Chapter 3 Service Endpoint Design

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clarity, it is preferable to use this feature and embed value type references rath 

er than to use a single flat, large JAX RPC value type class.

4. The J2EE platform, because of its support for the SOAP message with attach 

ment protocol, also supports the use of MIME encoded content. It provides

Java mappings for a subset of MIME types. (See Table 3.1.)

Table 3.1

Mapping of MIME Types

MIME Type

Java Type

image/gif

java.awt.Image

image/jpeg

java.awt.Image

text/plain

java.lang.String

multipart/*

javax.mail.internet.MimeMultipart

text/xml

 or 

application/xml

javax.xml.transform.Source

Since the J2EE container automatically handles mappings based on the Java

types, using these Java MIME mappings frees you from the intricacies of sending

and retrieving documents and images as part of a service's request and response

handling. For example, your service, if it expects to receive a GIF image with a

MIME type of 

image/gif

, can expect the client to send a 

java.awt.Image

 object.

A sample Web service interface that receives an image might look like the one

shown in Code Example 3.3:

import java.awt.Image;

public interface WeatherMapService extends Remote {

public void submitWeatherMap(Image weatherMap)

throws RemoteException, InvalidMapException;

}

Code Example 3.3

Receiving a 

java.awt.Image

 Object

In this example, the 

Image

 object lets the container implementation handle the

image passing details. The container provides 

javax.activation.DataHandler

classes, which work with the Java Activation Framework to accomplish the Java 

MIME and MIME Java mappings.