When an exception occurs during json serialization of a jax-rs response in Wildfly 10 the response is committed and the HTTP return code cannot be changed anymore. An exception of this is logged on the server side:
10:19:56,148 ERROR [io.undertow.request] (default task-21) UT005023: Exception handling request to /ca00cefe-efd8-496c-a874-de0af20cad42/rest/: org.jboss.resteasy.spi.UnhandledException: RESTEASY003770: Response is committed, can't handle exception
at org.jboss.resteasy.core.SynchronousDispatcher.writeException(SynchronousDispatcher.java:167)
at org.jboss.resteasy.core.SynchronousDispatcher.writeResponse(SynchronousDispatcher.java:471)
at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:415)
at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:202)
at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:221)
at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:56)
at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:51)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:85)
at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)
at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131)
at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46)
at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64)
at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60)
at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77)
at io.undertow.security.handlers.NotificationReceiverHandler.handleRequest(NotificationReceiverHandler.java:50)
at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:284)
at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:263)
at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:81)
at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:174)
at io.undertow.server.Connectors.executeRootHandler(Connectors.java:202)
at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:793)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at java.lang.Thread.run(Thread.java:745)
Also the json serializer nicely closes all open tags, so for the client the response is http code 200 with valid json. No indication of a failure whatsoever, only missing data.
How can I convince Wildfly / Resteasy / Undertow stop giving completely valid responses to the client when an exception occurs. Either a 500 response or not closing the json would be fine.
During my testing I found that when the exception is thrown no data has actually been send to the client, a Content-Length header is still added to the response. This might leave an opportunity to change the response code, however I was unable to find where this happens or why the reponse is marked as committed when nothing has been send yet.
HTTP/1.1 200 OK
Connection: keep-alive
X-Powered-By: Undertow/1
Server: WildFly/10
Content-Type: application/json
Content-Length: 10
Date: Wed, 23 Mar 2016 09:37:19 GMT
{"a":"ok"}
TestActivator.java
package test;
import javax.ws.rs.ApplicationPath;
import javax.ws.rs.core.Application;
@ApplicationPath("/rest")
public class TestActivator extends Application {
}
TestResource.java
package test;
import java.io.Serializable;
import javax.ws.rs.GET;
import javax.ws.rs.Path;
import javax.ws.rs.Produces;
import javax.ws.rs.core.MediaType;
import javax.xml.bind.annotation.XmlRootElement;
@Path("/")
public class TestResource {
@GET
@Produces(MediaType.APPLICATION_JSON)
public TestObject test() {
return new TestObject();
}
@XmlRootElement
public class TestObject implements Serializable {
private static final long serialVersionUID = 1L;
public TestObject() {
}
public String getA() {
return "ok";
}
public String getB() {
throw new RuntimeException("error");
}
}
}
TestCase.java
package test;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
import javax.ws.rs.client.WebTarget;
import javax.ws.rs.core.Response;
import org.jboss.arquillian.container.test.api.Deployment;
import org.jboss.arquillian.extension.rest.client.ArquillianResteasyResource;
import org.jboss.arquillian.junit.Arquillian;
import org.jboss.shrinkwrap.api.ShrinkWrap;
import org.jboss.shrinkwrap.api.spec.WebArchive;
import org.json.JSONObject;
import org.json.JSONTokener;
import org.junit.Test;
import org.junit.runner.RunWith;
@RunWith(Arquillian.class)
public class TestCase {
@Deployment(testable = false)
public static WebArchive createTestArchive() {
return ShrinkWrap.create(WebArchive.class)
.addPackage(TestResource.class.getPackage());
}
/**
* This test should fail, either the response should not be 200 or a json exception should occur
*/
@Test
public void test(@ArquillianResteasyResource WebTarget webTarget) {
Response response = webTarget.path("/").request().get();
assertEquals(200, response.getStatus());
JSONObject object = new JSONObject(new JSONTokener(response.readEntity(String.class)));
assertEquals("ok", object.get("a"));
assertTrue(object.isNull("b"));
}
}
We figured out a way to achieve this.
Disabling AUTO_CLOSE_TARGET will result in a http 500 error on failure in most cases. Only exception I found is when a response exceeds a certain size, in that case something will start flushing the output. For that situation disabling AUTO_CLOSE_JSON_CONTENT will make sure the json document is not correctly closed on error.
package test;
import javax.ws.rs.ext.ContextResolver;
import javax.ws.rs.ext.Provider;
import com.fasterxml.jackson.core.JsonGenerator;
import com.fasterxml.jackson.databind.ObjectMapper;
@Provider
public class MyObjectContextResolver implements ContextResolver<ObjectMapper> {
private ObjectMapper objectMapper;
public MyObjectContextResolver() {
objectMapper = new ObjectMapper();
objectMapper.configure(JsonGenerator.Feature.AUTO_CLOSE_TARGET, false);
objectMapper.configure(JsonGenerator.Feature.AUTO_CLOSE_JSON_CONTENT, false);
}
@Override
public ObjectMapper getContext(final Class<?> arg0) {
return objectMapper;
}
}