O'Reilly and Associates, Inc. publishes an entire series of books on Java programming. You can find a complete list of Java books from O'Reilly and Associates at http://java.oreilly.com. Books that are of particular interest to Java developers working with web services include:
A Java language tutorial and complete API reference for the core Java classes.
A tutorial and API reference for many of Java's enterprise API's, including EJBs and servlets, both of which can be used to host Java web services.
Although it is possible to create and use simple web services without much understanding of XML, a proper grounding in this important subject is required to make use of the more advanced features. Brett McLaughlin's Java and XML provides both an introduction to XML and good coverage of many of the XML-based technologies that are relevant to web services.
This book provides detailed coverage of the XML schema language, a knowledge of which is useful if you want to be able to read web service definitions written using WSDL, or if you intend to use the lower-level web service APIs, such as SAAJ.
Provides comprehensive coverage of Ant , which is now the tool that is most commonly used by development teams to build their software, and which is required to compile and run the example source code for this book.