Chapter 2. JEUS Web Services

Table of Contents

2.1. Basic Architecture
2.2. Designing Web Services
2.2.1. Selecting a Web Service Backend
2.2.2. RPC-oriented and Document-oriented Information Exchanges
2.2.3. Web Service Implementation Methods
2.2.4. Creating SOAP Message Handlers

This chapter describes the concepts of JEUS web services and supported specifications. It also introduces the configuration files, tools, and system variables for JEUS web services.

JEUS 7, which conforms to Java EE 6, supports JAX-WS. The most useful feature of JAX-WS is the implementation of POJO(Plain Old Java Object) web services. JEUS web services guarantee compatibility with vendors that are JavaEE 6 compliant.

The following figure shows the structure of JEUS web services.


This section describes things to consider when designing web services.

Web service components are Java EE components that run in a web engine or an EJB container.

The following are the entities that can be published as a web service backend.

JEUS web services support RPC-oriented and document-oriented information exchanges.

The implementation of a web service can start out with a service endpoint or WSDL. Since each path has its own advantages, a developer can decide which path to take. They can be implementations of JAX-WS and JAX-RPC JEUS web services.

Starting with Web Service Endpoint

By starting out with creating a web service endpoint, developers can generate a WSDL file from it. This method has the advantages of an easy and intuitive implementation process. This enables a developer to develop service endpoint and implementation in a familiar environment without having to worry about interoperability with other platforms in a Java environment. The developer can then derive a platform independent WSDL from the Java codes.

JAX-WS and JAX-RPC provide guidelines on how to derive WSDL from service endpoints so that WSDL can be platform independent. This is the easiest method for developing web services for JAVA developers.

Starting with WSDL

First create a WSDL file, and then generate web service Implementation from it.

Core objective of a web service is its interoperability with different platforms. This method is appropriate for generating interoperable service that is independent of the programming language. The platform's characteristics will be reflected in the WSDL generated from a web service implementation, leaning towards Java. The descriptions derived from a WSDL, on the other hand, are more neutral than the XML types and terms used for web service descriptions. This allows developers who are not familiar with the Java language to create a WSDL using general nomenclature.

However, it will require developers to have a deeper understanding of WSDL. JAX-WS web service implementation is discussed in "Chapter 3. JEUS Web Service Implementation", and JAX-RPC web service implementation is described in "Chapter 20. Implementing JAX-RPC Web Services".