ActiveMQ使用(五):在JavaScript中发送的MQTT消息在C#中变为字节数组

1. 问题描述

** C#中的代码: **

internal class Program
    {
        static void Main(string[] args)
        {
            ConnectionFactory factory = new ConnectionFactory("tcp://localhost:61616");
            IConnection connection = factory.CreateConnection();
            connection.Start();
            ISession session = connection.CreateSession();
            IMessageConsumer consumer = session.CreateConsumer(new Apache.NMS.ActiveMQ.Commands.ActiveMQTopic("test_producer"));
            consumer.Listener += new MessageListener(consumerListener);
            // 等待运行
            Console.ReadLine();
        }

        static void consumerListener(IMessage message)
        {
            Console.WriteLine(message.GetType());
        }
    }

使用浏览器客户端发送消息
在javascript中发送消息

2. 解决

思路描述:
可以发现JavaScript发送的是BytesMessage，只要修改发送的数据为TextMessage类型就可以了，但是我没找到这种思路的解决方法
字符串解码
通过判断数据类型，如果是TestMessage就直接取出text就是utf-8形式的字符串，如果是BytesMessage就取出字节数组，将字节数组转成utf-8字符串就可以了

using Apache.NMS;
using Apache.NMS.ActiveMQ;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;

namespace Consumer
{
    internal class Program
    {
        static void Main(string[] args)
        {
            ConnectionFactory factory = new ConnectionFactory("tcp://localhost:61616");
            IConnection connection = factory.CreateConnection();
            connection.Start();
            ISession session = connection.CreateSession();
            IMessageConsumer consumer = session.CreateConsumer(new Apache.NMS.ActiveMQ.Commands.ActiveMQTopic("test_producer"));
            consumer.Listener += new MessageListener(consumerListener);
            // 等待运行
            Console.ReadLine();
        }

        static void consumerListener(IMessage message)
        {
            Console.WriteLine(message.GetType());
            string msg = StringUtils.ActiveMQMessageParse(message);
            Console.WriteLine("接收到->{0}", msg);
        }
    }

    public class StringUtils
    {
        /// <summary>
        /// 将字符串进行分割并获得字节数组
        /// </summary>
        /// <param name="str">待处理字符串</param>
        /// <param name="split">分割的字符串</param>
        /// <returns>字节数组</returns>
        public static byte[] StringToBytes(string str, char split)
        {
            string[] strArr = str.Split(split);
            byte[] byteArr = new byte[strArr.Length];
            for (int i = 0; i < strArr.Length; i++)
            {
                byteArr[i] = (byte)int.Parse(strArr[i]);
            }
            return byteArr;
        }

        /// <summary>
        /// 将字节数组转成字符串
        /// </summary>
        /// <param name="byteArr">字节数组</param>
        /// <param name="charSet">编码字符集</param>
        /// <returns></returns>
        public static string BytesToString(byte[] byteArr, CharSet charSet)
        {
            return Encoding.UTF8.GetString(byteArr, 0, byteArr.Length);
        }

        /// <summary>
        /// 将字符串根据分隔符转成字节数组，然后转成指定字符集的字符串
        /// </summary>
        /// <param name="str">待处理字符串</param>
        /// <param name="split">分割字符串</param>
        /// <param name="charSet">字符集</param>
        /// <returns>处理后的字符串</returns>
        public static string StringToString(string str, char split, CharSet charSet)
        {
            return BytesToString(StringToBytes(str, split), charSet);
        }

        /// <summary>
        /// 将ActiveMQ接收到的消息转换为UTF-8字符串
        /// </summary>
        /// <param name="message">接收到的数据</param>
        /// <returns></returns>
        public static string ActiveMQMessageParse(IMessage message)
        {
            string str = null;
            if (message is ITextMessage)
            {
                ITextMessage textMessage = (ITextMessage)message;
                try
                {
                    str = textMessage.Text;
                }
                catch (Exception e)
                {
                    Console.WriteLine(e.StackTrace);
                }
            }
            else if (message is IBytesMessage)
            {
                IBytesMessage bytesMessage = (IBytesMessage)message;
                byte[] byteArr = new byte[0];
                try
                {
                    byteArr = new byte[(int)bytesMessage.BodyLength];
                    int flag = bytesMessage.ReadBytes(byteArr);
                    str = BytesToString(byteArr, CharSet.Unicode);
                }
                catch (Exception ex)
                {
                    Console.WriteLine(ex.StackTrace);
                }
            }
            return str;
        }
    }
}