561. Developing Java Web Services
Version 2.1

A comprehensive look at the state of the art in developing interoperable web services on the Java EE platform.  Students learn the key standards -- SOAP, WSDL, and the WS-I Basic Profile -- and the Java architecture that has evolved to build interoperable services and clients.  JAX-WS is central to the course, and we cover both WSDL-driven and Java-driven development paths, as well as message handlers and attachment support.  With the new Provider and Dispatch APIs, it's now much easier to integrate SAAJ, JAXB, and JAXP code into services and clients, and we explore these strategies in depth as well.

(For training within the J2EE 1.4 environment, and a concentration on JAX-RPC and SAAJ, please see version 1.5.3 of this course.)

Prerequisites

  * Strong Java programming skills are essential -- Course 103 is excellent preparation.
  * Students must be able to read XML documents and to write well-formed XML by hand -- consider Course 501.  Knowledge of XML Schema will be helpful, too, but is not a strict prerequisite.
  * Experience with other Java EE standards, especially servlets and JSP, will be very helpful in class, but is not strictly required.

Learning Objectives

  * Be able to describe the interoperable web services architecture, including the roles of SOAP and WSDL.
  * Understand the importance of the WS-I Basic Profile for interoperable web services.
  * Build JAX-WS services and clients that take full advantage of the automated data binding of JAXB.
  * Use lower-level SOAP and XML APIs for services and/or clients.
  * Customize data binding by specifying specific type mappings or altering method or parameter names.
  * Expose session beans as web services.
  * Incorporate binary data, such as images, into service and client code.

Timeline: 5 days.

IDE Support: Eclipse Galileo

In addition to the primary lab files, an optional overlay is available that adds support for Eclipse Galileo.  Students can code and compile all exercises from within Eclipse; deployment to the server is Ant-driven and can be triggered from the IDE as well.  See also our orientation to Using Capstone's Eclipse Overlays, and please be advised that this is an optional feature; it is not a separate version of the course, and the course itself does not contain explicit Eclipse-specific lab instructions.

Chapter 1. Overview of Web Services
    Why Web Services?
    Service-Oriented Architecture
    HTTP and XML
    Simple Object Access Protocol (SOAP)
    Web Service Description Language (WSDL)
    Universal Description, Discovery and Integration (UDDI)
    The WS-I Basic and Related Profiles
    REST

Chapter 2. Web Services for Java EE
    Hosting Web Services: Scenarios
    Invoking Web Services: Scenarios
    Web Services for Java EE (WS4JEE)
    The Automated Approach: JAX-WS and JAXB
    Manual Options: SAAJ and JAXP
    Portable Web-Services Metadata
    Service Registries: JAXR

Chapter 3. The Simple Object Access Protocol
    Messaging Model
    Namespaces
    SOAP over HTTP
    The SOAP Envelope
    The Message Header
    The Message Body
    SOAP Faults
    Attachments

Chapter 4. The Java API for XML Binding
    The Need for Data Binding
    XML Schema
    Two Paths
    JAXB Compilation
    Mapping Schema Types to Java
    Java-to-XML Mapping Using Annotations
    Marshaling and Unmarshaling
    Working with JAXB Object Models
    In-Memory Validation

Chapter 5. Web Services Description Language
    Web Services as Component-Based Software
    The Need for an IDL
    Web Services Description Language
    WSDL Information Model
    The Abstract Model -- Service Semantics
    Message Description
    Messaging Styles
    The Concrete Model -- Ports, Services, Locations
    Extending WSDL -- Bindings
    Service Description

Chapter 6. The Java API for XML-Based Web Services
    Two Paths
    How It Works: Build Time and Runtime
    The Service Endpoint Interface
    Working from WSDL
    Working from Java
    RPC and Document Styles
    One-Way Messaging
    Binary Protocols

Chapter 7. WSDL-to-Java Development
    The @WebService Annotation
    Generated Code
    Compilation and Assembly
    Deployment
    Runtime Behavior
    Scope of Code Generation
    More JAXB: Mapping Collections
    More JAXB: Mapping Enumerations
    Throwing Exceptions

Chapter 8. Client-Side Development
    Stubs and Proxies
    Generated Code
    Locating a Service
    Invoking a Service
    Exception Handling

Chapter 9. Java-to-WSDL Development
    The @WebMethod, @XmlParam, and Related Annotations
    Scope of Code Generation
    More JAXB: Mapping Inheritance
    Controlling the XML Model
    Controlling the WSDL Description

Chapter 10. JAX-WS Best Practices
    Which Way to Go?
    Interoperability Impact
    Portability Impact
    Polymorphism in Web Services
    Web Services as Java EE Components
    Lifecycle Annotations
    Context Interfaces
    The @WebServiceRef Annotation

Chapter 11. Provider and Dispatch APIs
    Stepping Down
    The Provider<T> Interface
    Implementing a Provider
    JAXB Without WSDL
    Integrating JAXP
    The Dispatch<T> Interface
    Building Clients

Chapter 12. The SOAP with Attachments API for Java
    The SAAJ Object Model
    Parsing a SOAP Message
    Reading Message Content
    Working with Namespaces
    Creating a Message
    Setting Message Content

Chapter 13. Message Handlers
    Handling SOAP Headers
    Servlet Endpoint Context
    MessageContext and SOAPMessageContext
    Message Handlers and Handler Chains
    Processing Model and Patterns
    Client-Side Handlers

Chapter 14. EJBs as Web Services
    Enterprise JavaBeans
    Three Tiers for Java EE
    EJB3 and JAX-WS
    Session Beans as Web Service Endpoints
    The Bean's Service Endpoint Interface
    SOAP as an EJB Protocol
    Pitfalls

Chapter 15. Handling Binary Content
    The WS-I Attachments Profile
    Using base64Binary
    MIME Attachments
    JAX-WS Support
    MTOM and XOP
    SAAJ Support

Appendix A. Learning Resources

Appendix B. Compatibility and Migration
    JAX-RPC
    Comparing JAX-RPC and JAX-WS
    Using JAX-RPC and JAX-WS Together
    SOAP "Section 5" Encoding

Appendix C. Quick Reference: Web-Services Acronyms

System Requirements

    Hardware, Minimum: 1 GHz, 512 meg RAM, 1 gig disk space.

    Hardware, Recommended: 2 GHz, 1 gig RAM, 1 gig disk space.

    Operating System: Tested on Windows XP Professional.  Course software should be viable on all systems which support the Java EE 5.0 SDK.

    Network and Security: Limited privileges required -- please see our standard security requirements at http://capcourse.com/Guides/Security.gen.html.

    Software Requirements:  All free downloadable tools.