Welcome to JAX-WS Tutorial. Web Services work on client-server model where they communicate over the network. Server side component provides the endpoint URL where service is located and client application can invoke different methods.

There are two types of web services:

  1. SOAP Web Services
  2. Restful Web Services

JAX-WS Tutorial

In this JAX-WS tutorial, we will use JAX-WS to create SOAP based web services. But first we will go through some of the jargon words used in SOAP web services.

SOAP

SOAP stands for Simple Object Access Protocol. SOAP is an XML based industry standard protocol for designing and developing web services. Since it’s XML based, it’s platform and language independent. So our server can be based on JAVA and client can be on .NET, PHP etc. and vice versa.

WSDL

WSDL stands for Web Service Description Language. WSDL is an XML based document that provides technical details about the web service. Some of the useful information in WSDL document are: method name, port types, service end point, binding, method parameters etc.

UDDI

UDDI is acronym for Universal Description, Discovery and Integration. UDDI is a directory of web services where client applications can lookup for web services. Web Services can register to the UDDI server and make them available to client applications.

Advantages of Web Services

Some of the advantages of web services are:

  • Interoperability: Because web services work over network and use XML technology to communicate, it can be developed in any programming language supporting web services development.
  • Reusability: One web service can be used by many client applications at the same time. For example, we can expose a web service for technical analysis of a stock and it can be used by all the banks and financial institutions.
  • Loose Coupling: Web services client code is totally independent with server code, so we have achieved loose coupling in our application. This leads to easy maintenance and easy to extend.
  • Easy to deploy and integrate
  • Multiple service versions can be running at same time.

JAX-WS

JAX-WS stands for Java API for XML Web Services. JAX-WS is XML based Java API to build web services server and client application. It’s part of standard Java API, so we don’t need to include anything else which working with it.

JAX-WS Example

Now that we have gone through the web services terminologies, let’s go ahead and create a JAX-WS web service. We will create a web service that will expose methods to add, delete and get person objects. So first of all we will create a model bean for our data.

Person.java

Now we will have to create an interface where we will declare the methods we will expose in our JAX-WS example web services.

PersonService.java

Notice the use of @WebService and @SOAPBinding annotations from JAX-WS API. We can create SOAP web services in RPC style or Document style. We can use any of these styles to create web services, the different is seen in the way WSDL file is generated.

Now we will write the implementation class as shown below.

PersonServiceImpl.java

Most important part is the @WebService annotation where we are providing endpointInterface value as the interface we have for our web service. This way JAX-WS know the class to use for implementation when web service methods are invoked.

Our web service business logic is ready, let’s go ahead and publish it using JAX-WS Endpoint class.

SOAPPublisher.java

Just run the above program and your web service will be published at the given endpoint in the program. We can access it’s WSDL document by adding ?wsdl to the endpoint url as shown in below image.

wsimport-utility-parse-wsdl

Here is the WSDL code, we will use some of the values from these while writing the client code.

person.wsdl

Here is a client program where we are invoking our JAX-WS example web service.

SOAPPublisherClient.java

When we execute above JAX-WS client program, we get this output.

When I run the program again, we get this output.

Notice that in the second run, add person status is false because it was already added in the first run.

JAX-WS Client Program

If you look at the above program, we are using the server code itself. However web services just expose WSDL and third party applications don’t have access to these classes. So in that case, we can use wsimport utility to generate the client stubs. This utility comes with standard installation of JDK. Below image shows what all java classes we get when we run this utility.

wsimport-utility-parse-wsdl-

Just copy these classes into your client project, the only change would be the way we get PersonService instance.

Below is the program for this, the output will be same as above client program. Notice the use of PersonServiceImplService class and it’s method getPersonServiceImplPort to get the PersonService instance.

TestPersonService.java

That’s all for a quick JAX-WS tutorial.

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