Chapter 5 Client Design

245

foo.jad

META INF

manifest.mf

Client class files

Generated stub and dependent classes

Service endpoint interface

Generated classes

 foo.jar

Figure 5.11

Packaging a MIDlet Web Service Client Application

A developer may also provide an external Java Application Descriptor (JAD)

file for the MIDlet. A JAD file provides the J2ME environment with additional

information about the application, such as the location of the application's MIDlet

file. A JAD file's attributes mirror those found in the manifest file, but the JAD

file takes precedence over the manifest file. Furthermore, a developer or deployer

may override application attributes in the JAD file. Figure 5.11 describes the

packaging for a Web service MIDlet client application.

The 

foo.jar

 MIDlet file contains the client application classes and the respec 

tive artifacts generated by the J2ME Web service development tools, as well as a

manifest file. A foo.jad file describes the 

foo.jar

 MIDlet. Similar to the J2EE

platform, the J2ME platform with the optional Web service packages provides the

resources required for Web service communication.

5.5

Conclusion

This chapter described the different types of clients that may access Web services

and the issues faced by developers of these clients. It highlighted the differences

between clients running in a J2EE environment from clients running in the J2SE and

J2ME environments, and how these differences affect the design of a client applica 

tion. 

The chapter described the three communication modes available to clients:

stubs, dynamic proxy, and dynamic invocation interface. These three modes form

the basis for a client's access to a Web service. For each communication mode, the