JAX-RS response with HTTP status 500 instead of HTTP status 400

Question

Sometimes JAR-RS clients are sending wrong syntactical request body. The server should response with HTTP status 400 (Bad Request), but it responses with HTTP status 500 (Internal Server Error).

Code:

JAX-B model class:

@XmlRootElement(namespace = "http://www.test.com/test")
@XmlAccessorType(value = XmlAccessType.FIELD)
public class TestModel {

    @XmlElement
    private String id;
}

JAX-RS resource class:

@Path("test")
public class TestResource {

    @POST
    @Consumes(MediaType.APPLICATION_JSON)
    public void create(TestModel testModel) {
        // some code
    }
}

CXF configuration:

<jaxrs:server address="/rest" id="test" staticSubresourceResolution="true">
    <jaxrs:serviceBeans>
        <ref bean="testResource" /> 
    </jaxrs:serviceBeans>
    <jaxrs:providers>
        <bean class="com.fasterxml.jackson.jaxrs.json.JacksonJaxbJsonProvider" />
    </jaxrs:providers>
</jaxrs:server>

Example:

Request body:

{"id2": "test"}

The id2 is wrong, so client should get a HTTP status 400, but it gets HTTP status 500.

Server log:

Caused by: com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException: Unrecognized field "id2" (class test.TestModel), not marked as ignorable (one known property: "id"])
    at [Source: org.apache.cxf.transport.http.AbstractHTTPDestination$1@6f30793d; line: 1, column: 10] (through reference chain: test.TestModel["id2"])
    at com.fasterxml.jackson.databind.exc.UnrecognizedPropertyException.from(UnrecognizedPropertyException.java:51)
    at com.fasterxml.jackson.databind.DeserializationContext.reportUnknownProperty(DeserializationContext.java:839)
    at com.fasterxml.jackson.databind.deser.std.StdDeserializer.handleUnknownProperty(StdDeserializer.java:1045)
    at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownProperty(BeanDeserializerBase.java:1352)
    at com.fasterxml.jackson.databind.deser.BeanDeserializerBase.handleUnknownVanilla(BeanDeserializerBase.java:1330)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.vanillaDeserialize(BeanDeserializer.java:264)
    at com.fasterxml.jackson.databind.deser.BeanDeserializer.deserialize(BeanDeserializer.java:125)
    at com.fasterxml.jackson.databind.ObjectReader._bind(ObjectReader.java:1470)
    at com.fasterxml.jackson.databind.ObjectReader.readValue(ObjectReader.java:912)
    at com.fasterxml.jackson.jaxrs.base.ProviderBase.readFrom(ProviderBase.java:811)
    at org.apache.cxf.jaxrs.utils.JAXRSUtils.readFromMessageBodyReader(JAXRSUtils.java:1343)
    at org.apache.cxf.jaxrs.utils.JAXRSUtils.readFromMessageBody(JAXRSUtils.java:1294)
    at org.apache.cxf.jaxrs.utils.JAXRSUtils.processParameter(JAXRSUtils.java:826)
    at org.apache.cxf.jaxrs.utils.JAXRSUtils.processParameters(JAXRSUtils.java:789)
    at org.apache.cxf.jaxrs.interceptor.JAXRSInInterceptor.processRequest(JAXRSInInterceptor.java:212)
    ... 68 more

Is there a way to configure Jackson and/or CXF to return HTTP status 400 for wrong syntactical request body without schema validation or bean validation?

Answer 1

The problem is that exceptions that aren't mapped to response (by way of ExceptionMappers), translate to a general server error response, as the runtime has no idea what to do with the exception.

The jackson-jaxrs-provider module has ExceptionMappers to handle the Jackson base exception class JsonMappingException and JsonParseException. The mappers are JsonMappingExceptionMapper and JsonParseExceptionMapper, respectively. These mappers will map the exception to a 400 response along with the exception message as the response body. If you do not like this response body, you can just write your own mapper.