How to Get the Body of Request in Spring Boot?

In Spring Boot, handling client requests is a common task when building REST APIs. Developers often need to read the request body sent by the client to process data such as JSON or form inputs.

• Spring Boot provides annotations to easily access data sent in HTTP requests.
• The request body usually contains JSON or XML data sent by the client.

@RequestBody

@RequestBody is an annotation in Spring MVC used to bind the HTTP request body to a method parameter in a controller. It automatically converts incoming JSON data into a Java object.

• Maps JSON data from the request body to a Java object.
• Commonly used in POST and PUT requests to receive client data.

Syntax

@RequestBody: Annotation is used to get the request body in the incoming request.

Step-By-Step Implementation

Step 1: Create a Spring Boot Project

Generate a project using Spring Initializr and include the Spring Boot web dependency. Fill in the details as per the requirements. For this application:

• Project: Maven
• Language: Java
• Spring Boot: 2.2.8
• Packaging: JAR
• Java: 8
• Dependencies: Spring Web

Click on Generate which will download the starter project.

Extract the ZIP file and open your preferred IDE. Then navigate to File → New → Project from Existing Sources, select the Spring Boot project folder, and choose the pom.xml file. Import the project and wait for the dependencies to sync.

Note: In the Import Project for Maven window, make sure you choose the same version of JDK which you selected while creating the project.

Step 2 Create Entity Class

Create a class named Person inside -> src/main/java/com/example/demo.

Person.java

This class represents the data that will be received from the request body.

Step 3: Create Controller

Create a controller class and use the @RequestBody annotation to read the request body.

Controller.java

Here, the Person object is automatically created by Spring using the JSON data received in the request body.

Step 4: Run main class

Run the main Spring Boot application class and wait for the embedded Tomcat server to start.

By default, the application runs on:

http://localhost:8080

Note: The default port 8080 can be changed in the application.properties file.

Step 5: Send Request Using Postman

Open Postman and send a POST request to

http://localhost:8080/person

Request Body (JSON)

{

"id": 1,

"name": "Aayush",

"age": 32

}

Output:

The received data will be printed in the terminal/console:

1 Aayush 32