Java Technology and Web Services

The Web services are Web-based enterprise applications that use open, XML-based standards and transport protocols to exchange data with calling clients. Java 2 Platform, Enterprise Edition (J2EE) provides the APIs and tools you need to create and deploy interoperable Web services and clients.

Java Technology and Web Services is organized into these subcategories:
Java Web Services Developer Pack (Java WSDP)
Java API for XML-Based RPC (JAX-RPC)
Java API for XML Registries (JAXR)
Java API for XML Processing (JAXP)
Java Architecture for XML Binding (JAXB)
SOAP with Attachments API for Java (SAAJ)
XML and Web Services Security

Web Services Overview:

- Extensible Markup Language (XML)
- Web Services/XML APIs
- Java Platform Tools

The Java 2 Platform, Enterprise Edition platform provides the APIs and tools you need to quickly design, develop, test, and deploy Web services and clients that fully interoperate with other Web services and clients running on any platform. This full interoperability is possible because application data is translated "behind-the-scenes" to a standardized XML-based data stream.

A brief overview of XML, APIs, and tools is presented here. See also The J2EE Tutorial for detailed information with examples.

Extensible Markup Language (XML)
Extensible Markup Language (XML) is a cross-platform, extensible, and text-based standard for representing data. When XML data is exchanged between parties, the parties are free to create their own tags to describe the data, set up schemas to specify which tags can be used in a particular kind of XML document, and use XML style sheets to manage the display and handling of the data.

Web Services/XML APIs
It is easy to write Web services and clients with the J2EE XML APIs. All you do is pass parameter data to the method calls and process the data returned, or for document-oriented web services, send documents containing the service data back and forth. No low-level programming is needed. The following list describes the Web services/XML APIs.

The Java API for XML Processing (JAXP) supports the processing of XML documents using Document Object Model (DOM), Simple API for XML Parsing (SAX), and XML Style sheet Language Transformation (XSLT). The JAXP API enables applications to parse and transform XML documents independently of a particular XML processing implementation.

The Java API for XML Registries (JAXR) lets you access business and general-purpose registries over the Web. JAXR supports the ebXML Registry/Repository standards and the UDDI specifications.

The Java API for XML-based RPC (JAX-RPC) uses the SOAP standard and HTTP so client programs can make XML-based remote procedure calls (RPCs) over the Internet. JAX-RPC also supports WSDL so you can import and export WSDL documents. With JAX-RPC and a WSDL, you can easily interoperate with clients and services running on Java-based or non-Java-based platforms such as .NET.

The SOAP with Attachments API for Java (SAAJ) enables you to produce and consume messages conforming to the SOAP 1.1 specification and SOAP with Attachments note.

Java Platform Tools
Web Services/XML works with an array of tools including Integrated Development Environments (IDEs), performance and testing tools, and performance monitoring tools.