Spring @RequestBody Annotation

In the Spring framework, the @RequestBody annotation maps the web request’s body to the method’s parameter, usually a domain object or a Map.

Table of contents

• 1. Spring @RequestBody example
• 2. Spring @RequestBody example – Map version
• 3. Download Source Code
• 4. References

1. Spring @RequestBody example

Below is a @RequestBody example to map the request body (usually JSON data) to the method parameter LoginObject.

package com.mkyong;

public class LoginObject {
  private String username;
  private String password;

  public LoginObject(String username, String password) {
      this.username = username;
      this.password = password;
  }

  //getters setters...
}

package com.mkyong;

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.RestController;

@RestController
public class HelloController {

  // @RequestBody maps web request's body to method parameter LoginObject
  @RequestMapping(path = "/login", method = RequestMethod.POST)
  public boolean validateLogin(@RequestBody LoginObject login) {

      if (login == null) return false;
      String username = login.getUsername();
      String password = login.getPassword();

      // simple check
      if ("mkyong".equalsIgnoreCase(username) && "123456".equals(password)) {
          return true;
      } else {
          return false;
      }
  }

}

Try to send a POST JSON to the /login endpoint.

Correct username and password.

curl -i -H "Content-Type: application/json" \
  -d '{"username":"mkyong","password":"123456"}' \
  -X POST "http://localhost:8080/login"

HTTP/1.1 200
Content-Type: application/json
Transfer-Encoding: chunked
Date: Tue, 23 Aug 2022 09:33:41 GMT

true

Wrong password.

curl -i -H "Content-Type: application/json" \
  -d '{"username":"mkyong"}' \
  -X POST "http://localhost:8080/login"

HTTP/1.1 200
Content-Type: application/json
Transfer-Encoding: chunked
Date: Tue, 23 Aug 2022 09:34:35 GMT

false

2. Spring @RequestBody example – Map version

We also can use @RequestBody to map the request body to the method parameter Map.

package com.mkyong;

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.RestController;

import java.util.Map;

@RestController
public class HelloController {

  @RequestMapping(path = "/v2/login", method = RequestMethod.POST)
  public boolean validateLoginMapVersion(@RequestBody Map<String, String> login) {

      if (login == null) return false;
      String username = login.get("username");
      String password = login.get("password");

      // simple check
      if ("mkyong".equalsIgnoreCase(username) && "123456".equals(password)) {
          return true;
      } else {
          return false;
      }
  }

}

Try to send a POST JSON to the /v2/login endpoint.

Correct username and password.

curl -i -H "Content-Type: application/json" \
  -d '{"username":"mkyong","password":"123456"}' \
  -X POST "http://localhost:8080/v2/login"
  
HTTP/1.1 200

Content-Type: application/json
Transfer-Encoding: chunked
Date: Tue, 23 Aug 2022 09:38:46 GMT

true

Wrong password.

curl -i -H "Content-Type: application/json" \
  -d '{"username":"mkyong","password":"888"}' \
  -X POST "http://localhost:8080/v2/login"   

HTTP/1.1 200
Content-Type: application/json
Transfer-Encoding: chunked
Date: Tue, 23 Aug 2022 09:38:56 GMT

false

3. Download Source Code

4. References

• Spring @RequestBody JavaDoc
• Spring @ResponseBody Annotation
• Spring @Controller and @RestController Annotations
• cURL – Post JSON data to Spring REST