如何让 Wildfly 10 / Resteasy 向客户端指示序列化异常

Question

当在 Wildfly 10 中对 jax-rs 响应进行 json 序列化期间发生异常时，将提交响应并且无法再更改 HTTP return 代码。在服务器端记录了一个异常：

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[=10=]0(ServletInitialHandler.java:81)
    at io.undertow.servlet.handlers.ServletInitialHandler.handleRequest(ServletInitialHandler.java:174)
    at io.undertow.server.Connectors.executeRootHandler(Connectors.java:202)
    at io.undertow.server.HttpServerExchange.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)

此外，json 序列化程序很好地关闭了所有打开的标签，因此对于客户端，响应是具有有效 json 的 http 代码 200。没有任何故障迹象，只是缺少数据。

我如何说服 Wildfly / Resteasy / Undertow 在发生异常时停止向客户端提供完全有效的响应。 500 响应或不关闭 json 都可以。

在我的测试过程中，我发现抛出异常时实际上并没有向客户端发送任何数据，响应中仍然添加了一个Content-Length header。这可能会留下更改响应代码的机会，但是我无法找到发生这种情况的位置或为什么在尚未发送任何内容时将响应标记为已提交。

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"}

测试用例

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"));
    }
}

Answer 1

您是否考虑过返回 Response 对象？这将同时具有状态和结果。客户端在获取结果前会检查状态，如果状态良好：

/**
 * Creates a new contact from the values provided and will return a JAX-RS response with either 200 ok, or 400 (BAD REQUEST)
 * in case of errors.
 */
@POST
@Consumes(MediaType.APPLICATION_JSON)
@Produces(MediaType.APPLICATION_JSON)
public Response createContact(Contact contact) {

    Response.ResponseBuilder builder = null;
    Long nextId = contactsRepository.keySet().size() + 1L;
    try {
        // Store the contact
        contact.setId(nextId);
        contactsRepository.put(nextId, contact);

        // Create an "ok" response with the persisted contact
        builder = Response.ok(contact);
    } catch (Exception e) {
        // Handle generic exceptions
        builder = Response.status(Response.Status.BAD_REQUEST).entity(e.getMessage());
    }

    return builder.build();
}

客户会这样使用它：

    // 1 - drop all contacts
    log.info("dropping all contacts");
    Response response = ClientBuilder.newClient().target(REST_TARGET_URL).request().delete();
    Assert.assertEquals("All contacts should be dropped", Response.ok().build().getStatus(), response.getStatus());

    // 2 - Create a new contact
    log.info("creating a new contact");
    Contact c = new Contact();
    c.setName(CONTACT_NAME);
    c.setPhoneNumber(CONTACT_PHONE);
    Contact persistedContact = ClientBuilder.newClient().target(REST_TARGET_URL).request().post(Entity.entity(c, MediaType.APPLICATION_JSON), Contact.class);
    Assert.assertEquals("A book should be persisted with Id=1!", (Long) 1L, (Long) persistedContact.getId());

这来自 WildFly 快速入门原型：

jaxrs-client: JAX-RS Client API example

Answer 2

我们找到了实现这一目标的方法。

在大多数情况下，禁用 AUTO_CLOSE_TARGET 将导致失败时出现 http 500 错误。我发现的唯一例外是当响应超过特定大小时，在这种情况下，某些东西将开始刷新输出。对于这种情况，禁用 AUTO_CLOSE_JSON_CONTENT 将确保 json 文档在错误时未正确关闭。

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;
    }
}

如何让 Wildfly 10 / Resteasy 向客户端指示序列化异常

How do I make Wildfly 10 / Resteasy indicate a serialization exception to the client

jakarta-ee

resteasy

undertow

wildfly-10

测试用例