spring mvc not returning json content - error 406

Question

I am using Spring MVC with JSON as specified in Ajax Simplification Spring 3.0 article.

After so many attempts and variations of my code depending on advice found on

Answer 1

I have used java configuration and i got this same error. I have missed to add the @EnableWebMvc to the configuration file. This error is resolved after i add the @EnableWebMvc in my webconfig file.

Also the Object that is returned from your Spring Controller, should have proper getter and setter methods.

package com.raghu.dashboard.config;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.servlet.config.annotation.EnableWebMvc;
import org.springframework.web.servlet.support.AbstractAnnotationConfigDispatcherServletInitializer;
import org.springframework.web.servlet.view.InternalResourceViewResolver;

import com.raghu.dashboard.dao.ITaskDAO;
import com.raghu.dashboard.dao.TaskDAOImpl;


    @Configuration
    @EnableWebMvc  //missed earlier...after adding this it works.no 406 error
    @ComponentScan(basePackages = { "com.raghu.dashboard.api", "com.raghu.dashboard.dao" })
    public class WebConfig extends AbstractAnnotationConfigDispatcherServletInitializer {

        protected Class[] getRootConfigClasses() { return null;}

        protected Class[] getServletConfigClasses() {
            return new Class[] { MongoConfiguration.class};
        }

        protected String[] getServletMappings() {
            return new String[]{"*.htm"}; 
        }

        @Bean(name = "taskDao")
        public ITaskDAO taskDao() {
            return new TaskDAOImpl();
        }

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

    }

AppInitializer.java

package com.raghu.dashboard.config;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.ServletRegistration;

import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.ContextLoaderListener;
import org.springframework.web.context.WebApplicationContext;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.DispatcherServlet;
    public class AppInitalizer 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.register(com.raghu.dashboard.config.WebConfig.class);
            context.scan("com.raghu.dashboard.api");
            return context;
        }

    }

Also make sure the Object that is returned, has the proper getter and setter.

Example:

@RequestMapping(value = "/list", method = RequestMethod.GET, produces = MediaType.APPLICATION_JSON_VALUE)
@ResponseBody
public ResponseEntity findAll() {
    logger.info("Calling the findAll1()");
    TaskInfo taskInfo = dashboardService.getTasks();
    HttpHeaders headers = new HttpHeaders();
    headers.add("Access-Control-Allow-Origin", "*");
    ResponseEntity entity = new ResponseEntity(taskInfo,
            headers, HttpStatus.OK);
    logger.info("entity is := " + entity);
    return entity;
}

TaskInfo object should have proper getter and setter. if not, 406 error will be thrown.

POM File for Reference:

    4.0.0
    com.raghu.DashBoardService
    DashBoardService
    war
    0.0.1-SNAPSHOT
    DashBoardService Maven Webapp
    http://maven.apache.org
    
        
        4.0.6.RELEASE
        2.4.0
        2.2.11
        1.2.17
    

    
        
            junit
            junit
            3.8.1
            test
        

        
            org.mongodb
            mongo-java-driver
            2.10.1
        
        
        
            org.springframework.data
            spring-data-mongodb
            1.4.1.RELEASE
        

        
            org.springframework
            spring-beans
            ${spring-framework.version}
        

        
            org.springframework
            spring-core
            ${spring-framework.version}
        

        
            org.springframework
            spring-context
            ${spring-framework.version}
        

        
            org.springframework
            spring-web
            ${spring-framework.version}
        

        
            org.springframework
            spring-webmvc
            ${spring-framework.version}
        
        
            cglib
            cglib
            3.1
        

        
            org.springframework
            spring-expression
            ${spring-framework.version}
        

        
            org.springframework
            spring-aop
            ${spring-framework.version}
        


    org.springframework
    spring-tx
    ${spring-framework.version}




    org.springframework
    spring-dao
    2.0.3




        
        
            com.fasterxml.jackson.core
            jackson-core
            2.2.3
        
        
            com.fasterxml.jackson.core
            jackson-databind
            2.2.3
        
        
            com.fasterxml.jackson.core
            jackson-annotations
            2.2.3
        

        
            javax.servlet
            javax.servlet-api
            3.0.1
        

        
            com.google.code.gson
            gson
            1.7.1
        

        
        
            log4j
            log4j
            ${log4j.version}
        

        
            org.springframework.data
            spring-data-commons
            1.5.0.RELEASE
        

    

    
        DashBoardService
        
            
                src/main/resources
                true
            
        
        
            
                org.apache.maven.plugins
                maven-compiler-plugin
                3.5.1
                
                    1.8
                    1.8
                
            
            
                org.apache.maven.plugins
                maven-war-plugin
                2.6
                
                    false