對 ActiveMQ .NET 1.1.0 元件接受中文資訊亂碼的修復

iDotNetSpace發表於2009-10-13

最近在使用 Apache ActiveMQ 訊息佇列做一些工作，在使用的時候，發現傳送訊息的內容是中文時，獲得訊息時，獲得的是亂碼。

傳送和接收我使用的是 ActiveMQ .NET 1.1.0 元件。

分析原因進去後，發現是這個開源元件的 Apache.NMS.ActiveMQ 元件的 \Apache.NMS.ActiveMQ-1.1.0-src\src\main\csharp\Transport\Stomp\StompWireFormat.cs 檔案對應的 StompWireFormat 類的 public Object Unmarshal(BinaryReader dis) 方法中有錯誤。

錯誤在該檔案的 166 行

之前的錯誤程式碼如下：

public Object Unmarshal(BinaryReader dis)
{
	string command;
	do {
		command = ReadLine(dis);
	}
	while (command == "");
	
	Tracer.Debug("<<<< command: " + command);
	
	IDictionary headers = new Hashtable();
	string line;
	while ((line = ReadLine(dis)) != "")
	{
		int idx = line.IndexOf(':');
		if (idx > 0)
		{
			string key = line.Substring(0, idx);
			string value = line.Substring(idx + 1);
			headers[key] = value;
			
			Tracer.Debug("<<<< header: " + key + " = " + value);
		}
		else
		{
			// lets ignore this bad header!
		}
	}
	byte[] content = null;
	string length = ToString(headers["content-length"]);
	if (length != null)
	{
		int size = Int32.Parse(length);
		content = dis.ReadBytes(size);
		// Read the terminating NULL byte for this frame.
		int nullByte = dis.Read();
		if(nullByte != 0)
		{
			Tracer.Debug("<<<< error reading frame. null byte.");
		}
	}
	else
	{
		MemoryStream ms = new MemoryStream();
		int nextChar;
		while((nextChar = dis.Read()) != 0)
		{
		    if( nextChar < 0 )
		    {
		        // EOF ??
		        break;
		    }
			ms.WriteByte((byte)nextChar);
		}
                content = ms.ToArray();
	}
	Object answer = CreateCommand(command, headers, content);
	Tracer.Debug("<<<< received: " + answer);
	return answer;
}

internal String ReadLine(BinaryReader dis)
{
    MemoryStream ms = new MemoryStream();
    while (true)
    {
        int nextChar = dis.Read();
        if (nextChar < 0)
        {
            throw new IOException("Peer closed the stream.");
        }
        if( nextChar == 10 )
        {
            break;
        }
        ms.WriteByte((byte)nextChar);
    }
    byte[] data = ms.ToArray();
    return encoding.GetString(data, 0, data.Length);
}

這個原始碼檔案可以在下面地址看到：

https://svn.apache.org/repos/asf/activemq/activemq-dotnet/Apache.NMS.ActiveMQ/tags/1.1.0/src/main/csharp/Transport/Stomp/StompWireFormat.cs

正確的程式碼如下：

internal string ReadLine(NetworkStream ns)
{
    MemoryStream ms = new MemoryStream();
    while (true)
    {
        int nextChar = ns.ReadByte();
        if (nextChar < 0)
        {
            throw new IOException("Peer closed the stream.");
        }
        if (nextChar == 10)
        {
            break;
        }
        ms.WriteByte((byte)nextChar);
    }
    byte[] data = ms.ToArray();
    return encoding.GetString(data, 0, data.Length);
}
public Object Unmarshal(BinaryReader dis)
{
    NetworkStream ns = dis.BaseStream as NetworkStream;
    if (ns == null) return null;
    if (!ns.CanRead) return null;

    // 讀取 command 資訊
    string command;
    do
    {
        command = ReadLine(ns);
    }
    while (command == "");

    Tracer.Debug("<<<< command: " + command);

    // 讀取 header 資訊
    IDictionary headers = new Hashtable();
    string line;
    while ((line = ReadLine(ns)) != "")
    {
        int idx = line.IndexOf(':');
        if (idx > 0)
        {
            string key = line.Substring(0, idx);
            string value = line.Substring(idx + 1);
            headers[key] = value;

            Tracer.Debug("<<<< header: " + key + " = " + value);
        }
        else
        {
            // lets ignore this bad header!
        }
    }

    // 讀取訊息內容
    MemoryStream ms = new MemoryStream();
    do
    {
        int t = ns.ReadByte();
        if (t <= 0) break;
        ms.WriteByte((byte)t);
    }
    while (ns.DataAvailable);

    byte[] content = ms.ToArray();
                       
    Object answer = CreateCommand(command, headers, content);
    Tracer.Debug("<<<< received: " + answer);
    return answer;
}