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
Related
I have a Spring controller annotated class which implements this method:
#RequestMapping(value = "/event/eventList", method = RequestMethod.GET)
public #ResponseBody List<Event> listEvents() {
System.out.println("############ LIST EVENTS ############");
List<Event> events = eventService.listAllEvents();
for(Event event : events) {
Hibernate.getClass(event);
System.out.println(event);
}
return events;
}
when I call the page (localhost:8080/myapp/event/eventList) from browser, the method will be called correctly i see all the logs and the events are printed correctly meaning the event list is not empty and valid, but I get the error:
GRAVE: Servlet.service() for servlet [dispatcher] in context with path [/myapp] threw exception [Request processing failed; nested exception is java.lang.UnsupportedOperationException: Attempted to serialize java.lang.Class: org.hibernate.proxy.HibernateProxy. Forgot to register a type adapter?] with root cause
java.lang.UnsupportedOperationException: Attempted to serialize java.lang.Class: org.hibernate.proxy.HibernateProxy. Forgot to register a type adapter?
It does not return any Json representation.
I changed the method to return a string like:
#RequestMapping(value = "/event/eventList", method = RequestMethod.GET)
public #ResponseBody String listEvents() {
return "{'pippo':1}";
}
In this case the browser show the string correctly.
did I miss something?
The exception is thrown by com.google.gson.internal.bind.TypeAdapters when GSON is trying to serialize variable 'events' to Json.
This happens, cause
eventService.listAllEvents()
returns not a list already containing all events, but hibernate proxy that will do that lazy, when the list is actually used.
GSON does not know how to serialize that proxy.
Hibernate.getClass should initialize the underlying object as a side effect.
You need to call it also for the List 'events' itself, not only for every single event. The List can be a hibernate proxy also.
You may find more info on that topic at
Could not serialize object cause of HibernateProxy
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)
I have a spring boot application and am testing integration test. My REST service produces JSON and I can confirm it when testing it in postman.
But when I make a getForObject call by restTemplate:
#Test
public void testGetObject() {
Pet pet = restTemplate.getForObject("http://localhost:9000/pets/10000", User.class, Collections.emptyMap());
assertThat(pet.getName(), is("Bobby"));
}
It fails with following error:
Could not extract response: no suitable HttpMessageConverter found for response type [class petstore.entity.User] and content type [text/html;charset=utf-8]
I read lots of posts in stackoverflow, and having that restTempalte itself has MappingJackson2HttpMessageConverter as one of default converters which has JSON as default media type then I should not get this error.
Is there anything I am missing here?
Well, the message is pretty indicative - you're getting text/html as a response type, make your endpoint return application/json. If you're using Spring MVC then you can do it by adding the produces parameter to the annotation:
#RequestMapping(value = "/pets/{id}", method = RequestMethod.GET, produces = "application/json")
Or, if you're using Jersey, add this annotation to your method:
#Produces("application/json")
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.
Hi I am trying to write small app with REST Json. I have some method that returns ArrayList of entity objects. And I am doing that:
#RequestMapping(value="/workers/", method = RequestMethod.GET)
public #ResponseBody ArrayList<Workers> showAllEmployes() throws Exception
{
ArrayList<Workers> workers = new ArrayList<Workers>();
workers = (ArrayList<Workers>) spiroService.getAllWorkers();
return workers;
}
And after this I got:
HTTP Status 500. The server encountered an internal error that prevented it from fulfilling this request.
When I try to return primitive data type then all is ok. I have nothing in server logs. And I have necessary imports. Please some tip.
Seems you have issue in produce json format, try this.
#RequestMapping(value = "/workers/", method = RequestMethod.GET,
produces={MediaType.APPLICATION_JSON_VALUE})