I am adding JSONP support to a REST Service in SPRING4 + JDK 8 + STS 3.6.4
Versions:
Spring 4.1.6.RELEASE
My implementation is based on these links:
http://docs.spring.io/spring/docs/current/spring-framework-reference/htmlsingle/#mvc-ann-jsonp
The REST service returns ResponseEntity or ResponseBody and use case is to return data in JSONP format.
Added a ControllerAdvice
#ControllerAdvice
public class JsonpCallbackAdvice extends AbstractJsonpResponseBodyAdvice {
public JsonpCallbackAdvice(){
super("Callback");
}
}
Here is the Controller of the REST Service
#Controller
public class AcctController {
...
#RequestMapping(value = "/act/{actNum}", method = RequestMethod.GET)
public ResponseEntity<Account> getAccount(#PathVariable("actNum") Integer accountNum) throws Exception {
...
return new ResponseEntity<account>();
}
Here is the relevant web application context configuration
...
<context:component-scan base-package="com.controllers" />
<bean name="jsonMessageConverter"
class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter" />
...
The controller and ControllerAdvice are in same package.
When deployment of the project is initiated following exception is observed
Caused by: java.lang.ClassCastException: [Ljava.lang.String; cannot be cast to java.lang.String
at org.springframework.context.annotation.AnnotationBeanNameGenerator.determineBeanNameFromAnnotation(AnnotationBeanNameGenerator.java:91)
at org.springframework.context.annotation.AnnotationBeanNameGenerator.generateBeanName(AnnotationBeanNameGenerator.java:69)
at org.springframework.context.annotation.ClassPathBeanDefinitionScanner.doScan(ClassPathBeanDefinitionScanner.java:246)
at org.springframework.context.annotation.ComponentScanBeanDefinitionParser.parse(ComponentScanBeanDefinitionParser.java:84)
at org.springframework.beans.factory.xml.NamespaceHandlerSupport.parse(NamespaceHandlerSupport.java:74)
at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parseCustomElement(BeanDefinitionParserDelegate.java:1427)
at org.springframework.beans.factory.xml.BeanDefinitionParserDelegate.parseCustomElement(BeanDefinitionParserDelegate.java:1417)
at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.parseBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:174)
at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.doRegisterBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:144)
at org.springframework.beans.factory.xml.DefaultBeanDefinitionDocumentReader.registerBeanDefinitions(DefaultBeanDefinitionDocumentReader.java:100)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.registerBeanDefinitions(XmlBeanDefinitionReader.java:510)
at org.springframework.beans.factory.xml.XmlBeanDefinitionReader.doLoadBeanDefinitions(XmlBeanDefinitionReader.java:392)
This exception was not happening before the ControllerAdvice was added.
Also, it does not happens when #ControllerAdvice annotation is removed
or
the component scan excludes scanning package of the ControllerAdvice class
I tried with Spring version 4.2.0.RC1, and the exception still happens.
Kindly help with resolution of this exception, since not much help is available online.
It seems like a bug in SPRING 4, however am not sure.
Related
I have the following resource that consumes a JSON being mapped to a POJO.
#Path("example")
public class ExampleResource {
#POST
#Consumes(MediaType.APPLICATION_JSON)
public Response addThesis(MyObject myObject) {
return Response.ok().entity("Test").build();
}
}
Here's the POJO class:
public class MyObject {
private String title;
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
}
When I send a POST request with the body {"title":"Test title"} everything works fine. The response is Test, as expected. However, when I change the request to {"titlee":"Test title"} the server replies with this:
Unrecognized field "titlee" (class com.my.package.MyObject), not marked as ignorable (one known property: "title"])
at [Source: org.glassfish.jersey.message.internal.ReaderInterceptorExecutor$UnCloseableInputStream#6dc6a46a; line: 2, column: 11] (through reference chain: com.my.package.MyObject["titlee"])
Obviously this is an exception thrown and returned by Jersey. How can I intercept this exception and return a custom status code and message?
What I've tried so far is to implement my own ExceptionMapper:
#Provider
public class MyJsonExceptionMapper implements ExceptionMapper<JsonProcessingException> {
public Response toResponse(JsonProcessingException e) {
return Response.status(400).entity("JSON Processing Error").build();
}
}
Unfortunately the response stays the same. When I implement an ExceptionMapper for a custom exception and throw the corresponding exception in the resource method though, everything works fine. I assume this has to do with the default ExceptionMapper for JsonProcessingException overriding my own one. Then I tried to create a generic mapper ("implements ExceptionMapper"), but again no success.
I've looked literally everywhere and tried many things including extending ResourceConfig and registering my mapper, but nothing has worked so far.
Some more information that might help to narrow the problem down: I am using Grizzly2 as the HTTP server which I am deploying as a Fat JAR.
The dependency part of my pom.xml looks like this:
<dependencies>
<dependency>
<groupId>org.glassfish.jersey.media</groupId>
<artifactId>jersey-media-json-jackson</artifactId>
<version>2.24</version>
</dependency>
<dependency>
<groupId>org.glassfish.jersey.containers</groupId>
<artifactId>jersey-container-grizzly2-http</artifactId>
<version>2.24</version>
</dependency>
</dependencies>
Any advice is highly appreciated.
Ok, this is dumb and hack-ish, but worked for me:
register(JacksonJaxbJsonProvider.class);
This is due to the following "nice default behavior" in the Jackson feature entry point:
if (!config.isRegistered(JacksonJaxbJsonProvider.class)) {
// add the default Jackson exception mappers
context.register(JsonParseExceptionMapper.class);
context.register(JsonMappingExceptionMapper.class);
:(
But, I'd still prefer an answer that fixes the problem "for real" - ie. without pre-registering components so that the feature cannot configure them properly...
I also faced this issue. If JacksonFeature is registered, you can simply register JacksonJaxbJsonProvider as a workaround.
When the JacksonFeature is in the classpath, it is automatically discovered by Jersey. Another approach to fix it is disabling auto discovery by setting ServerProperties.FEATURE_AUTO_DISCOVERY_DISABLE to true. As a result of this, you would need to register other features manually.
Alternatively you can get rid of the jersey-media-json-jackson artifact and use jackson-jaxrs-json-provider instead. With this, you will get rid of JacksonFeature and then you can register your own exception mappers.
One last option and probably what seems to be the correct solution (as pointed in Kysil Ivan's answer) you can write your own exception mapper and then give it a high priority, such as 1. If you use auto discovery, just annotate it with #Provider and #Priority:
#Provider
#Priority(1)
public class JsonParseExceptionMapper implements ExceptionMapper<JsonParseException> {
...
}
If you manually register your provider, you can give your provider a binding priority:
#ApplicationPath("/")
public class MyResourceConfig extends ResourceConfig {
public MyResourceConfig() {
register(JsonParseExceptionMapper.class, 1);
}
}
See this answer for more details.
We use JAX-RS on Wildfly to implement our web services and use the following to accomplish what you are trying to do with Jersey on Glassfish. Maybe it has similar features which you could look up. Our steps are:
The service is a stateless EJB, use EJB interceptor to trap exception
and populate request scoped object with details
Implement a PostProcessInterceptor which reads from request scoped object and modifies response before service returns. (This is specific to JAX-RS)
For my REST api I'm using jersey and ExceptionMapper to catch global exceptions.
It works well all the exception my app throws but I'm unable to catch exception thrown by jackson.
For example one of my endpoint accept an object that contains an enum. If the Json in the request has a value that is not in the enum jersey throw this exception back
Can not construct instance of my.package.MyEnum from String value 'HELLO': value not one of declared Enum instance names: [TEST, TEST2]
at [Source: org.glassfish.jersey.message.internal.ReaderInterceptorExecutor$UnCloseableInputStream#5922e236; line: 3, column: 1] (through reference chain: java.util.HashSet[0]->....)
Even though I have created this mapper
#Provider
#Component
public class JacksonExceptionMapper implements ExceptionMapper<JsonMappingException> {
#Override
public Response toResponse(JsonMappingException e) {
....
}
}
The code never reach this mapper.
Is there anything we need to do in order to catch these exceptions?
EDIT
Note: I have jus tried being less general and instead of JsonMappingException I use InvalidFormatException in this case the mapper is called. But I still don't understand because InvalidFormatException extends JsonMappingException and should be called as well
Had the same problem.
The problem is that JsonMappingExceptionMapper kicks in before your mapper. The actual exception is of class com.fasterxml.jackson.databind.exc.InvalidFormatException and the mapper defines com.fasterxml.jackson.jaxrs.base.JsonMappingException, so it's more specific to the exception.
You see, Jersey's exception handler looks to find the most accurate handler (see org.glassfish.jersey.internal.ExceptionMapperFactory#find(java.lang.Class, T)).
To override this behavior, simply disable the mapper from being used:
Using XML:
<init-param>
<param-name>jersey.config.server.disableAutoDiscovery</param-name>
<param-value>true</param-value>
</init-param>
Using code: resourceConfig.property(CommonProperties.FEATURE_AUTO_DISCOVERY_DISABLE, true); where resourceConfig is of type org.glassfish.jersey.server.ServerConfig.
You can also write your own specific mapper:
public class MyJsonMappingExceptionMapper implements ExceptionMapper<JsonMappingException>
But I think it's an over kill.
Hi it seems to exits an alternative answer now that does not require to disable Jersey AUTO_DISCOVERY feature.
Just annotate your own exception mapper with a #Priority(1) annotation. The lower the number, the higher the priority. Since Jackson's own mappers do not have any priority annotation, yours will be executed:
#Priority(1)
public class MyJsonMappingExceptionMapper implements ExceptionMapper<JsonMappingException>
Starting in version 2.29.1 [1], if you're registering the JacksonFeature, you can now do so without registering the exception mappers [2]:
register(JacksonFeature.withoutExceptionMappers());
[1] https://github.com/eclipse-ee4j/jersey/pull/4225
[2] https://eclipse-ee4j.github.io/jersey.github.io/apidocs/2.34/jersey/org/glassfish/jersey/jackson/JacksonFeature.html#withoutExceptionMappers--
I'm new to both Jackson and Spring, so please excuse me if this is a dumb question. I've been working on a simple spring project which handles JSON requests. I have GET and DELETE working, but I'm getting an error when I try to POST:
SEVERE: Servlet.service() for servlet [mvc-dispatcher] in context with path [/CynergyRestStarterKit] threw exception [Handler processing failed; ...with root cause
java.lang.NoSuchMethodError: org.codehaus.jackson.map.type.TypeFactory.type(Ljava/lang/reflect/Type;Lorg/codehaus/jackson/type/JavaType;)Lorg/codehaus/jackson/type/JavaType;
at org.springframework.http.converter.json.MappingJacksonHttpMessageConverter.getJavaType(MappingJacksonHttpMessageConverter.java:229)
Here is my Java service:
#RequestMapping(value = "/todos", method = RequestMethod.GET)
public #ResponseBody
List<TodoItem> getTodos() {
return tasks;
}
#RequestMapping(value = "/todo/create", method = RequestMethod.POST)
public #ResponseBody
TodoItem createTodo(#RequestBody TodoItem item) {
return null;
}
What am I doing wrong?
What version of Spring and Jackson are you using?
This seems to indicate a version issue.
I see that you are using 1.x of Jackson (codehaus vs fasterxml). I would upgrade both Spring and Jackson to the latest version.
I had the same problem using spring-webmvc 3.2.9, after several retires i found that my project needed the following libraries:
jackson-annotations-2.3.3
jackson-core-2.3.3
jackson-mapper-asl-1.9.13
jackson-core-asl-19.3
So adding these solved the problem
When we configure Spring AOP the JSON Results disappear for : AOPExression1
<aop:pointcut id="dmhMethodExecution"
expression="within(com.aditya.dmh..*)" />
So I added an exclusion for : AOPExpression1 as AOpExpression2
<aop:pointcut id="dmhMethodExecution"
expression="within(com.aditya.dmh..*)
and !within(com.aditya.dmh.controller..*)" />
in the ASPECTJ Expression
Still I donot see my JSON results from the controller which is a restful implementation.
package com.aditya.dmh.controller;
#Controller
public class EmployeeController {
private EmployeeServiceInterface employeeService;
#Autowired
public void setEmployeeService(EmployeeServiceInterface employeeService) {
this.employeeService = employeeService;
}
#RequestMapping("/employeeservices/1/allemployees.view")
public #ResponseBody Result<EmployeeModel> getEmployees(){
return employeeService.getEmployees(0, 10);
}
}
When I use log4j for the DEBUG messages I see the following:
15:37:04.214 [http-8090-1] DEBUG o.s.web.servlet.DispatcherServlet - Null ModelAndView returned to DispatcherServlet with name 'dmhServiceDispatcher': assuming HandlerAdapter completed request handling
15:37:04.214 [http-8090-1] DEBUG o.s.web.servlet.DispatcherServlet - Successfully completed request
When I remove the AOP the JSON results start to appear and I see that the additional Debug Message.
17:11:36.270 [http-8090-2] DEBUG o.s.w.s.m.m.a.RequestResponseBodyMethodProcessor - Written [com.aditya.Result#8a85268] as "application/json;charset=UTF-8" using [org.springframework.http.converter.json.MappingJackson2HttpMessageConverter#62ba2e48]
Looking at the Spring forums I understand that the Convertor is automatically configured when the
<mvc:annotation-driven/>
is used.
Is my problem of configuring AOP have anything to do with the RequestResponseBodymethodProcessor not being called.
Does this have anything to do with the proxies created around my controller when I use AOPExpression1. Why would an exclusion as in AOPExpression2 still have the problem.
Anyhelp would be appreciated
I belive that to intercept a request to a controller you should do it with MVC interceptors and not with aspects. What I did is to put into the applicationContext.xml this:
<mvc:interceptors>
<mvc:interceptor>
<mvc:mapping path="/employeeservices/1/allemployees.view"/>
<bean class="com.aditya.dmh.interceptor.ResultInterceptor" />
</mvc:interceptor>
</mvc:interceptors>
Now, the class ResultInterceptor is where you put the code you want to be done, for instance:
#Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
log.info("--- preHandle --- ");
return true;
}
At least this is the way I did it.
Hope it helps.
This is a bit of a speculation:
I think what is happening is a CGLIB based dynamic proxy is getting created for your controller (although you have excluded it explicitly in your new pointcut expression), if this happens then #RequestMapping annotations are not correctly detected(by `) and so the controller is not there to handle your REST request.
Can you try a few things:
Have an interface for the controller with the exact same methods that the controller handles, and put the #RequestMapping annotations there, this will handle cases where the dynamic proxy is created and should work as expected even if the dynamic proxy gets created..
Play around a little more with your pointcut expression to see why a proxy for you controller may be getting created.
THE SOLUTION FOR OUR PROBLEM IN THIS CONTEXT
We found out that the whole thing was with the Around Advice in AOP Configuration that we have had.
Before Fix
public void logAround(ProceedingJoinPoint joinPoint) throws Throwable {
long startTime = System.currentTimeMillis();
joinPoint.proceed();
long totalTime = System.currentTimeMillis() - startTime;
log.debug(buildLogMessage(new StringBuilder().append(METHOD_AROUND_ID)
.append("[").append(totalTime).append("] ").toString(),
joinPoint));
return returnValue;
}
After Fix
public Object logAround(ProceedingJoinPoint joinPoint) throws Throwable {
long startTime = System.currentTimeMillis();
Object returnValue = joinPoint.proceed();
long totalTime = System.currentTimeMillis() - startTime;
log.debug(buildLogMessage(new StringBuilder().append(METHOD_AROUND_ID)
.append("[").append(totalTime).append("] ").toString(),
joinPoint));
return returnValue;
}
the void effectively made sure that the Response Object sent by the logAround was not passed on back to the RequestResponseBodyMethodProcessor
Once we had it captured & returned the cglib proxies sent the response back to the processor & had the response sent back to the client.
I'm not sure whether this is a misconfiguration on my part, a misunderstanding of what can be accomplished via #ModelAttribute and automatic JSON content conversion, or a bug in either Spring or Jackson. If it turns out to be the latter, of course, I'll file an issue with the appropriate folks.
I've encountered a problem with adding a #ModelAttribute to a controller's handler method. The intent of the method is to expose a bean that's been populated from a form or previous submission, but I can reproduce the issue without actually submitting data into the bean.
I'm using the Spring mvc-showcase sample. It's currently using Spring 3.1, but I first encountered, and am able to reproduce, this issue on my 3.0.5 setup. The mvc-showcase sample uses a pretty standard servlet-context.xml:
servlet-context.xml
<?xml version="1.0" encoding="UTF-8"?>
<beans:beans xmlns="http://www.springframework.org/schema/mvc"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:beans="http://www.springframework.org/schema/beans"
xsi:schemaLocation="
http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc-3.1.xsd
http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-3.1.xsd">
<!-- DispatcherServlet Context: defines this servlet's request-processing infrastructure -->
<!-- Enables the Spring MVC #Controller programming model -->
<annotation-driven conversion-service="conversionService">
<argument-resolvers>
<beans:bean class="org.springframework.samples.mvc.data.custom.CustomArgumentResolver"/>
</argument-resolvers>
</annotation-driven>
<!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources in the ${webappRoot}/resources/ directory -->
<resources mapping="/resources/**" location="/resources/" />
<!-- Resolves views selected for rendering by #Controllers to .jsp resources in the /WEB-INF/views directory -->
<beans:bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
<beans:property name="prefix" value="/WEB-INF/views/" />
<beans:property name="suffix" value=".jsp" />
</beans:bean>
<!-- Imports user-defined #Controller beans that process client requests -->
<beans:import resource="controllers.xml" />
<!-- Only needed because we install custom converters to support the examples in the org.springframewok.samples.mvc.convert package -->
<beans:bean id="conversionService" class="org.springframework.samples.mvc.convert.CustomConversionServiceFactoryBean" />
<!-- Only needed because we require fileupload in the org.springframework.samples.mvc.fileupload package -->
<beans:bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver" />
</beans:beans>
The controllers.xml referenced in the file simply sets up the relevant component-scan and view-controller for the root path. The relevant snippet is below.
controllers.xml
<!-- Maps '/' requests to the 'home' view -->
<mvc:view-controller path="/" view-name="home"/>
<context:component-scan base-package="org.springframework.samples.mvc" />
The test bean which I am attempting to deliver is a dead-simple POJO.
TestBean.java
package org.springframework.samples.mvc.test;
public class TestBean {
private String testField = "test#example.com";
public String getTestField() {
return testField;
}
public void setTestField(String testField) {
this.testField = testField;
}
}
And finally, the controller, which is also simple.
TestController.java
package org.springframework.samples.mvc.test;
import org.springframework.stereotype.Controller;
import org.springframework.ui.Model;
import org.springframework.web.bind.annotation.ModelAttribute;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
#Controller
#RequestMapping("test/*")
public class TestController {
#ModelAttribute("testBean")
public TestBean getTestBean() {
return new TestBean();
}
#RequestMapping(value = "beanOnly", method = RequestMethod.POST)
public #ResponseBody
TestBean testBean(#ModelAttribute("testBean") TestBean bean) {
return bean;
}
#RequestMapping(value = "withoutModel", method = RequestMethod.POST)
public #ResponseBody
Model testWithoutModel(Model model) {
model.addAttribute("result", "success");
return model;
}
#RequestMapping(value = "withModel", method = RequestMethod.POST)
public #ResponseBody
Model testWithModel(Model model, #ModelAttribute("testBean") TestBean bean) {
bean.setTestField("This is the new value of testField");
model.addAttribute("result", "success");
return model;
}
}
If I call the controller via the mapped path /mvc-showcase/test/beanOnly, I get a JSON representation of the bean, as expected. Calling the withoutModel handler delivers a JSON representation of the Spring Model object associated with the call. It includes the implicit #ModelAttribute from the initial declaration in the return value, but the bean is unavailable to the method. If I wish to process the results of a form submission, for example, and return a JSON response message, then I need that attribute.
The last method adds the #ModelAttribute, and this is where the trouble comes up. Calling /mvc-showcase/test/withModel causes an exception.
In my 3.0.5 installation, I get a JsonMappingException caused by a lack of serializer for FormattingConversionService. In the 3.1.0 sample, the exception is caused by lack of serializer for DefaultConversionService. I'll include the 3.1 exception here; it seems to have the same root cause, even if the path is a bit different.
3.1 org.codehaus.jackson.map.JsonMappingException
org.codehaus.jackson.map.JsonMappingException: No serializer found for class org.springframework.format.support.DefaultFormattingConversionService and no properties discovered to create BeanSerializer (to avoid exception, disable SerializationConfig.Feature.FAIL_ON_EMPTY_BEANS) ) (through reference chain: org.springframework.validation.support.BindingAwareModelMap["org.springframework.validation.BindingResult.testBean"]->org.springframework.validation.BeanPropertyBindingResult["propertyAccessor"]->org.springframework.beans.BeanWrapperImpl["conversionService"])
at org.codehaus.jackson.map.ser.StdSerializerProvider$1.failForEmpty(StdSerializerProvider.java:89)
at org.codehaus.jackson.map.ser.StdSerializerProvider$1.serialize(StdSerializerProvider.java:62)
at org.codehaus.jackson.map.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:272)
at org.codehaus.jackson.map.ser.BeanSerializer.serializeFields(BeanSerializer.java:175)
at org.codehaus.jackson.map.ser.BeanSerializer.serialize(BeanSerializer.java:147)
at org.codehaus.jackson.map.ser.BeanPropertyWriter.serializeAsField(BeanPropertyWriter.java:272)
at org.codehaus.jackson.map.ser.BeanSerializer.serializeFields(BeanSerializer.java:175)
at org.codehaus.jackson.map.ser.BeanSerializer.serialize(BeanSerializer.java:147)
at org.codehaus.jackson.map.ser.MapSerializer.serializeFields(MapSerializer.java:207)
at org.codehaus.jackson.map.ser.MapSerializer.serialize(MapSerializer.java:140)
at org.codehaus.jackson.map.ser.MapSerializer.serialize(MapSerializer.java:22)
at org.codehaus.jackson.map.ser.StdSerializerProvider._serializeValue(StdSerializerProvider.java:315)
at org.codehaus.jackson.map.ser.StdSerializerProvider.serializeValue(StdSerializerProvider.java:242)
at org.codehaus.jackson.map.ObjectMapper.writeValue(ObjectMapper.java:1030)
at org.springframework.http.converter.json.MappingJacksonHttpMessageConverter.writeInternal(MappingJacksonHttpMessageConverter.java:153)
at org.springframework.http.converter.AbstractHttpMessageConverter.write(AbstractHttpMessageConverter.java:181)
at org.springframework.web.servlet.mvc.method.annotation.support.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:121)
at org.springframework.web.servlet.mvc.method.annotation.support.AbstractMessageConverterMethodProcessor.writeWithMessageConverters(AbstractMessageConverterMethodProcessor.java:101)
at org.springframework.web.servlet.mvc.method.annotation.support.RequestResponseBodyMethodProcessor.handleReturnValue(RequestResponseBodyMethodProcessor.java:81)
at org.springframework.web.method.support.HandlerMethodReturnValueHandlerComposite.handleReturnValue(HandlerMethodReturnValueHandlerComposite.java:64)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMethodAdapter.invokeHandlerMethod(RequestMappingHandlerMethodAdapter.java:505)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMethodAdapter.handleInternal(RequestMappingHandlerMethodAdapter.java:468)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:80)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:790)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:719)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:644)
at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:560)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:710)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:803)
at
...
So, is there some configuration I am missing that should allow the Jackson converter to properly handle a response derived from a handler with #ModelAttribute in the method signature? If not, any thoughts as to whether this is more likely a Spring bug or a Jackson bug? I'm leaning toward Spring, at this point.
It looks like a Spring config problem, when serializing to JSON the DefaultFormattingConversionService is empty and Jackson (by default) will throw an exception if a bean is empty see FAIL_ON_EMPTY_BEANS in the features documentation. But I am not clear why the bean is empty.
It should work if you set FAIL_ON_EMPTY_BEANS to false, but still doesn't really explain why it is happening in the first place.
DefaultFormattingConversionService is new to 3.1 - it extends the FormattingConversionService which explains the different exceptions between 3.0.5 and 3.1.
I do not think it is a Jackson problem, although a new version of Jackson (1.8.0) was released only 3 days ago so you could try that also.
I will try to reproduce this locally.