Question

我将WebSphere MQ v7服务器和WebSphere MQ Client v7.5与amqmdnet.dll 7.5.0.0一起用作.NET库，以便通过WebSphere MQ进行通信。有时，当我尝试从队列中读取MQMessage时，我会MQException MQRC_RFH_FORMAT_ERROR原因。

var message = new MQMessage();
queue.Get(message);

此行为似乎取决于邮件的发件人及其内容。它通常不适用于使用float或double属性发送消息的不同平台上的系统。

Answer 1

这是IBM的amqmdnet.dll中的全球化错误。在客户端（strmqtrc.exe）上启用MQ跟踪后，我尝试再次收到消息，我在其中一个跟踪文件中找到了这个消息：

00001F21 11:48:00.351013   7104.1           :       Exception received
System.FormatException
Message: Input string was not in a correct format.
StackTrace:
   at System.Number.ParseSingle(String value, NumberStyles options, NumberFormatInfo numfmt)
   at System.Convert.ToSingle(String value)
   at IBM.WMQ.MQMarshalMessageForGet.GetValueAsObject(String dt, String propValue)
   at IBM.WMQ.MQMarshalMessageForGet.ProcessAllAvailableRFHs()
00001F22 11:48:00.351115   7104.1           :       We are not sucessful in parsing one of theRFH2Header.Raise the RFH_FORMAT exception and breakfurther processing in loop
00001F23 11:48:00.351825   7104.1           :       MQException CompCode: 2 Reason: 2421

使用.NET Reflector反复编译MQMarshalMessageForGet显示了这一点：

private object GetValueAsObject(string dt, string propValue)
{
    ...

    switch (dt)
    {
        ...

        case "r4":
            return Convert.ToSingle(propValue);

        case "r8":
            return Convert.ToDouble(propValue);

        ...
    }

    ...
}

在当前系统的文化中读取消息而不是在传输预期文化中（在所有平台上都应该相同）！简单的测试来重现这个问题：

[Test]
public void PutAndGetMessageWithFloatProperty() {
    using (MQQueue queue = _queueManager.AccessQueue(TestQueue, MQC.MQOO_OUTPUT | MQC.MQOO_INPUT_AS_Q_DEF))
    {
        Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US");

        MQMessage message = new MQMessage();
        message.SetFloatProperty("TEST_SINGLE", 14.879f);
        message.WriteString("some string");
        message.Format = MQC.MQFMT_STRING;

        queue.Put(message); // Writes property value as 14.879

        Thread.CurrentThread.CurrentCulture = new CultureInfo("cs-CZ");

        MQMessage readMessage = new MQMessage();
        queue.Get(readMessage); // Throws MQException because 14,879 is correct format

        queue.Close();
    }
}

解决方法

我正在使用这个简单的范围类：

public class CultureForThreadScope : IDisposable { private readonly CultureInfo oldCulture; public CultureForThreadScope(CultureInfo culture) { oldCulture = Thread.CurrentThread.CurrentCulture; Thread.CurrentThread.CurrentCulture = culture; } public void Dispose() { Thread.CurrentThread.CurrentCulture = oldCulture; } }

我正在将每个Get调用包装到范围内。

using (new CultureForThreadScope(CultureInfo.InvariantCulture)) { destination.Get(message, getOptions); }

在.NET中接收WebSphere MQ消息WMQ API有时会抛出MQRC_RFH_FORMAT_ERROR

1 个答案: