Content type 'text/plain;charset=UTF-8' not supported

Q: Send the correct Content-Type header

When to use: Use this when your Spring Boot code is correct, but the client is sending the wrong header.. If your method expects @RequestBody mapped to an object, Spring needs the client to tell it the data is JSON via the Content-Type: application/json header.

Q: Add 'consumes' to your mapping annotation

When to use: Use this if you want to strictly restrict an endpoint to only accept JSON.. Explicitly declaring consumes = MediaType.APPLICATION_JSON_VALUE ensures Spring only routes JSON requests to this method.

Q: Ensure Jackson is on the classpath

When to use: Use this if you are sending the correct header but still getting 415.. Spring Boot auto-configures JSON converters using Jackson. If the jackson-databind dependency is missing, Spring doesn't know how to parse JSON.

🔴 The Error You're Seeing

Confirm this matches your console output. If it does, you're in the right place.

ERROR LOG

2026-02-14 10:05:22.120  WARN 8842 --- [nio-8080-exec-2] .w.s.m.s.DefaultHandlerExceptionResolver : Resolved [org.springframework.web.HttpMediaTypeNotSupportedException: Content type 'text/plain;charset=UTF-8' not supported]

⚡ Quick Fix Works 80% of the time

Set the Content-Type header to application/json in your API client (Postman/curl).

curl -X POST http://localhost:8080/api/users -H "Content-Type: application/json" -d '{"name":"Deva"}'

🧠 Why this Happens

Tap to expand the deep technical explanation

The client sent an HTTP request with a Content-Type header (like text/plain or application/xml) that your Spring Boot controller method does not understand. By default, Spring Boot's @RestController expects and parses application/json.

The HITEC City Parking Spot Analogy:

It is like sending a document written in French to a translator who only speaks English. The translator (Spring) rejects the document because they don't support that language (Media Type).

🔁 How to Reproduce Confirm this is your error

Send a request with Content-Type: text/plain to a @PostMapping that consumes application/json. The API returns 415 Unsupported Media Type.

🛠️ Solutions (3 Ways to Fix)

Solution 1✓ Most common cause

Send the correct Content-Type header

👉 Use this when your Spring Boot code is correct, but the client is sending the wrong header.

If your method expects @RequestBody mapped to an object, Spring needs the client to tell it the data is JSON via the Content-Type: application/json header.

// In Postman: Go to Headers tab -> Add Key: Content-Type, Value: application/json
// In curl: add -H "Content-Type: application/json"

Solution 2

Add 'consumes' to your mapping annotation

👉 Use this if you want to strictly restrict an endpoint to only accept JSON.

Explicitly declaring consumes = MediaType.APPLICATION_JSON_VALUE ensures Spring only routes JSON requests to this method.

@PostMapping(value = "/users", consumes = MediaType.APPLICATION_JSON_VALUE)
public ResponseEntity<?> createUser(@RequestBody UserRequest request) { ... }

Solution 3

Ensure Jackson is on the classpath

👉 Use this if you are sending the correct header but still getting 415.

Spring Boot auto-configures JSON converters using Jackson. If the jackson-databind dependency is missing, Spring doesn't know how to parse JSON.

<!-- pom.xml -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency> <!-- This includes Jackson automatically -->

📋 Version Notes

Spring Boot 2.x

Standard HttpMessageConverter behavior.

Spring Boot 3.x

Identical behavior, but uses Jakarta Servlet APIs under the hood.

🛡️ How to Prevent This Next Time

Always standardize your API clients to send Content-Type: application/json for POST/PUT requests.