Web Services in J2EE





Web Services in J2EE

Given the road map outlined by the SOA, it is possible to map how this architecture should be supported relative to the J2EE platform. To describe this mapping, the JCP introduced two standards—JAX-RPC (JSR-101) and JSR-109—that represent the core infrastructure of J2EE based-Web services.

The JAX-RPC specification identifies the client and server programming model for J2EE based-Web services. In addition, is also defines the Java-to-WSDL type mappings. The JAX-RPC specification defines the core APIs, as well as mappings from XML/WSDL to Java and Java to XML/WSDL. It is this specification that defines how tools take a Java interface and produce a WSDL document. Likewise, a WSDL document can be converted into a set of Java classes that can, in turn, be used to invoke a service specified by the WSDL document.

The Web Services for J2EE (JSR-109) specification complements JAX-RPC by extending the programming model into the J2EE environment. JSR 109 defines how J2EE services are to be deployed into the runtime environment. This includes refinement of the client and server programming models, the deployment model, handler support, and WSDL publication rules.

Figure illustrates the relationships between the specifications that comprise the J2EE Web services environment.[5]

[5] Note that although JAX-RPC and JSR 109 are supported by WAS 5.0.2, they are not officially part of J2EE until release 1.4. Likewise, JAXP and SAAJ are presented here for completeness.

2. Relationship between Java and Web services specifications.

graphics/32fig02.gif


     Python   SQL   Java   php   Perl 
     game development   web development   internet   *nix   graphics   hardware 
     telecommunications   C++ 
     Flash   Active Directory   Windows