Web Services

Web services are classified into two categories:

SOAP – In SOAP-based web services both client and service transfer SOAP messages to communicate.
REST – While in REST-style services both client and service usually transfer raw XML to communicate.
Java provides API for creating both SOAP and REST-style web services

JAX-WS – JAX-WS (Java API for XML Web Services) is a Java API for creating both SOAP and REST-style web services. There is a common misconception that JAX-WS is only for SOAP-based services, which is not true. Using JAX-WS you can create both SOAP and REST-style services

JAX-RS – JAX-RS (Java API for RESTful Web Services) is a Java API to write RESTful web services easily

Web Services Overview
Interoperable applications with Service-Oriented Architecture (SOA)

Designing an SOA integration architecture
Evaluating alternatives to SOA
Implementing SOA with Web services

Core technologies: HTTP, XML, SOAP, WSDL
What SOA does not provide
XML Processing in Java
XML essentials

XML syntax and namespaces
Describing XML with schema
Interacting with XML from Java

Marshaling and unmarshaling with JAXB
Customizing XML to Java bindings
Defining SOAP Messages with WSDL
Structure of SOAP messages

Role of SOAP in Web services
Operations, messages and faults
Anatomy of a WSDL document

Defining the interfaces of a Web service
Specifying implementation
Deploying WSDL
Generating WSDL-first Web Services
Architecting a Web Service

Designing a service endpoint
Specifying protocol of message interchange
Preserving flexibility and extensibility
Importing a WSDL document

Building interoperable applications by conforming to Web Services Interoperability (WSI) standards
Incorporating Web service proxies and adapters
Implementing a Web service end point using JAX-WS
Customizing JAX-WS Web services

Deploying a Web service WAR file
Intercepting traffic between Web services and clients
Optimizing message transmission
Exposing Plain Old Java Objects (POJOs) as Web Services
Implementing code-first Web services

Choosing between WSDL-first and code-first Web services
Generating portable artifacts using JAX-WS
Preserving maintainability with proxies and adapters
Designing reliable and scalable services

Creating highly parallel Web services
Bulletproofing multithreaded Web services
Improving generated WSDL

Annotating Java services
Deploying end points
Implementing Web Service Clients in Java
Generating client code from WSDL

Accessing Web services through their WSDL
Creating client source files from WSDL
Customizing generated source files with JAX-WS
Synchronous, polling and asynchronous services

Designing and creating one-way services and clients
Writing multithreaded clients
Interception and modifying SOAP messages
Soap Message Processing

Logical Handler and Soap Handler
Soap Header Processing, Soap Actors
Document vs. RPC style messaging
RESTful Web Services for Interactivity
Stateless processing of XML requests

Building RESTful Web services using JAX-RS
Implementing a Provider
Providing client-side interactivity
Lightweight clients

Invoking Web Services with the Dispatch API
Processing received XML messages
Securing Web Services
Authenticating and authorizing clients

Limiting access to Web services and methods
Providing authentication information to Web services
Message-level security

Transport security vs. end-to-end security
Turning on WS-Security