Simple Message Queue (formerly MNS):Message attributes

Write message attributes

// 1. Create a message object.
Message message = new Message();
message.setMessageBody("This is the message content");

// 2. Create a map to store the message attributes.
Map<String, MessagePropertyValue> userProperties = new HashMap<>();

// 3. Add attributes for each supported type.
// String
userProperties.put("city", new MessagePropertyValue("hangzhou"));
// Number (integer)
userProperties.put("priority", new MessagePropertyValue(10));
// Number (floating-point number)
userProperties.put("temperature", new MessagePropertyValue(-5.5));
// Boolean
userProperties.put("is_vip", new MessagePropertyValue(true));
// Binary
byte[] binaryData = "some-binary-data".getBytes();
userProperties.put("attachment", new MessagePropertyValue(binaryData));

// 4. Set the attributes for the message.
message.setUserProperties(userProperties);

Read message attributes

// Assume that 'receivedMessage' is a message object that you have obtained.
// Message receivedMessage = ...; 

// 1. Get the attribute map from the message.
Map<String, MessagePropertyValue> userProperties = receivedMessage.getUserProperties();

if (userProperties != null && !userProperties.isEmpty()) {
    // 2. Read and parse the attributes of each type.
    // Read String
    String city = userProperties.get("city").getStringValue();
    System.out.println("City (String): " + city);

    // Read Number (and parse as Double)
    double temperature = Double.parseDouble(userProperties.get("temperature").getStringValue());
    System.out.println("Temperature (Number as Double): " + temperature);

    // Read Number (and parse as Integer)
    int priority = Integer.parseInt(userProperties.get("priority").getStringValue());
    System.out.println("Priority (Number as Integer): " + priority);

    // Read Boolean (and parse)
    boolean isVip = Boolean.parseBoolean(userProperties.get("is_vip").getStringValue());
    System.out.println("Is VIP (Boolean): " + isVip);

    // Read Binary
    byte[] attachment = userProperties.get("attachment").getBinaryValue();
    System.out.println("Attachment (Binary): " + new String(attachment));
}

Queue subscriptions

When a message is pushed to a Simple Message Queue (formerly MNS) queue subscription endpoint, the message attributes are passed as part of the Message object. You can receive the message in the same way as a normal message, and then access userProperties using the methods that the Message object provides. For an example, see Read message attributes.

HTTP subscriptions

When a message is pushed to an HTTP subscription endpoint, the format of the message attributes depends on the Message Format that you specify when you create the subscription (the NotifyContentFormat property of the subscription):

• JSON: If the format is JSON, the UserProperties message attributes are included as a JSON object in the body of the pushed HTTP POST request. Each attribute contains a Type field and a Value field.

  JSON example

  {
    "TopicOwner": "1234567890",
    "TopicName": "MyTopic",
    "Subscriber": "1234567890",
    "SubscriptionName": "MySubscription",
    "Message": "This is a test message.",
    "MessageId": "A26DAA0E-26C1-5F09-8BCC-CA3F1590A308",
    "MessageMD5": "E784F7B224E9164608EAD4CC76410443",
    "TimeStamp": "2025-02-20T13:41:37.976Z",
    "UserProperties": {
      "source": {
        "Type": "STRING",
        "Value": "mobile-app"
      },
      "image_id": {
        "Type": "NUMBER",
        "Value": "98014"
      },
      "raw_data": {
        "Type": "BINARY",
        "Value": "aGVsbG8gd29ybGQ="
      }
    }
  }

• XML: If the format is XML, the UserProperties message attributes are included as an XML element in the body of the pushed HTTP POST request.

  XML example

  <?xml version="1.0" encoding="UTF-8"?>
  <Notification>
      <TopicOwner>1234567890</TopicOwner>
      <TopicName>MyTopic</TopicName>
      <Subscriber>1234567890</Subscriber>
      <SubscriptionName>MySubscription</SubscriptionName>
      <Message>This is a test message.</Message>
      <MessageId>A26DAA0E-26C1-5F09-8BCC-CA3F1590A308</MessageId>
      <MessageMD5>E784F7B224E9164608EAD4CC76410443</MessageMD5>
      <TimeStamp>2025-02-20T13:41:37.976Z</TimeStamp>
      <UserProperties>
          <PropertyValue>
              <Name>source</Name>
              <Value>mobile-app</Value>
              <Type>STRING</Type>
          </PropertyValue>
          <PropertyValue>
              <Name>image_id</Name>
              <Value>98014</Value>
              <Type>NUMBER</Type>
          </PropertyValue>
          <PropertyValue>
              <Name>raw_data</Name>
              <Value>aGVsbG8gd29ybGQ=</Value>
              <Type>BINARY</Type>
          </PropertyValue>
      </UserProperties>
  </Notification>

• SIMPLIFIED: If the format is SIMPLIFIED, Simple Message Queue (formerly MNS) pushes only the raw message content. Message attributes cannot be passed.