I'm having a small problem when trying to use Guice with ContainerRequestFilter, it throws a NullPointerException. I did a little digging into RESTEasy and it would appear that it can't find a constructor for MyFilter due to the @Context annotation not being present, the NullPointerException is thrown when trying to instantiate a null constructor.
My filter:
@Provider @PreMatching public class MyFilter implements ContainerRequestFilter { private Dependency d; @Inject public MyFilter(Dependency d) { this.d = d; } @Override public void filter(ContainerRequestContext containerRequestContext) throws IOException { if (d.doSomething()) { Response r = Response.status(Response.Status.INTERNAL_SERVER_ERROR).build(); containerRequestContext.abortWith(r); } } } I've added the filter to my Application class:
@ApplicationPath("") public class Main extends Application { private Set<Object> singletons = new HashSet<Object>(); private Set<Class<?>> c = new HashSet<Class<?>>(); public Main() { c.add(Dependency.class); } @Override public Set<Class<?>> getClasses() { return c; } @Override public Set<Object> getSingletons() { return singletons; } } My Guice configuration:
public class GuiceConfigurator implements Module { public void configure(final Binder binder) { binder.bind(Dependency.class); } } My web.xml:
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1"> <display-name>My App</display-name> <context-param> <param-name>resteasy.guice.modules</param-name> <param-value>com.example.GuiceConfigurator</param-value> </context-param> <listener> <listener-class> org.jboss.resteasy.plugins.guice.GuiceResteasyBootstrapServletContextListener </listener-class> </listener> </web-app> This configuration is working for injecting my dependencies into resources, but I get a NullPointerException when trying to use it on a provider.
Any help would be appreciated.
1 Answers
Answers 1
It seems that even with RESTeasy/JAX-RS components, you still need to register it with the Guice binder. I wasn't sure at first, but looking at the test cases, it seems we still need to register our resources and providers with Guice to make it work.
I test it after adding the filter to the Guice module, and it works as expected.
public class GuiceConfigurator implements Module { public void configure(final Binder binder) { binder.bind(MyFilter.class); binder.bind(Dependency.class); } } To test, I went off the example from the RESTeasy project, added a filter with the constructor injection, and added the filter to the module binder. And it worked when adding the filter to the module and failed when not added.
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