            try
            {
                queue.get(message, getOptions);
                byte[] b = new byte[message.getMessageLength()];
                message.readFully(b);
                System.out.println(new String(b));
                message.clearMessage();
            }
            catch (IOException e)
            {
                System.out.println("IOException during GET: " + e.getMessage());
                break;
            }
            catch (MQException e)
            {
                if (e.completionCode == 2 && e.reasonCode == MQException.MQRC_NO_MSG_AVAILABLE) {
                    if (depth > 0)
                    {
                        System.out.println("All messages read.");
                    }
                }
                else
                {
                    System.out.println("GET Exception: " + e);
                }
                break;
            }
        }
        queue.close();
        _queueManager.disconnect();
    }
}

Answer 1

Below is my code that I am using.

:) 您下载了我的 MQRead 程序。如果您不希望它执行破坏性的 MQGET，那么您需要更新代码以进行浏览(请参阅 JoshMc 的评论)。你为什么不下载我的 MQBrowse 程序？最后，请开始阅读 MQ Knowledge Center因为它包含大量适用于 IBM MQ 初学者的信息。

---

更新:您不应使用 MQEnvironment 类，因为它不是线程安全的。将连接信息放在哈希表中。看这里的例子: Java program to connect WMQ with User Id instead of channel