Use XML content in JAX-RS application requests and responses

XML is a common media format that RESTful services consume and produce. To deserialize and serialize XML, we can represent requests and responses by Java Architecture for XML Binding (JAXB) annotated objects.

JAXB a Java technology that provides an easy and convenient way to map Java classes and an XML schema for simplified development of web services. JAXB uses the flexibility of platform-neutral XML data in Java applications to bind an XML schema to Java applications without requiring extensive knowledge of XML programming.

This task describes how to use JAXB to deserialize and serialize XML content.

Tasks

1. Configure the development environment.

   1. Before starting developing JAX-RS applications, we must set up the development environment by adding the JAX-RS libraries on the classpath.

2. Define the resources in JAX-RS web applications.
   1. Resources are the basic building block of a RESTful service. Resources can contain static or dynamically updated data. Examples of resources from an online book store application include a book, an order from a store, and a collection of users. By identifying the resources in the application, we can make the service more useful and easier to develop.

3. Configure the JAX-RS application.

   We can configure JAX-RS applications in multiple . To take advantage of the Java EE 6 functionality, we can use the annotation scanning capabilities. By using annotation scanning, we can omit a JAX-RS javax.ws.rs.core.Application subclass or have a minimally defined javax.ws.rs.core.Application subclass. Alternatively, we can specify the IBM JAX-RS servlet or filter to use the functionality available in the IBM JAX-RS servlet and filter.

   Using one of the JAX-RS Version 1.1 configuration methods, we can omit a javax.ws.rs.core.Application subclass in the application or have a javax.ws.rs.core.Application subclass that returns an empty set of classes to inform the JAX-RS runtime environment to find and use all the JAX-RS classes in the application. We might want to use this method when we do not want to have to manually add every relevant JAX-RS class to a javax.ws.rs.core.Application subclass as you develop the application.

   By specifying the specific IBM JAX-RS servlet and filter, we can take advantage of and ensure specific IBM JAX-RS behavior. For example, using the IBM JAX-RS filter can be helpful in developing a web application with a mix of JAX-RS resources and JSP files with the same URL patterns.

   Even though there is a JAX-RS V1.1 configuration method that supports the use of an optional web.xml file, to specify security constraints or roles, or we want to take advantage of other features enabled using a web.xml file, specify the information in a web.xml file.

   Choose one of the following three methods to configure the JAX-RS application:

   • Configure JAX-RS applications using JAX-RS 1.1 methods

     Use this method to use the annotation scanning capabilities or to use the JAX-RS 1.1 configuration methods. Use the annotation scanning capabilities to promote application portability, to minimize the amount of configuration code, or to dynamically modify the application without changes to the application code.

   • Configure the web.xml file for JAX-RS servlets

     Use this method to specify features enabled using servlet initialization parameters to change the behavior and ensure that we get the IBM JAX-RS servlet. When using servlets, we can define a servlet path in the web.xml file that is appended to the base URL.

   • Configure the web.xml file for JAX-RS filters

     Use this method to use the filter when we have JSPs, other servlets and filters, and JAX-RS resources with a mix of URL patterns. We can configure the web.xml file to define filters that indicate the possible URLs on which the filter can be invoked.

4. Implement a resource method using JAXB objects for XML content.

   1. Use JAXB objects as request entity parameters and response entities with JAX-RS applications. Instead of transforming XML to and from native Java types, we can take advantage of using JAXB objects.

5. Assemble JAX-RS web applications.

   1. After developing the Java class files for our JAX-RS web application and edit the web.xml file to enable the JAX-RS servlet, we are ready to assemble the application. Assemble the web application into a web application archive (WAR) package. We can assemble the WAR package into an enterprise archive (EAR) package, if required.

6. Deploy JAX-RS web applications.

   1. After assembling the JAX-RS web application, we need to deploy your Web archive (WAR) package or the EAR package onto the application server.

We have developed and deployed a JAX-RS web application on the application server that uses XML content for requests and responses.

Implement a resource method using JAXB objects for XML content

Web services specifications and APIs