Spring web app returns HTTP Status 406 - spring

Question

I'm creating a basic spring based web app:
pom dependencies:
<properties>
<java-version>1.8</java-version>
<springframework-version>4.3.3.RELEASE</springframework-version>
<jackson-version>2.8.3</jackson-version>
<org.slf4j-version>1.7.6</org.slf4j-version>
<logback.version>1.1.7</logback.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-webmvc</artifactId>
<version>${springframework-version}</version>
</dependency>
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-web</artifactId>
<version>${springframework-version}</version>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>javax.servlet-api</artifactId>
<version>3.0.1</version>
<scope>provided</scope>
</dependency>
<!-- Jackson JSON Mapper -->
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>${jackson-version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>${jackson-version}</version>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-annotations</artifactId>
<version>${jackson-version}</version>
</dependency>
<!-- Logging -->
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>${org.slf4j-version}</version>
</dependency>
<dependency>
<groupId>ch.qos.logback</groupId>
<artifactId>logback-classic</artifactId>
<version>${logback.version}</version>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
<version>1.2</version>
</dependency>
<!-- #Inject -->
<dependency>
<groupId>javax.inject</groupId>
<artifactId>javax.inject</artifactId>
<version>1</version>
</dependency>
</dependencies>
In order to skip the usage of web.xml I'm using WebApplicationInitializer:
public class AppInitializer implements WebApplicationInitializer {
#Override
public void onStartup(ServletContext servletContext) throws ServletException {
WebApplicationContext context = getContext();
servletContext.addListener(new ContextLoaderListener(context));
ServletRegistration.Dynamic dispatcher = servletContext.addServlet("DispatcherServlet", new DispatcherServlet(context));
dispatcher.setLoadOnStartup(1);
dispatcher.addMapping("/*");
}
private AnnotationConfigWebApplicationContext getContext() {
AnnotationConfigWebApplicationContext context = new AnnotationConfigWebApplicationContext();
context.setConfigLocation(SpringModule.class.getPackage().getName());
return context;
}
Here is my spring config class:
#Configuration
#ComponentScan(basePackages = "com.company.app")
public class SpringModule extends WebMvcConfigurerAdapter {
public SpringModule() {
super();
}
private MappingJackson2HttpMessageConverter customJackson2HttpMessageConverter() {
MappingJackson2HttpMessageConverter jsonConverter = new MappingJackson2HttpMessageConverter();
ObjectMapper objectMapper = new ObjectMapper();
objectMapper.configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
jsonConverter.setObjectMapper(objectMapper);
return jsonConverter;
}
#Override
public void configureMessageConverters(List<HttpMessageConverter<?>> messageConverters) {
messageConverters.add(customJackson2HttpMessageConverter());
messageConverters.add(new Jaxb2RootElementHttpMessageConverter());
messageConverters.add(new StringHttpMessageConverter());
messageConverters.add(new ByteArrayHttpMessageConverter());
messageConverters.add(new ResourceHttpMessageConverter());
messageConverters.add(new SourceHttpMessageConverter());
messageConverters.add(new FormHttpMessageConverter());
super.configureMessageConverters(messageConverters);
}
/*
* Configure ContentNegotiationManager
*/
#Override
public void configureContentNegotiation(ContentNegotiationConfigurer configurer) {
configurer.ignoreAcceptHeader(true).defaultContentType(
MediaType.APPLICATION_JSON);
}
Here is my test controller:
#Controller
#RequestMapping(value = "/user")
public class SomeController {
#RequestMapping(value = "/", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
#ResponseBody
public Person helloElad() {
return new Person("some name");
}
}
When testing the controller (using browser) I'm getting:
If I'm returning a plain String it works fine.
I tries to debug method configureMessageConverters and configureContentNegotiation but for some reason it never gets there (on bootstrapping), I'm not sure it is related to the problem though.
Any ideas?

Answer 1

HTTP 406 is an indication that your request content is not negotiated, it is probably that necessary http message converters are not found in configuration. Simple way to add basic set of message converter would be annotating your controller #EnableMvc

Answer 2

I had the same problem and couldn't find a solution here or elsewhere.
I also tried the advice of applying #EnableMvc on my AppConfig but that caused a different problem in which Tomcat wouldn't even successfully start up.
Eventually, I had to rewrite my AppInit class as follows:
https://github.com/viralpatel/spring4-restful-example/tree/master/src/main/java/net/viralpatel/spring/config
Now, I'm getting JSON back when I return a POJO. I don't like this fix. The code seems incomplete compared to the AppInit shown in the problem here, but I'm unstuck.