The body of an object message contains a serialized Java or .NET object.
An XMS application can receive an object message, change its header fields and properties, and then send it to another destination. An application can also copy the body of an object message and use it to form another object message. XMS treats the body of an object message as an array of bytes.
After an application creates an object message, the body of the message is readable and writable. The body remains readable and writable after the application sends the message. When an application receives an object message, the body of the message is read-only. If an application calls the Clear Body method of the Message class for C or C++ or of the IMessage interface for .NET when the body of an object message is read-only, the body becomes readable and writable. The method also clears the body.