415 Unsupported MediaType for POST request in spring application

Question

I have a very simple Spring Application (NOT spring boot). I have implemented a GET and POST controller methods. the GET method works fine. But the POST is throwing 415 Unsupported MediaType. Steps to reproduce are available below

ServiceController. java

package com.example.myApp.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;


    @Controller
    @RequestMapping("/service/example")
    public class ServiceController {

        @RequestMapping(value="sample", method = RequestMethod.GET)
        @ResponseBody
    public String getResp() {
        return "DONE";
    }

    @RequestMapping(value="sample2", method = RequestMethod.POST, consumes = "application/json")
    @ResponseBody
    public String getResponse2(@RequestBody Person person) {
        return "id is " + person.getId();
    }

}

class Person {

    private int id;
    private String name;

    public Person(){

    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }
}

AppConfig.java

package com.example.myApp.app.config;

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.config.annotation.ResourceHandlerRegistry;
import org.springframework.web.servlet.config.annotation.WebMvcConfigurerAdapter;

@Configuration
@EnableWebMvc
@ComponentScan("com.example.myApp")
public class AppConfig extends WebMvcConfigurerAdapter {

    @Override
    public void addResourceHandlers(ResourceHandlerRegistry registry) {
        registry.addResourceHandler("/test/**").addResourceLocations("/test/").setCachePeriod(0);
        registry.addResourceHandler("/css/**").addResourceLocations("/css/").setCachePeriod(0);
        registry.addResourceHandler("/img/**").addResourceLocations("/img/").setCachePeriod(0);
        registry.addResourceHandler("/js/**").addResourceLocations("/js/").setCachePeriod(0);
    }
}

AppInitializer.java

package com.example.myApp.app.config;

import org.springframework.web.WebApplicationInitializer;
import org.springframework.web.context.ContextLoaderListener;
import org.springframework.web.context.support.AnnotationConfigWebApplicationContext;
import org.springframework.web.servlet.DispatcherServlet;

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

public class AppInitializer implements WebApplicationInitializer {

    @Override
    public void onStartup(ServletContext servletContext) throws ServletException {


        // Create the 'root' Spring application context
        AnnotationConfigWebApplicationContext rootContext =
                new AnnotationConfigWebApplicationContext();

        rootContext.register(AppConfig.class);
        servletContext.addListener(new ContextLoaderListener(rootContext));

        // Register and map the dispatcher servlet
        ServletRegistration.Dynamic dispatcher =
                servletContext.addServlet("dispatcher", new DispatcherServlet(rootContext));

        dispatcher.setLoadOnStartup(1);
        dispatcher.addMapping("/");

    }


}

The code is available here:

git clone https://bitbucket.org/SpringDevSeattle/springrestcontroller.git
./gradlew clean build tomatrunwar

This spins up embedded tomcat.

Now you can curl the following

curl -X GET -H "Content-Type: application/json" "http://localhost:8095/myApp/service/example/sample"

works fine

But

curl -X POST -H "Content-Type: application/json" '{
    "id":1,
    "name":"sai"
}' "http://localhost:8095/myApp/service/example/sample2"

Throws 415 unsupported MediaType

<body>
        <h1>HTTP Status 415 - </h1>
        <HR size="1" noshade="noshade">
        <p>
            <b>type</b> Status report
        </p>
        <p>
            <b>message</b>
            <u></u>
        </p>
        <p>
            <b>description</b>
            <u>The server refused this request because the request entity is in a format not supported by the requested resource for the requested method.</u>
        </p>
        <HR size="1" noshade="noshade">
        <h3>Apache Tomcat/7.0.54</h3>
    </body>

Answer 1

Accept Header might be the issue. As far as i remember, when you send a request via curl it adds a default header accept : */*
But in case of JSON you have to mention the accept header
as accept : application/json
similarly you have mentioned the content-Type.

And little more, i dont know what is that, but don't you think you have to place "request mappings" like that

@RequestMapping(value="/sample" ...
@RequestMapping(value="/sample2" ...

This may not be the case, but accept header is the thing, i think is the main issue.
Solution 2
Since you have this code

public String getResponse2(@RequestBody Person person)

I have already faced this problem before and the solution two may help here

FormHttpMessageConverter which is used for @RequestBody-annotated parameters when content type is application/x-www-form-urlencoded cannot bind target classes as @ModelAttribute can). Therefore you need @ModelAttribute instead of @RequestBody

Either Use @ModelAttribute annotation instead of @RequestBody like this

public String getResponse2(@ModelAttribute Person person)

I provided the same answer to somebody and it helped. here is that answer of mine