轻量消息队列（原 MNS）：队列使用示例

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

发送消息

• 运行sendmessage.py，命令如下：

  python sendmessage.py MyQueue1

  返回结果如下：

  ==========Send Message To Queue==========
  QueueName:MyQueue1
  MessageCount:3
  
  Send Message Succeed! MessageBody:I am test message 0. MessageID:3EBE662B52BC99BC-1-154BD99CCA7-200000001
  Send Message Succeed! MessageBody:I am test message 1. MessageID:64B92941FC57837F-2-154BD99CCCE-200000001
  Send Message Succeed! MessageBody:I am test message 2. MessageID:3EBE662B52BC99BC-1-154BD99CCF0-200000002

• 核心代码：

  my_account = Account(endpoint, accid, acckey, token)
  queue_name = sys.argv[1] if len(sys.argv) > 1 else "MySampleQueue"
  my_queue = my_account.get_queue(queue_name)
  
  msg_count = 3
  
  print("%sSend Message To Queue%s\nQueueName:%s\nMessageCount:%s\n" % (10*"=", 10*"=", queue_name, msg_count))
  for i in range(msg_count):
      try:
          msg_body = u"I am test message %s." % i
          msg = Message(msg_body)
          re_msg = my_queue.send_message(msg)
          print("Send Message Succeed! MessageBody:%s MessageID:%s ReceiptHandle:%s" % (msg_body, re_msg.message_id, re_msg.receipt_handle))
      except MNSExceptionBase as e:
          if e.type == "QueueNotExist":
              print("Queue not exist, please create queue before send message.")
              sys.exit(0)
          print("Send Message Fail! Exception:%s\n" % e)

接收和删除消息

• 运行recvdelmessage.py，命令如下：

  python recvdelmessage.py MyQueue1                

  返回结果如下：

  ==========Receive And Delete Message From Queue==========
  QueueName:MyQueue1
  WaitSeconds:3
  
  Receive Message Succeed! ReceiptHandle:1-ODU4OTkzNDU5My0xNDYzNDcwNDU4LTEtOA== MessageBody:I am test message 0. MessageID:3EBE662B52BC99BC-1-154BD99CCA7-200000001
  Delete Message Succeed!  ReceiptHandle:1-ODU4OTkzNDU5My0xNDYzNDcwNDU4LTEtOA==
  Receive Message Succeed! ReceiptHandle:1-ODU4OTkzNDU5NC0xNDYzNDcwNDU4LTEtOA== MessageBody:I am test message 2. MessageID:3EBE662B52BC99BC-1-154BD99CCF0-200000002
  Delete Message Succeed!  ReceiptHandle:1-ODU4OTkzNDU5NC0xNDYzNDcwNDU4LTEtOA==
  Receive Message Succeed! ReceiptHandle:1-ODU4OTkzNDU5My0xNDYzNDcwNDU4LTItOA== MessageBody:I am test message 1. MessageID:64B92941FC57837F-2-154BD99CCCE-200000001
  Delete Message Succeed!  ReceiptHandle:1-ODU4OTkzNDU5My0xNDYzNDcwNDU4LTItOA==
  Queue is empty!

• 核心代码：

  my_account = Account(endpoint, accid, acckey, token)
  queue_name = sys.argv[1] if len(sys.argv) > 1 else "MySampleQueue"
  base64 = False if len(sys.argv) > 2 and sys.argv[2].lower() == "false" else True
  my_queue = my_account.get_queue(queue_name)
  my_queue.set_encoding(base64)
  
  wait_seconds = 3
  print("%sReceive And Delete Message From Queue%s\nQueueName:%s\nWaitSeconds:%s\n" % (10*"=", 10*"=", queue_name, wait_seconds))
  while True:
      try:
          // receive_message 返回消息的消息体为字节串，receive_message_with_str_body 返回消息的消息体为字符串
          // recv_msg = my_queue.receive_message(wait_seconds)
          recv_msg = my_queue.receive_message_with_str_body(wait_seconds)
          print("Receive Message Succeed! ReceiptHandle:%s MessageBody:%s MessageID:%s" % (recv_msg.receipt_handle, recv_msg.message_body, recv_msg.message_id))
      except Exception as e:
          if hasattr(e, 'type'):
              if e.type == u"QueueNotExist":
                  print("Queue not exist, please create queue before receive message.")
                  sys.exit(0)
              elif e.type == u"MessageNotExist":
                  print("Queue is empty!")
                  sys.exit(0)
          print("Receive Message Fail! Exception:%s\n" % e)
          continue
  
      try:
          my_queue.delete_message(recv_msg.receipt_handle)
          print("Delete Message Succeed!  ReceiptHandle:%s" % recv_msg.receipt_handle)
      except Exception as e:
          print("Delete Message Fail! Exception:%s\n" % e)