1. Using Oracle Messaging Cloud Service
  2. Accessing Oracle Messaging Cloud Service Using REST API
  3. Properties of HTTP Requests to Send Messages from REST Clients

Properties of HTTP Requests to Send Messages from REST Clients

This section provides information about properties of HTTP requests to send messages from REST clients.

Topics:

Request Parameters

This section provides information about request parameters which can be used when sending messages using the REST API.

correlationId

Optional. No default.

This parameter is used to group together (correlate) multiple messages.

For the query string parameter correlationId, the equivalent HTTP header is X-OC-CORRELATION-ID.

deliveryMode

Optional. If present, value must be persistent or non_persistent; default is persistent. Determines whether the message is persistent (that is, stored by the JMS broker in persistent storage until delivered).

For the query string parameter deliveryMode, the equivalent HTTP header is X-OC-DELIVERY-MODE. 

messageType

Optional; if omitted, the default is HTTP. This parameter specifies the type of JMS message the HTTP request will cause to be generated. Depending on the value, there may be restrictions on the HTTP request body, and/or special interpretation of that body and/or some of the standard HTTP request parameters.

For the query string parameter messageType, the equivalent HTTP header is X-OC-MESSAGE-TYPE.

See Message Types for information about the valid values for the messageType query string parameter along with any required formatting for the HTTP request body. 

replyTo

Optional. If present, must have one of the following forms:

  • /queues/queueName

  • /temporaryQueues/queueName

  • /topics/topicName

  • /temporaryTopics/topicName

Specifies a destination or a temporary destination to which replies should be sent.

For the query string parameter replyTo, the equivalent HTTP header is X-OC-REPLY-TO.

ttl

Optional. If present, value must be a strictly positive long integer or the value maximum. Determines the time in milliseconds between when the message is dispatched and when the service may delete it if not yet delivered. The semantics of these parameters is the same as the corresponding parameters for producers, but the default is defined by the producer, and is overridden by any headers occurring in this operation.

For the query string parameter ttl, the equivalent HTTP header is X-OC-TTL.

HTTP Headers to Specify Message Properties

The HTTP request headers (when sending messages) can specify messaging properties for the message being sent.

X-OC-propertyType-PROPERTY-propertyName

Optional. This is not a single header, but a family of headers, referred to collectively as message property headers, one for each property type and property name. The property name value should consist of alphanumeric characters and underscores, and is made lower-case by the service. This sets the message property with name property name on the message to value property value, if the property type is one of the allowed values and property value is a value allowed for the property type. See Message Headers and Properties for information about the allowed values of property type.

Limitations on Message Size

Oracle Messaging Cloud Service only allows messages with at most 3K (3072) characters of messaging-relevant HTTP request headers and at most 512K (524,288) bytes or characters of HTTP request body. An attempt to send a message that exceeds these limits will generate an error response, and no message will be sent. Details of this limitation are as follows:

  • An HTTP request header is messaging-relevant if its name begins with X-OC- (case-insensitive); if the message type is HTTP, or is not supplied (in which case it defaults to HTTP), the Content-Type and Content-Language headers are also messaging-relevant.

  • The number of characters in a messaging-relevant header is the sum of the number of characters in the header name and the number of characters in the header value.

  • If the message has no type, or has type BYTES, OBJECT, or HTTP, the size of the HTTP request body is measured in bytes, and is counted as in the HTTP specification.

  • If the message has type TEXT, MAP, or STREAM, the size of the HTTP request body is measured in characters according to the character encoding.

  • If the message has type PLAIN, the request body is ignored, and so has size 0 for purposes of size limitations.

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