Before you start
This tutorial is a complete guide to installing, configuring, building, and exercising (running) Web services that are based on remote procedure calls (RPCs). You'll download and install an implementation of the Java APIs for XML-Based RPC (JAX-RPC), learn how JAX-RPC is represented in Java classes and packages, and build both a client and server to allow for RPC-based interactions. Configuration options are covered, and you'll become comfortable deploying your own RPC-based applications.
This tutorial walks you through the construction of JAX-RPC Web services, from start to finish. More important, you'll see how all Web services are constructed. This tutorial covers the basics of client-server interactions in a service-based architecture and explores RPC simply as one implementation of those principles.
You'll also gain a thorough understanding of the JAX-RPC APIs, all in the context of practical use. Although you won't use every method of every class, you'll know which classes and methods are essential in a real-world context, and why some methods are not useful. All of these concepts are presented in the context of building one working RPC-based client and server.
Because service-based architectures are less direct — and somewhat harder to manage — than a typical client-server Web interaction (such as an HTML front-end making
POST requests to a Java servlet), they're harder to implement well. This tutorial explores some of the best practices for building Web services, as well as common mistakes.
- Understand the basics of JAX-RPC as they relate to the wider scope of Web services
- See how RPC-based services are different from SOAP- and REST-based services
- Understand when RPC services are still a good choice, despite some of the more "modern" approaches to Web services
This tutorial is written for Java programmers. You should be comfortable coding Java applications and working with standard and third-party Java APIs and toolkits.
You'll also need a Web server that's capable of hosting server-side Java applications (servlets). You can use any Java-capable Web servlet container, application server, or hosting provider. One of the most popular solutions is Apache Tomcat, which is both free and well-documented. It's also up to you whether you test out your programs on a remote server (at your company or an ISP), or on your local machine. You just need to have the server installed and running on an accessible machine. Details about how to configure JAX-RPC on those servers are included in the tutorial, so you don't need to understand the relationship between JAX-RPC's servlets and your Web server yet.
Knowledge of Java servlets and Apache Tomcat (particularly the servlet-hosting facilities and the web.xml deployment descriptor file) is helpful, although not strictly required.
See Resources for pointers to additional information on these topics.
This tutorial focuses on JAX-RPC and the Apache Axis open source implementation of JAX-RPC, but no previous knowledge of RPC, JAX-RPC, or Apache Axis is required. Details regarding their download, installation, and configuration are covered in the tutorial.