Getting 415 errors in Spring Boot app claiming application/json is not a supported media type

[Robert Dennett]

I am developing a sample app and getting a 415 error stating that application/json is not supported.  I've been tearing my hair out, but am not finding any issue.
I am cribbing the idea from this tutorial:

Spring Boot tutorial (chapter on implementing a POST method)

I am sending the request and confirmed that the request body is valid JSON.  Here is what I believe to be the relevant code:

package com.robertdennett.orderTracker.controller;

import com.robertdennett.orderTracker.model.Customer;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;
import java.util.Optional;

@RestController
@RequestMapping(path = "api/v1/customer")
public class CustomerController {

    @Autowired
    private CustomerService customerService;

    @PostMapping
    public void addNewCustomer(@RequestBody Customer cust) {
        System.out.println(cust);
    }
}

Error from Postman:

{
    "timestamp": "2023-05-05T14:03:19.770+00:00",
    "status": 415,
    "error": "Unsupported Media Type",
    "trace": "org.springframework.web.HttpMediaTypeNotSupportedException: Content-Type 'application/json;charset=UTF-8' is not supported\n\tat org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodArgumentResolver.readWithMessageConverters(AbstractMessageConverterMethodArgumentResolver.java:209)\n\tat org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.readWithMessageConverters(RequestResponseBodyMethodProcessor.java:163)\n\tat org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor.resolveArgument(RequestResponseBodyMethodProcessor.java:136)\n\tat org.springframework.web.method.support.HandlerMethodArgumentResolverComposite.resolveArgument(HandlerMethodArgumentResolverComposite.java:122)\n\tat org.springframework.web.method.support.InvocableHandlerMethod.getMethodArgumentValues(InvocableHandlerMethod.java:181)\n\tat org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:148)\n\tat org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:118)\n\tat org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:884)\n\tat org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:797)\n\tat org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)\n\tat org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1081)\n\tat org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:974)\n\tat org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1011)\n\tat org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:914)\n\tat jakarta.servlet.http.HttpServlet.service(HttpServlet.java:590)\n\tat org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:885)\n\tat jakarta.servlet.http.HttpServlet.service(HttpServlet.java:658)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:205)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)\n\tat org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)\n\tat org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)\n\tat org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)\n\tat org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)\n\tat org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116)\n\tat org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)\n\tat org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)\n\tat org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:166)\n\tat org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90)\n\tat org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:482)\n\tat org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:115)\n\tat org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93)\n\tat org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)\n\tat org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:341)\n\tat org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:390)\n\tat org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63)\n\tat org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:894)\n\tat org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1741)\n\tat org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52)\n\tat org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)\n\tat org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)\n\tat org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)\n\tat java.base/java.lang.Thread.run(Thread.java:833)\n",
    "message": "Content-Type 'application/json;charset=UTF-8' is not supported.",
    "path": "/api/v1/customer"
}

Screenshot of the Postman settings attached.

[Ron McLeod]

Robert Dennett wrote:I am developing a sample app and getting a 415 error stating that application/json is not supported.

I'm not a Spring developer, but in other frameworks you typically need to specify the type of content that the handler consumes.

For example: @PostMapping(consumes = MediaType.APPLICATION_JSON_VALUE)

[Robert Dennett]

Ron McLeod wrote:

Robert Dennett wrote:I am developing a sample app and getting a 415 error stating that application/json is not supported.

I'm not a Spring developer, but in other frameworks you typically need to specify the type of content that the handler consumes.

For example: @PostMapping(consumes = MediaType.APPLICATION_JSON_VALUE)

Everything I can find says that that's the default media type for Spring Boot apps.  In any case, I tried adding the "consumes" attribute and it made no difference.

Thanks,
Rob

[Ron McLeod]

I assume that the object mapper requires that the class specified in the @RequestBody has a non-private no args constructor (either explicit or a default constructor)?  Does your Customer class have one?

[Robert Dennett]

Ron McLeod wrote:I assume that the object mapper requires that the class specified in the @RequestBody has a non-private no args constructor (either explicit or a default constructor)?  Does your Customer class have one?

It should since I added the Lombok annotations @NoArgsConstructor and @AllArgsConstructor:

package com.robertdennett.orderTracker.model;

import com.fasterxml.jackson.annotation.JsonManagedReference;
import jakarta.persistence.*;
import lombok.*;

import java.util.List;

import static jakarta.persistence.GenerationType.SEQUENCE;

@Entity
@Getter
@Setter
@AllArgsConstructor
@NoArgsConstructor
@Builder
public class Customer {

    @Id
    @SequenceGenerator(
            name = "customer_sequence",
            sequenceName = "customer_sequence",
            allocationSize = 1
    )
    @GeneratedValue(
            strategy = SEQUENCE,
            generator = "customer_sequence"
    )
    private Long id;

    private String name;

    @OneToMany(mappedBy = "customer", cascade = CascadeType.ALL)
    @JsonManagedReference
    private List<Order> orders;
}

[Robert Dennett]

I also tried commenting out the Lombok annotations except for Builder and manually adding an all args constructor, a no args constructor and getters and setters for all fields, all generated using Intellij's generators.

[Ron McLeod]

For troubleshooting, try simplifying your Customer class to something bare bones like:

public class Customer {
    String name;
	
	@Override
	public String toString() {
		return "name: " + name;
	}
}

[Robert Dennett]

Ron McLeod wrote:For troubleshooting, try simplifying your Customer class to something bare bones like:

public class Customer {
    String name;
	
	@Override
	public String toString() {
		return "name: " + name;
	}
}

Well, stripping out the other fields was proving to be too complicated in my app, so I created a new one with only one field called name and it worked just fine.

I then tried modifying the JSON sent to the request like this:

{
    "id": 2,
    "name": "bar",
    "orders": []
}

but got the same error.

I also created this in the controller

class Foo {
    private String name;

    @Override
    public String toString() {
        return "Foo{" +
                "name='" + name + '\'' +
                '}';
    }
}

and added this method to the controller

    @PostMapping("test")
    public void test(@RequestBody Foo f) {
        System.out.println(f);
    }

I also get the 415 error when I try to call it.

[Robert Dennett]

Strike that, the api/v1/customer/test method worked just fine.  I had forgotten to set the content type to application/json.

So it appears that the Customer class can't be hydrated properly.  If that's the case, what needs to change?

[Ron McLeod]

You may need to tweak the configuration for the object mapper to define how it should deal with extra or missing attributes in the JSON payload.

According to this Baeldung post, the default configuration includes: DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES.

Edit: I'm not sure if this is relevant anymore; I was responding to your earlier post

[Robert Dennett]

OK, so this field in the Customer class is what's doing it:

    @OneToMany(mappedBy = "customer", cascade = CascadeType.ALL)
    @JsonManagedReference
    private List<Order> orders;

Since a customer may have no orders, I want to be able to create a customer without passing anything into orders, but I don't think that it's the deserializer that's the problem.  I commented out the above and added another field called "test".

Passing both

{
  "name": "bar"
}

and

{
  "name": "bar",
  "test": ";lskdfj"
}

worked just fine.  I would also expect to get a different error than a 415.

[Paul Clapham]

The post title wrote:Getting 415 errors in Spring Boot app

I read this and thought "Wow, that's a lot of errors." However I see you're making good progress on your one error.  

[Ron McLeod]

Does the stack trace in the error message provide any clues?  The original one you shared pointed back to the AbstractMessageConverterMethodArgumentResolver#readWithMessageConverters method.  Is it still the same now?

org.springframework.web.HttpMediaTypeNotSupportedException:  Content-Type 'application/json;charset=UTF-8' is not supported org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodArgumentResolver  .readWithMessageConverters(AbstractMessageConverterMethodArgumentResolver.java:209) org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor  .readWithMessageConverters(RequestResponseBodyMethodProcessor.java:163)

[Robert Dennett]

I should have specified HTTP 415 Unsupported Media Type errors.  That said, I am still stuck.

[Robert Dennett]

Ron McLeod wrote:Does the stack trace in the error message provide any clues?  The original one you shared pointed back to the AbstractMessageConverterMethodArgumentResolver#readWithMessageConverters method.  Is it still the same now?

org.springframework.web.HttpMediaTypeNotSupportedException:  Content-Type 'application/json;charset=UTF-8' is not supported org.springframework.web.servlet.mvc.method.annotation.AbstractMessageConverterMethodArgumentResolver  .readWithMessageConverters(AbstractMessageConverterMethodArgumentResolver.java:209) org.springframework.web.servlet.mvc.method.annotation.RequestResponseBodyMethodProcessor  .readWithMessageConverters(RequestResponseBodyMethodProcessor.java:163)

Yeah, it's the same.

[Ron McLeod]

Could this be a persistence-related issue which is being reported as an unsupported media problem?

Maybe try a request which has a non-empty array for the orders property.

[Robert Dennett]

I found this on SO

https://stackoverflow.com/questions/55190548/status-415-error-unsupported-media-type-for-post-request-onetomany-many

Which makes me think that I shouldn't use my Customer class (which is an @Entity) in the controller.  The quote in question:

Never use entity classes for data exchange on a rest service. Learn about 3 tier architecture –
Jens
Mar 15, 2019 at 20:57

is that what's going on here?

[Robert Dennett]

I think I finally licked this.

Rather than trying to deserialize to my entity, I am using a record as a DTO and then building the entity from that and passing it to the service layer.  It works insofar as it returns a 200 and stores my data in the DB, but I can't say that it's THE solution.  Here's the code snippet from the controller class:

    record NewCustomerRequest(String name) {}

    @PostMapping
    public void addNewCustomer(@RequestBody NewCustomerRequest request) {
        Customer cust = Customer.builder()
                .name(request.name())
                .build();
        customerService.createCustomer(cust);
    }

[Ron McLeod]

Seems like a good idea - it decouples the API from the entity definition, allowing them to evolve independently.

[Liutauras Vilda]

Couple of other things.

This:
api/v1/customer

You'd be better to name as (plural):
api/v1/customers

That's the convention. So you'd end up with:

POST api/v1/customers
GET  api/v1/customers/{id}

If your API has a tendency to grow, consider creating OpenAPI spec i.e. defined in Swagger for your API which would allow you to design and document API upfront and so later you could generate server stubs and add them to your project (Spring) and implement. Also you'd get the required DTOs generated. And you wouldn't need to type those API mappings by hand.