I have a problem with injecting EJB inside of a REST service (using jersey on glassfish 3.2 server) and I'm puzzled.
I have an EJB interface declared as:
import javax.ejb.Local;
#Local
public interface TestServiceLocal {
public String getText();
}
and the class bean that implements it:
import javax.ejb.Local;
import javax.ejb.Stateless;
/**
* Session Bean implementation class TestService
*/
#Stateless
#Local(TestServiceLocal.class)
public class TestService implements Serializable, TestServiceLocal {
private static final long serialVersionUID = 1L;
/**
* Default constructor.
*/
public TestService() {
// TODO Auto-generated constructor stub
}
#Override
public String getText() {
return this.getClass().getName();
}
}
The REST service looks like:
#Path("/service")
#Stateless
public class TestRestService {
#EJB(beanName="TestService")
private TestServiceLocal testService;
public TestRestService () {
}
#GET
#Produces(MediaType.TEXT_PLAIN)
#Path("/events")
public String getText() {
return testService.getText();
}
}
The problem is that when the REST service is called the bean cannot be created:
SEVERE: EJB5070: Exception creating stateless session bean : [TestRestService]
WARNING: EJB5184:A system exception occurred during an invocation on EJB TestRestService, method: public java.lang.String TestRestService.getText()
WARNING: javax.ejb.EJBException: javax.ejb.EJBException: javax.ejb.CreateException: Could not create stateless EJB
at com.sun.ejb.containers.StatelessSessionContainer._getContext(StatelessSessionContainer.java:454)
at com.sun.ejb.containers.BaseContainer.getContext(BaseContainer.java:2547)
at com.sun.ejb.containers.BaseContainer.preInvoke(BaseContainer.java:1899)
at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:212)
at com.sun.ejb.containers.EJBLocalObjectInvocationHandlerDelegate.invoke(EJBLocalObjectInvocationHandlerDelegate.java:88)
at com.sun.proxy.$Proxy839.getText(Unknown Source)
I had already took a look at the answers posted here but none of them seemed to work for me. Any help will be appreciated. Thank you!
PS: I forgot to mentioned (don't know if it's relevant). My project is created under eclipse Juno as Dynamic Web Project.
Related
After upgrading Quarkus from 1.6.1.Final to 2.5.Final the following #Inject fails inside javax.ws.rs.core.Application subclass:
#ApplicationScoped
public class MyBean {
public String foo() {
retun "bar";
}
}
#ApplicationPath("/")
public class MyApplication extends Application {
#Inject
MyBean myBean;
#Override
public Set<Class<?>> getClasses() {
myBean.foo(); // Causes NPE on Quarkus 2.5.Final, worked well with 1.6.1.Final
}
}
I tried with CDI.current().select(MyBean.class).get() but got Unable to locate CDIProvider.
Any other workaround I can try? Thanks.
#Inject in JAX-RS Application classes has been since disallowed. I was able to solve my issue (registering resource classes by config) using #IfBuildProperty annotation.
I created a project to test the dependency injection offered by Google Guice in my Jax-rs resources, using Resteasy.
My intentions are:
Use multiple #ApplicationPath for the versions of my API. In each class annotated with #ApplicationPath I load a set of classes for the specific version.
Each resource have a #Inject (from Google Guice) in his constructor to inject some services.
I created two classes annotated with #ApplicationPath: ApplicationV1RS and ApplicationV2RS. In both I added the same resources classes (UserResource and HelloResource), only for my test.
My Module is configured like this:
public class HelloModule implements Module
{
public void configure(final Binder binder)
{
binder.bind(IGreeterService.class).to(GreeterService.class);
binder.bind(IUserService.class).to(UserService.class);
}
}
When I call http://localhost:9095/v1/hello/world or http://localhost:9095/v2/hello/world, I receive the same error:
java.lang.RuntimeException: RESTEASY003190: Could not find constructor
for class: org.jboss.resteasy.examples.guice.hello.HelloResource
Well, as I expected, this not works. The Google Guice is not "smart" to instantiate the resource classes using the construtor for me.
But I can't find a way to work. To be really honest, I'm really confuse about how the Google Guice, Jetty and Resteasy play with each other in this scenario.
If I abandon the idea of use #ApplicationPath, my resources work with Google Guice configuring my HelloModule like this:
public class HelloModule implements Module
{
public void configure(final Binder binder)
{
binder.bind(HelloResource.class);
binder.bind(IGreeterService.class).to(GreeterService.class);
binder.bind(UserResource.class);
binder.bind(IUserService.class).to(UserService.class);
}
}
But in this case, I'm passing the control to register my resources (HelloResource and UserResource) to Guice. It's not flexible for me, I can't setup my multiple #ApplicationPath.
So, what I'm missing or not understanding?
I created a project with the problemetic code. Is very easy to setup and test: https://github.com/dherik/resteasy-guice-hello/tree/so-question/README.md
Thanks!
When you have getClasses method in your Application then it tries to create instance for all the registered resources using the default constructor which is missing in our Resources class. One way is to create a default constructor and Inject the dependencies through setter Injection.
And then instead of overriding getClasses in ApplicationV1RS and ApplicationV2RS you override getSingletons. Since Resources can be Singleton.
Below are the changes that I made to make it work the way you want.
ApplicationV1RS.java
#ApplicationPath("v1")
public class ApplicationV1RS extends Application {
private Set<Object> singletons = new HashSet<Object>();
public ApplicationV1RS(#Context ServletContext servletContext) {
}
#Override
public Set<Object> getSingletons() {
Injector injector = Guice.createInjector(new HelloModule());
HelloResource helloResource = injector.getInstance(HelloResource.class);
UserResource userResource = injector.getInstance(UserResource.class);
singletons.add(helloResource);
singletons.add(userResource);
return singletons;
}
}
ApplicationV2RS.java
#ApplicationPath("v2")
public class ApplicationV2RS extends Application {
private Set<Object> singletons = new HashSet<Object>();
public ApplicationV2RS(#Context ServletContext servletContext) {
}
#Override
public Set<Object> getSingletons() {
Injector injector = Guice.createInjector(new HelloModule());
HelloResource helloResource = injector.getInstance(HelloResource.class);
UserResource userResource = injector.getInstance(UserResource.class);
singletons.add(helloResource);
singletons.add(userResource);
return singletons;
}
}
HelloResource.java
#Path("hello")
public class HelloResource {
#Inject
private IGreeterService greeter;
public HelloResource() {
}
#GET
#Path("{name}")
public String hello(#PathParam("name") final String name) {
return greeter.greet(name);
}
}
UserResource.java
#Path("user")
public class UserResource {
#Inject
private IUserService userService;
public UserResource() {
}
#GET
#Path("{name}")
public String hello(#PathParam("name") final String name) {
return userService.getUser(name);
}
}
Add #Singleton to your Service Classes.
Hope it helps.
I have also pushed the code to forked repo. check it out
i have created sigleton session bean which keeps one connection to my mongo database. It works well in jax-rs class when using #EJB annotation - after controller is contructed and bean is injected it calls init method anotated with #PostConstruct.
Then i created similar class, which is implementing SecurityContext. I used same pattern as in controller, but it is not working properly. init() method is never called and EJB instance is always null.
So is there a way to inject EJB to my SecurityContext implemetation ? it works well unless i try to inject and use MongoConnection
my singleton session bean I use to connect mongo database:
#Singleton
#Startup
public class MongoConnection {
#PostConstruct
public void init() {
// initialize properties
}
I use it in JAX-RS controller. it works here, also in classes inherited from EntityController.
Produces(MediaType.APPLICATION_JSON)
public class EntityController extends Application {
#Context
private UriInfo context;
**#EJB
protected MongoConnection connection;**
public EntityController() {
#PostConstruct
void init() {
...
connection.getMongo();
connection.getDatabaseName();
...
}
}
I implemented my own security context, which is looking for loged user roles in mongo database.
public class MongoSecurityContext implements SecurityContext {
**#EJB
private MongoConnection connection;**
public MongoSecurityContext() {
}
#PostConstruct
void init() {
...
connection.getMongo();
connection.getDatabaseName();
...
}
public MongoSecurityContext(ContainerRequestContext requestContext) {
token = requestContext.getHeaderString("token");
}
#Override
public boolean isUserInRole(String roleName) {
//**connection is allways null**, so it returns false;
if (connection == null)
return false;
}
}
EDIT:
I forget, i also have this warning in glassfish 4 console:
A provider extremeteacher.mongo.connection.MongoConnectionEjb registered in SERVER runtime does not implement any provider interfaces applicable in the SERVER runtime. Due to constraint configuration problems the provider extremeteacher.mongo.connection.MongoConnectionEjb will be ignored
EDIT2:
#Provider
#Priority(Priorities.AUTHORIZATION)
public class AuthorizationFilter implements ContainerRequestFilter {
#Override
public void filter(ContainerRequestContext requestContext) {
requestContext.setSecurityContext(new MongoSecurityContext(requestContext)) ;
}
}
Injection does not work for objects created with new because the container is never given control to perform the injection. I recommend moving the #EJB to the filter and passing it to the MongoSecurityContext constructor.
I am creating a RESTful Web Service that wraps an antiquated vendor API. Some external configuration will be required and will be stored on the server either in a file or rdbms. I'm using Jersey 1.11.1 in Glassfish 3.1.2. This configuration data is all in String key/value format.
My first question is this - where can I store global/instance variables in Jersey so that they will be persisted between requests and available to all resources? If this was a pure Servlet application I would use the ServletContext to accomplish this.
The second part to the question is how can I load my configuration once the Jersey server has loaded? Again, my Servlet analogy would be to find the equivalent to the init() method.
#Singleton #Startup EJB matches your requirements.
#Singleton
#Startup // initialize at deployment time instead of first invocation
public class VendorConfiguration {
#PostConstruct
void loadConfiguration() {
// do the startup initialization here
}
#Lock(LockType.READ) // To allow multiple threads to invoke this method
// simultaneusly
public String getValue(String key) {
}
}
#Path('/resource')
#Stateless
public class TheResource {
#EJB
VendorConfiguration configuration;
// ...
}
EDIT: Added annotation as per Graham's comment
You can use a listener for init the variables and set to the context as attribute before the web application start, something like the following:
package org.paulvargas.shared;
import java.util.HashMap;
import java.util.Map;
import javax.servlet.ServletContext;
import javax.servlet.ServletContextEvent;
import javax.servlet.ServletContextListener;
public class LoadConfigurationListener implements ServletContextListener {
public void contextInitialized(ServletContextEvent sce) {
// read file or rdbms
...
ServletContext context = sce.getServletContext();
// set attributes
...
}
public void contextDestroyed(ServletContextEvent sce) {
ServletContext context = sce.getServletContext();
// remove attributes
...
}
}
This listener is configured in the web.xml.
<listener>
<listener-class>org.paulvargas.shared.LoadConfigurationListener</listener-class>
</listener>
You can use the #Context annotation for inject the ServletContext and retrieving the attribute.
package org.paulvargas.example.helloworld;
import java.util.*;
import javax.servlet.ServletContext;
import javax.ws.rs.*;
import javax.ws.rs.core.*;
#Path("/world")
public class HelloWorld {
#Context
private ServletContext context;
#GET
#Produces("text/plain; charset=UTF-8")
public String getGreeting() {
// get attributes
String someVar = (String) context.getAttribute("someName")
return someVar + " says hello!";
}
}
Here is my bean that is trying to inject a singleton bean InformationService :
#Path("/information/{name}")
#Stateless (name="InformationResource")
public class InformationResource {
#EJB
private InformationService appService;
#GET
#Produces(MediaType.APPLICATION_XML)
public Information getInfo(#PathParam("name") String name){
return appService.getMap().get(name);
}
#PUT
#POST
#Consumes(MediaType.APPLICATION_XML)
public Information putInfo(#PathParam("name") String name, Information info){
return appService.getMap().put(name,info);
}
#DELETE
public void deleteInfo(#PathParam("name") String name){
appService.getMap().remove(name);
}
}
This is the InformationService class
#Singleton
public class InformationService {
private Map<String,Information> map;
#PostConstruct
public void init(){
map = new HashMap<String,Information>();
map.put("daud", new Information("B.Tech","Lucknow"));
map.put("anuragh", new Information("M.Sc","Delhi"));
}
public Map<String,Information> getMap(){
return map;
}
}
Its part of a very simple JAX-RS implementation and I am deploying as war in JBoss 6.1 Final. The problem is that InformationService throwing a NullPointerException when I make the proper get request. If I initialize appService explicitly, everything works fine. Why is #EJB annotation not working ?
Are you using Jersey as REST implementation? If so, EJB injection is not supported out of the box.
This link provides more information on this and also a solution.
Check that your #Singleton is javax.ejb.Singleton.
Any other exceptions before NPE ?