Using @RequestMapping annotation with attribute consumes in Spring MVC

To specify the format that a request can process for a user request, such as the JSON data format, we can use the @RequestMapping annotation with the consumes property in Spring MVC. How is it in details? Let’s find out in this tutorial!

First, I will create a Maven project as an example:

If you do not know how to create the project, just follow the instructions of this tutorial.

I will change default version of the dependencies as follows:

<properties>
    <java-version>1.8</java-version>
    <org.springframework-version>5.0.0.RELEASE</org.springframework-version>
    <org.aspectj-version>1.8.11</org.aspectj-version>
    <org.slf4j-version>1.7.25</org.slf4j-version>
</properties>

<java-version>1.8</java-version>

<org.springframework-version>5.0.0.RELEASE</org.springframework-version>

<org.aspectj-version>1.8.11</org.aspectj-version>

<org.slf4j-version>1.7.25</org.slf4j-version>

</properties>

To run this project, I will use Maven Jetty Plugin:

<plugin>
    <groupId>org.eclipse.jetty</groupId>
    <artifactId>jetty-maven-plugin</artifactId>
    <version>9.4.7.v20170914</version>
</plugin>

<groupId>org.eclipse.jetty</groupId>

<artifactId>jetty-maven-plugin</artifactId>

</plugin>

Now we will define a new Controller locating in the com.huongdanjava.springmvcrequestmapping package, named HelloController. This controller only accepts requests that the data format is JSON. The contents of HelloController are as follows:

package com.huongdanjava.springmvcrequestmapping;

import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
public class HelloController {

	@RequestMapping(value = "/hello", consumes = MediaType.APPLICATION_JSON_VALUE)
	public String hello() {
		return "Hello World!";
	}
}

package com.huongdanjava.springmvcrequestmapping;

import org.springframework.http.MediaType;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

@RestController

public class HelloController {

@RequestMapping(value = "/hello", consumes = MediaType.APPLICATION_JSON_VALUE)

public String hello() {

return "Hello World!";

}

At this point, if you use Postman to request this URL with the GET method and do not transmit anything else, you will get the following result:

To fix this, you must modify the header of the request by adding the Content-Type=application/json attribute. At that point, our request will be free of errors.