Spring @RequestBody Annotation

By Arvind Rai, May 03, 2024

This page will walk through Spring @RequestBody annotation example. The @RequestBody is annotated at method parameter level to indicate that this method parameter will bound to web request body. The consumes attribute of @RequestMapping can specify the media types acceptable to @RequestBody parameter. The @RequestBody can be used with HTTP methods POST, PUT etc. Hence we can use @RequestBody parameter in the methods annotated with @PostMapping and @PutMapping etc.
On this page we will discuss using @RequestBody in detail with complete example.

1. Maven Dependency
2. Using @RequestBody Annotation
3. Complete Example
4. Run Application
5. Reference
6. Download Source Code

1. Maven Dependency

Find the Maven dependency to run the example.

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-web</artifactId>
</dependency>

2. Using @RequestBody Annotation

To use @RequestBody, annotate the method parameter with it.

@PostMapping(value = "book")
public ResponseEntity<Book> addBook(@RequestBody Book book) {
   ------
}

Now the body of web request will be assigned to book parameter.
By default a controller method consumes all media types. We can specify the specific media type to be consumed by @RequestBody. To consume application/json media-type, write code as following.

@PostMapping(value = "book", consumes = { MediaType.APPLICATION_JSON_VALUE })
public ResponseEntity<Book> addBook(@RequestBody Book book) {
   ------
}

To consume application/xml media-type, write code as following.

@PostMapping(value = "book", consumes = { MediaType.APPLICATION_XML_VALUE })
public ResponseEntity<Book> addBook(@RequestBody Book book) {
   ------
}

Find the code snippet to use @RequestBody with HTTP PUT method.

@PutMapping(value = "book", consumes = { MediaType.APPLICATION_JSON_VALUE })
public ResponseEntity<Book> updateBook(@RequestBody Book book) {
   ------
}

Find the code snippet to use @RequestBody to consume byte array.

@PostMapping(value = "send", consumes = { MediaType.APPLICATION_OCTET_STREAM_VALUE })
public String userData(@RequestBody byte[] data) {
   ------
}

3. Complete Example

BookController.java

package com.concretepage.controller;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.util.UriComponentsBuilder;
import com.concretepage.domain.Book;
import com.concretepage.service.BookService;

@RestController
public class BookController {
	@Autowired
	private BookService bookService;

	@PostMapping(value = "book", consumes = { MediaType.APPLICATION_JSON_VALUE })
	public ResponseEntity<Book> addBook(@RequestBody Book book, UriComponentsBuilder builder) {
		bookService.addBook(book);
		HttpHeaders headers = new HttpHeaders();
		headers.setLocation(builder.path("/book/{id}").buildAndExpand(book.getBookId()).toUri());
		return new ResponseEntity<Book>(book, headers, HttpStatus.CREATED);
	}	
	
	@PostMapping(value = "send", consumes = { MediaType.APPLICATION_OCTET_STREAM_VALUE })
	public String userData(@RequestBody byte[] data) {
		bookService.userData(data);
		return "Data sent.";
	}
}

Book.java

package com.concretepage.domain;
public class Book {
	private int bookId;
	private String name;
	private String writer;
        //Setters and Getters
}

BookService.java

package com.concretepage.service;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStream;
import org.springframework.stereotype.Service;
import com.concretepage.domain.Book;

@Service
public class BookService {
	public void addBook(Book book) {
		book.setBookId(101);
	}
	public void userData(byte[] data) {
		InputStream is = new ByteArrayInputStream(data);
		try {
			while (is.available() != 0) {
				System.out.print((char) is.read());
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
}

Find the client code.
RestClientUtil.java

package com.concretepage.client;
import java.io.IOException;
import java.net.URI;
import java.net.URISyntaxException;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.web.client.RestTemplate;
import com.concretepage.domain.Book;
public class RestClientUtil {
	public void addBookDemo() throws URISyntaxException {
		HttpHeaders headers = new HttpHeaders();
		headers.setContentType(MediaType.APPLICATION_JSON);

		URI uri = new URI("http://localhost:8080/book");
		Book book = new Book();
		book.setName("Learning Spring");
		book.setWriter("Krishna");

		HttpEntity<Book> httpEntity = new HttpEntity<Book>(book, headers);

		RestTemplate restTemplate = new RestTemplate();
		ResponseEntity<Book> responseEntity = restTemplate.exchange(uri, HttpMethod.POST, httpEntity,
				Book.class);

		System.out.println("Status Code: " + responseEntity.getStatusCode());
		System.out.println("Location: " + responseEntity.getHeaders().getLocation());
	}
	
	public void sendText() throws URISyntaxException, IOException {
		URI url = new URI("http://localhost:8080/send");
		String msg = "Hello World!";
		HttpEntity<byte[]> requestEntity = new HttpEntity<>(msg.getBytes());
		RestTemplate restTemplate = new RestTemplate();
		ResponseEntity<String> res = restTemplate.postForEntity(url, requestEntity, String.class);
		System.out.println(res.getStatusCodeValue());
		System.out.println(res.getBody());
	}
	public static void main(String args[]) throws URISyntaxException, IOException {
		RestClientUtil util = new RestClientUtil();
		util.addBookDemo();
		util.sendText();		
	}
}