Simple Message Queue (formerly MNS):PeekMessage

Authorization

By default, only Alibaba Cloud accounts can call this operation. RAM users can call this operation only after these RAM users are granted related permissions. The following table describes the authorization information of this operation. For more information, see Permission policies and examples.

Description

You can call this operation to query a message. Different from the ReceiveMessage operation, the PeekMessage operation does not change the status of the message. After you call the PeekMessage operation to view a message, the message remains in the Active state and can still be viewed or consumed. However, if you call the ReceiveMessage operation to receive a message, the message changes to the Inactive state. Then, the message cannot be viewed or consumed by other clients within the period specified by the VisibilityTimeout parameter.

Request

A request consists of the following parts:

• Request line

  GET /queues/$queueName/messages?peekonly=true HTTP/1.1

• URI parameters

  peekonly=true indicates that this request is only used to view a message in the queue and does not change the status of the message.

• Operation-specific request headers

  None.

• Request body

  None.

Response

A response consists of the following parts:

• HTTP status code

  HTTP/1.1 200 OK

• Operation-specific response headers

  None.

• Response body

  The response body is in the XML format. The body and parameters of the message are returned.

  Parameter	Type	Example	Description
  MessageId	String	D6D5F7C9C12D14A4-1-14D953EFC72-20000****	The ID of the message. The message ID is unique in the queue.
  MessageBody	String	This is a test message.	The body of the message.
  MessageBodyMD5	String	F9360F391579E71CA77BC5D50242****	The MD5 hash of the message body.
  EnqueueTime	Long	1250700979248	The time when the message was sent to the queue. This value is a UNIX timestamp representing the number of milliseconds that have elapsed since the epoch time January 1, 1970, 00:00:00 UTC.
  FirstDequeueTime	Long	1250700979348	The first time the message was consumed. This value is a UNIX timestamp representing the number of milliseconds that have elapsed since the epoch time January 1, 1970, 00:00:00 UTC. If the value of the DequeueCount parameter is 0, the value of the FirstDequeueTime parameter is the same as the value of the EnqueueTime parameter.
  DequeueCount	Integer	5	The total number of times for which the message was consumed.

Examples

Sample requests

GET  /queues/$queueName/messages?peekonly=true HTTP/1.1
Host: $AccountId.mns.cn-hangzhou.aliyuncs.com
Date: Wed, 28 May 2012 22:32:00 GMT
x-mns-version: 2015-06-06
Authorization: MNS 15B4D3461F177624206A:xQE0diMbLRepdf3YB+FIEXA****           

Sample success responses

HTTP/1.1 200 OK
Connection:close
Content-Type=text/xml;charset=utf-8
Content-Length:500
x-mns-request-id:512B2A634403E52B1956****
x-mns-version: 2015-06-06

<?xml version="1.0" encoding="UTF-8"?>
<Message xmlns="http://mns.aliyuncs.com/doc/v1/">
    <MessageId>D6D5F7C9C12D14A4-1-14D953EFC72-20000****</MessageId>
    <MessageBodyMD5>F9360F391579E71CA77BC5D50242****</MessageBodyMD5>
    <MessageBody>This is a test message.</MessageBody>
    <EnqueueTime>1250700979248</EnqueueTime>
    <FirstDequeueTime>1250700979348</FirstDequeueTime >
    <DequeueCount>5</DequeueCount>
    <Priority>8<Priority>
</Message>            

Error codes