Implementing Rest Easy with Tomcat - rest

Question

I have a Dynamic Web Project with a set of jsp's and a custom controller servlet, that is working great. But, I also need to implement a rest easy exposed service on it, and that's why i changed the web. xml to contain rest easy servlet also. and the application class which invokes the rest easy resource. But, when i am adding changes to web.xml, it is hitting rest easy servlet, but throwing exception..
java.lang.ClassNotFoundException: org.scannotation.AnnotationDB$CrossReferenceException
Web.xml :
<servlet>
<display-name>ControllerServlet</display-name>
<servlet-name>ControllerServlet</servlet-name>
<servlet-class>com.example.ControllerServlet</servlet-class>
<load-on-startup>1</load-on-startup>
</servlet>
<servlet>
<servlet-name>CollRestApi</servlet-name>
<servlet-class>org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher</servlet-class>
<init-param>
<param-name>javax.ws.rs.Application</param-name>
<param-value>com.exampl.RestApiApplication</param-value>
</init-param>
</servlet>
<servlet-mapping>
<servlet-name>ControllerServlet</servlet-name>
<url-pattern>/ControllerServlet</url-pattern>
</servlet-mapping>
<servlet-mapping>
<servlet-name>CollRestApi</servlet-name>
<url-pattern>/or/*</url-pattern>
</servlet-mapping>
Rest Api Application :
public class RestApiApplication extends Application{
private Set<Object> singletons = new HashSet();
private Set<Class<?>> empty = new HashSet();
public RestApiApplication() {
// ADD YOUR RESTFUL RESOURCES HERE
this.singletons.add(new CollRestApi());
}
public Set<Class<?>> getClasses()
{
return this.empty;
}
public Set<Object> getSingletons()
{
return this.singletons;
}}
And CollRestApi.. is having exposed services..
#Path("api")#Consumes({ "application/xml", "application/json" })#Produces({application/xml", "application/json" })public class CollRestApi {
/**
* #return
*/
#GET
#Path("ab")
public Response do() {
System.out.println("Inside the do Method.");
}}

Answer 1

Obviously, you need to add scannotation.jar to your classpath. RESTEasy 2.2.2.GA depends on scannotation-1.0.3 and javassist-3.12.1.GA.jar which you also need.

Answer 2

I just faced the same problem using maven and netbeans. The answer is to add the jboss maven repository to your pom.xml-file. Just adding <dependency>....</dependency>, e.g. by using netbeans maven browser, doesn't install the dependecies of resteasy.
<repositories>
<repository>
<id>jboss</id>
<url>http://repository.jboss.org/nexus/content/groups/public-jboss/</url>
</repository>
</repositories>

Answer 3

I had the same exception, and fixed it like this:
Is it possible you have the resteasy**.jar libraries in a different location (e.g. the tomcat lib dir) than other resteasy-supporting libs like scannotation-1.0.3.jar (e.g. in your war file WEB-INF/lib) ?
In such a configuration your resteasy classes will start in a different classloader which does not see the scannotation-1.0.3.jar classes.
=> Try putting all resteasy jar files in either one of the locations (preferably your .war file).