轻量消息队列（原 MNS）：主题使用示例

前提条件

• 已安装SDK。

• 已配置访问域名及凭证。

  重要

  • 本文代码中提及的endpoint从配置访问域名时的sample.cfg文件中读取，accid、acckey和 token从环境变量中读取。

  • 示例代码下载，请参见示例代码。

消息体编码选择

对消息体是否进行Base64编码，请参见消息体编码选择指南。

发布消息

• 运行publishmessage.py发布多条消息到主题中，命令如下：

  python publishmessage.py MyTopic1        

  返回结果如下：

  ==========Publish Message To Topic==========
  TopicName:MyTopic1
  MessageCount:3
  
  Publish Raw Message Succeed. MessageBody:I am test message 0. MessageID:4EA4CF419C3A7FC67FA95077****0001
  Publish Raw Message Succeed. MessageBody:I am test message 1. MessageID:4EA4CF419C3A7FC67FA95077****0002
  Publish Raw Message Succeed. MessageBody:I am test message 2. MessageID:4EA4CF419C3A7FC67FA95077****0003
  Publish Base64 Encoded Message Succeed. MessageBody:I am test message 0. MessageID:4EA4CF419C3A7FC67FA95077****0004
  Publish Base64 Encoded Message Succeed. MessageBody:I am test message 1. MessageID:4EA4CF419C3A7FC67FA95077****0005
  Publish Base64 Encoded Message Succeed. MessageBody:I am test message 2. MessageID:4EA4CF419C3A7FC67FA95077****0006

• 核心代码：

  my_account = Account(endpoint, accid, acckey, token)
  topic_name = sys.argv[1] if len(sys.argv) > 1 else "MySampleTopic"
  my_topic = my_account.get_topic(topic_name)
  
  msg_count = 3
  print("%sPublish Message To Topic%s\nTopicName:%s\nMessageCount:%s\n" % (10*"=", 10*"=", topic_name, msg_count))
  
  for i in range(msg_count):
      try:
          msg_body = u"I am test message %s." % i
          msg = TopicMessage(msg_body)
          re_msg = my_topic.publish_message(msg)
          print("Publish Raw Message Succeed. MessageBody:%s MessageID:%s" % (msg_body, re_msg.message_id))
      except MNSExceptionBase as e:
          if e.type == "TopicNotExist":
              print("Topic not exist, please create it.")
              sys.exit(1)
          print("Publish Raw Message Fail. Exception:%s" % e)
  
  for i in range(msg_count):
      try:
          msg_body = u"I am test message %s." % i
          msg = Base64TopicMessage(msg_body)
          re_msg = my_topic.publish_message(msg)
          print("Publish Base64 Encoded Message Succeed. MessageBody:%s MessageID:%s" % (msg_body, re_msg.message_id))
      except MNSExceptionBase as e:
          if e.type == "TopicNotExist":
              print("Topic not exist, please create it.")
              sys.exit(1)
          print("Publish Base64 Encoded Message Fail. Exception:%s" % e)