How to get started with java web-services?

I am intermediate in java now I am planning to move to java web-services... How can i get started with web-services?

What are the prerequisites?

Thank开发者_JAVA技巧s...

To get started with web services in Java, I would recommend to use the Java API for XML Web Services A.K.A. JAX-WS. The reference implementation of this API (JAX-WS RI) is included in Java 6 (since Java 6 update 4) so you don't have anything to install if you are using Java 6u4+. Like the other APIs of Java EE, JAX-WS uses annotations to simplify the development and deployment of web service clients and endpoints. This API supports both Java-first and contract-first approaches (the former begin debatable but, well, this is the easiest way to get started).

You'll find many good tutorials on the NetBeans website, see Getting Started with JAX-WS Web Services or Developing JAX-WS Web Service Clients for example. When it comes to web services, I must say that NetBeans has actually far more better support than Eclipse and would be my recommend IDE. I do not want to go to much into the details (because things will become confusing) so I'd just recommend to use GlassFish for the deployment of your JAX-WS web services, it has everything required included ¹.

But please, forget Axis 2 and its horrible deployment model (to be honest, I don't understand why people keep mentioning Axis 2, maybe only because it has been promoted by IBM with its Eclipse support).

You'll find plenty of other resources on Glen Mazza's Weblog, for example the "famous" DoubleIt tutorial.

If you want to go further, have a loot at this great online Web Services Course from JavaPassion (great resources, as always).

¹ If really you want to know, the web services stack in GlassFish is called Metro. Metro includes JAX-WS RI (the reference implementation of JAX-WS) and WSIT (that provides an implementation of others WS-* standards for Secure, Reliable, Transactional and Interoperable Web services). Another implementation of JAX-WS is Apache CXF. You may find all these terms in the literature. For now, I'd stick with JAX-WS RI with GlassFish as container and NetBeans as IDE.

This is a must if you plan to provide (SOAP based) webservices or want to get a feeling on how to consume services: soapUI

And I am quite happy with eclipse's web tools platform when it comes to designing xml schemas and wsdl files.

One of the most common java libraries is apache axis2. Pretty sure, they have a lot of documentation and tutorials on their pages.

Just start with apache tomcat and run a web-application in it with a small servlet or JSP, and then once you master a bit how to create web applications for tomcat, go and check axis2, this is a web application that gets installed in tomcat, then you will be able to run your own web services in axis2.

If you one something more advanced you could go and check EJB3 and create a stateless session bean that will work as a web service... but this is more advanced and is much more difficult to set up an EJB3 project, I advise starting with tomcat/axis2.

good luck.