Spring RestController - jQuery PUT works only when changing certain values

Hello and thank you in advanced:

I'm using Spring 4 and jquery trying to PUT data to a RestController. I have three values that are passed to the controller: id, name, genre. For some reason, the PUT request works every time that I change the name field, but if I try to update just the genre field, the request never even hits the controller and fails with 400: Bad Request.

I'm totally stumped. My GET, POST, and DELETE methods are working just fine too. I'm going to include my config stuff since there's a good possibility that may be the issue...

manage-artist.js (knockout and jquery):

...

    //update artist
    self.updateArtist = function(artist){
        self.clearMessages();

        //put to database
        $.ajax({                 
            url: "../artist/" + artist.id(), 
            method: "PUT",
            data: "id="+artist.id()+"&name="+artist.name()+"&genre="+artist.genre(),
            datatype: "json",
            success: function (data) { 
                console.log("Artist succesfully updated.");

                //update message
                self.successMessage("Artist successfully updated.");
            }, 
            error: function (err) { 
                console.log("An error occured while trying to update artist.");

                //extract json response
                self.errorResponse(err.responseJSON);

                //...more error handling
            } 

        }); 
    };

...

ArtistController.java:

@RestController
@RequestMapping(value="/artist")
public class ArtistController {

    @Autowired
    private ArtistService artistService;

    @Autowired
    private ArtistValidator artistValidator;

    @InitBinder
    private void initBinder(WebDataBinder binder) {
        binder.setValidator(artistValidator);
    }

    @RequestMapping(value="/", method=RequestMethod.GET)
    public List<Artist> newArtistPage() {
        return artistService.findAll();
    }

    @RequestMapping(value="/{id}", method=RequestMethod.GET)
    public Artist artistListPage(@PathVariable Integer id) {
        return artistService.findById(id);
    }

    @RequestMapping(value="/", method=RequestMethod.POST)
    public Artist createArtist(@ModelAttribute @Valid Artist artist,
            BindingResult result) {

        //If there's validation errors
        if (result.hasErrors())
            throw new InvalidRequestException("Error creating artist", result);

        return artistService.create(artist);    
    }

    @RequestMapping(value="/{id}", method=RequestMethod.PUT)
    public Artist editArtist(@ModelAttribute @Valid Artist artist, @PathVariable Integer id,
            BindingResult result) {

        //If there's validation errors
        if (result.hasErrors())
            throw new InvalidRequestException("Error updating artist", result);

        //call update service
        Artist updatedArtist;
        try {
            updatedArtist = artistService.update(artist);
        } catch (ArtistNotFoundException e) {
            throw new ResourceNotFoundException("Unable to update artist with ID = "+ id
                    +". No such artist exists.");
        }

        return updatedArtist;
    }

    @RequestMapping(value="/{id}", method=RequestMethod.DELETE)
    public Artist deleteArtist(@PathVariable Integer id)
    {   
        //call delete service
        Artist deletedArtist;
        try {
            deletedArtist = artistService.delete(id);
        } catch (ArtistNotFoundException e) {
            throw new ResourceNotFoundException("Unable to delete artist with ID = "+ id
                    +". No such artist exists.");
        }

        return deletedArtist;
    }

}

Initializer.java:

public class Initializer implements WebApplicationInitializer {

    private static final String DISPATCHER_SERVLET_NAME = "dispatcher";

    public void onStartup(ServletContext servletContext)
            throws ServletException {
        AnnotationConfigWebApplicationContext ctx = new AnnotationConfigWebApplicationContext();
        ctx.register(WebAppConfig.class);
        servletContext.addListener(new ContextLoaderListener(ctx));

        ctx.setServletContext(servletContext);

        Dynamic servlet = servletContext.addServlet(DISPATCHER_SERVLET_NAME,
                new DispatcherServlet(ctx));
        servlet.addMapping("/");
        servlet.setLoadOnStartup(1);
    }

}

WebAppConfig.java:

@Configuration
@EnableWebMvc
@EnableTransactionManagement
@ComponentScan("com.project.jukebox")
@PropertySource("classpath:jdbc.properties")
@EnableJpaRepositories("com.project.jukebox.repositories")
public class WebAppConfig extends WebMvcConfigurerAdapter {

    private static final String PROPERTY_NAME_DATABASE_DRIVER = "jdbc.driver";
    private static final String PROPERTY_NAME_DATABASE_PASSWORD = "jdbc.password";
    private static final String PROPERTY_NAME_DATABASE_URL = "jdbc.url";
    private static final String PROPERTY_NAME_DATABASE_USERNAME = "jdbc.username";

    private static final String PROPERTY_NAME_HIBERNATE_DIALECT = "hibernate.dialect";
    private static final String PROPERTY_NAME_HIBERNATE_SHOW_SQL = "hibernate.show_sql";
    private static final String PROPERTY_NAME_ENTITYMANAGER_PACKAGES_TO_SCAN = "entitymanager.packages.to.scan";

    @Resource
    private Environment env;

    @Bean
    public DataSource dataSource() {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();

        dataSource.setDriverClassName(env.getRequiredProperty(PROPERTY_NAME_DATABASE_DRIVER));
        dataSource.setUrl(env.getRequiredProperty(PROPERTY_NAME_DATABASE_URL));
        dataSource.setUsername(env.getRequiredProperty(PROPERTY_NAME_DATABASE_USERNAME));
        dataSource.setPassword(env.getRequiredProperty(PROPERTY_NAME_DATABASE_PASSWORD));

        return dataSource;
    }

    @Bean
    public LocalContainerEntityManagerFactoryBean entityManagerFactory() {
        LocalContainerEntityManagerFactoryBean entityManagerFactoryBean = new LocalContainerEntityManagerFactoryBean();
        entityManagerFactoryBean.setDataSource(dataSource());
        entityManagerFactoryBean.setPersistenceProviderClass(HibernatePersistenceProvider.class);
        entityManagerFactoryBean.setPackagesToScan(env.getRequiredProperty(PROPERTY_NAME_ENTITYMANAGER_PACKAGES_TO_SCAN));

        entityManagerFactoryBean.setJpaProperties(hibProperties());

        return entityManagerFactoryBean;
    }

    private Properties hibProperties() {
        Properties properties = new Properties();
        properties.put(PROPERTY_NAME_HIBERNATE_DIALECT, env.getRequiredProperty(PROPERTY_NAME_HIBERNATE_DIALECT));
        properties.put(PROPERTY_NAME_HIBERNATE_SHOW_SQL, env.getRequiredProperty(PROPERTY_NAME_HIBERNATE_SHOW_SQL));
        properties.put("hibernate.hbm2ddl.auto", "create-drop");
        return properties;
    }

    @Bean
    public JpaTransactionManager transactionManager() {
        JpaTransactionManager transactionManager = new JpaTransactionManager();
        transactionManager.setEntityManagerFactory(entityManagerFactory().getObject());
        return transactionManager;
    }

    @Bean
    public ResourceBundleMessageSource messageSource() {
        ResourceBundleMessageSource source = new ResourceBundleMessageSource();
        source.setBasename(env.getRequiredProperty("message.source.basename"));
        source.setUseCodeAsDefaultMessage(true);
        return source;
    }

    @Bean
      public InternalResourceViewResolver getInternalResourceViewResolver() {
        InternalResourceViewResolver resolver = new InternalResourceViewResolver();
        resolver.setPrefix("/WEB-INF/views/");
        resolver.setSuffix(".jsp");
        return resolver;
      }

      @Override
      public void configureDefaultServletHandling(DefaultServletHandlerConfigurer configurer) {
        configurer.enable();
      }

      @Bean
      public WebContentInterceptor webContentInterceptor() {
        WebContentInterceptor interceptor = new WebContentInterceptor();
        interceptor.setCacheSeconds(0);
        interceptor.setUseExpiresHeader(true);
        interceptor.setUseCacheControlHeader(true);
        interceptor.setUseCacheControlNoStore(true);

        return interceptor;
      }

      @Override
      public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/resources/**").addResourceLocations("/resources/");
        registry.addResourceHandler("/lib/**").addResourceLocations("/WEB-INF/lib/");
        registry.addResourceHandler("/scripts/**").addResourceLocations("/WEB-INF/scripts/");
        registry.addResourceHandler("/styles/**").addResourceLocations("/WEB-INF/styles/");
        registry.addResourceHandler("/fonts/**").addResourceLocations("/WEB-INF/fonts/");
      }

      @Override
      public void addInterceptors(InterceptorRegistry registry) {
        registry.addInterceptor(webContentInterceptor());
      }

}

Web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://ift.tt/ra1lAU"
    xmlns="http://ift.tt/nSRXKP" xmlns:web="http://ift.tt/LU8AHS"
    xsi:schemaLocation="http://ift.tt/nSRXKP http://ift.tt/1eWqHMP"
    version="3.0">

    <display-name>jukebox</display-name>

    <!-- filters needed for put requests, known bug with spring rest -->
    <filter>
        <filter-name>HttpPutFormContentFilter</filter-name>
        <filter-class>org.springframework.web.filter.HttpPutFormContentFilter</filter-class>
    </filter>

    <filter-mapping>
        <filter-name>HttpPutFormContentFilter</filter-name>
        <url-pattern>/*</url-pattern>
        <servlet-name>dispatcher</servlet-name>
    </filter-mapping>

</web-app>