Spring Boot Tutorial

Spring Boot - Software Setup and Configuration (STS/Eclipse/IntelliJ)

Prerequisite (Spring Core Concepts)

Spring Boot Core

Spring Boot with REST API

Spring Boot with Database and Data JPA

Spring Boot with Kafka

Spring Boot with AOP

How to Get the Body of Request in Spring Boot?

In a Spring Boot application, when you're handling HTTP requests in your controllers, you can access the body of a request using the @RequestBody annotation.

Here's how you can achieve that:

1. Define a Model Class (optional):

For structured data like JSON or XML, you typically create a model class that matches the structure of the request body.

For example, consider a JSON request body for creating a user:

{
    "name": "John",
    "age": 25
}

You could define a corresponding model class:

public class User {
    private String name;
    private int age;

    // Getters, setters, and other methods...
}

2. Use `@RequestBody` in your Controller:

Now, in your controller, you can annotate a method parameter with @RequestBody to let Spring automatically deserialize the request body into your model class:

@RestController
public class UserController {

    @PostMapping("/users")
    public ResponseEntity<String> createUser(@RequestBody User user) {
        // Your logic here...

        return ResponseEntity.ok("User created successfully!");
    }
}

3. For Raw Data:

If you want to read raw data from the request body, you can use @RequestBody with a String parameter:

@PostMapping("/rawdata")
public ResponseEntity<String> handleRawData(@RequestBody String rawData) {
    // rawData contains the raw request body
    return ResponseEntity.ok("Data received successfully!");
}

4. Configuring the Message Converters (if necessary):

Spring Boot automatically configures message converters based on the dependencies present in your project. If you have Jackson on your classpath, Spring Boot will use it to handle JSON content by default. If you need to customize the deserialization process, you might need to configure the message converters accordingly.

Notes:

Ensure you have the necessary dependencies on your classpath. For handling JSON, you usually have the spring-boot-starter-web dependency, which includes Jackson by default.
If a client sends a malformed request body or a body that can't be deserialized into your model class, Spring will return a 400 Bad Request response.
@RequestBody is used to indicate that method parameter should be bound to the value of the HTTP request body. Spring's HttpMessageConverter takes care of the deserialization process.

Accessing request body in Spring Boot controller:

Description: Retrieve the entire request body in a Spring Boot controller.

Java Code:

@PostMapping("/example")
public ResponseEntity<String> handleRequestBody(@RequestBody String requestBody) {
    // Process the request body
    return ResponseEntity.ok("Request body received: " + requestBody);
}

Reading request body content in Spring Boot REST API:

Description: Read and process the content of the request body in a Spring Boot REST API.

Java Code:

@PostMapping("/api/data")
public ResponseEntity<String> processRequestBody(@RequestBody DataModel data) {
    // Process data from the request body
    return ResponseEntity.ok("Data processed: " + data.toString());
}

Extracting JSON or XML payload from Spring Boot request:

Description: Extract JSON or XML payload from the request body in Spring Boot.

Java Code:

@PostMapping("/api/payload")
public ResponseEntity<String> processPayload(@RequestBody String payload) {
    // Extract and process JSON or XML payload
    return ResponseEntity.ok("Payload processed: " + payload);
}

Handling POST request body in Spring Boot:

Description: Handle the POST request body in a Spring Boot controller method.

Java Code:

@PostMapping("/api/post")
public ResponseEntity<String> handlePostRequestBody(@RequestBody String requestBody) {
    // Process the POST request body
    return ResponseEntity.ok("POST request body received: " + requestBody);
}

Retrieving form data from request body in Spring Boot:

Description: Retrieve form data from the request body in a Spring Boot controller.

Java Code:

@PostMapping("/api/form")
public ResponseEntity<String> handleFormData(@RequestBody MultiValueMap<String, String> formData) {
    // Process form data from the request body
    return ResponseEntity.ok("Form data processed: " + formData.toString());
}

Accessing raw request body in Spring Boot filter:

Description: Access the raw request body in a Spring Boot filter.

Java Code (Filter):

public class RawRequestBodyFilter extends OncePerRequestFilter {
    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
        String rawRequestBody = extractRawRequestBody(request);
        // Process the raw request body
        filterChain.doFilter(request, response);
    }
}

Parsing and processing request body in Spring Boot interceptor:

Description: Parse and process the request body in a Spring Boot interceptor.

Java Code (Interceptor):

public class RequestBodyInterceptor extends HandlerInterceptorAdapter {
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        String requestBody = extractRequestBody(request);
        // Process the request body
        return true;
    }
}

Reading request body in Spring Boot servlet filter:

Description: Read the request body in a Spring Boot servlet filter.

Java Code (Filter):

public class RequestBodyLoggingFilter extends OncePerRequestFilter {
    @Override
    protected void doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) throws ServletException, IOException {
        String requestBody = extractRequestBody(request);
        // Log or process the request body
        filterChain.doFilter(request, response);
    }
}

Getting request body in Spring Boot RESTful service:

Description: Retrieve the request body in a Spring Boot RESTful service.

Java Code:

@PostMapping("/api/service")
public ResponseEntity<String> handleServiceRequest(@RequestBody String requestBody) {
    // Process the request body in a service
    return ResponseEntity.ok("Request body processed in the service: " + requestBody);
}

Processing multipart form data in Spring Boot request body:

Description: Handle and process multipart form data in the request body.

Java Code:

@PostMapping("/api/multipart")
public ResponseEntity<String> handleMultipartFormData(@RequestPart("file") MultipartFile file, @RequestPart("data") String data) {
    // Process multipart form data
    return ResponseEntity.ok("Multipart form data processed: " + data);
}

Handling different content types in Spring Boot request body:

Description: Handle various content types (JSON, XML, form data) in the request body.

Java Code:

@PostMapping("/api/content-type")
public ResponseEntity<String> handleDifferentContentTypes(@RequestBody Object requestBody) {
    // Process request body based on content type
    return ResponseEntity.ok("Request body processed: " + requestBody.toString());
}

Customizing request body processing in Spring Boot:

Description: Customize how Spring Boot processes the request body.

Java Code:

@Configuration
public class RequestBodyConfiguration extends WebMvcConfigurerAdapter {
    @Override
    public void configureMessageConverters(List<HttpMessageConverter<?>> converters) {
        // Customize message converters for request body processing
    }
}

Using @RequestBody annotation in Spring Boot controllers:

Description: Utilize the @RequestBody annotation to bind the request body to a method parameter.

Java Code:

@PostMapping("/api/annotation")
public ResponseEntity<String> handleRequestBodyAnnotation(@RequestBody DataModel data) {
    // Process data from the request body using @RequestBody
    return ResponseEntity.ok("Data processed: " + data.toString());
}

Parsing and validating JSON request body in Spring Boot:

Description: Parse and validate JSON data in the request body of a Spring Boot controller.

Java Code:

@PostMapping("/api/json")
public ResponseEntity<String> handleJsonRequestBody(@Valid @RequestBody JsonModel jsonModel, BindingResult result) {
    // Process and validate JSON request body
    return ResponseEntity.ok("JSON data processed: " + jsonModel.toString());
}

Accessing request body parameters in Spring Boot:

Description: Access parameters within the request body in a Spring Boot controller.

Java Code:

@PostMapping("/api/parameters")
public ResponseEntity<String> handleRequestBodyParameters(@RequestParam("param1") String param1, @RequestParam("param2") int param2) {
    // Process parameters from the request body
    return ResponseEntity.ok("Parameters processed: " + param1 + ", " + param2);
}

Reading request body as InputStream in Spring Boot:

Description: Read the request body as an InputStream in a Spring Boot controller.

Java Code:

@PostMapping("/api/inputstream")
public ResponseEntity<String> handleInputStreamRequestBody(InputStream requestBody) {
    // Process InputStream from the request body
    return ResponseEntity.ok("InputStream processed");
}

Handling binary data in request body with Spring Boot:

Description: Handle binary data in the request body of a Spring Boot controller.

Java Code:

@PostMapping("/api/binary")
public ResponseEntity<String> handleBinaryData(@RequestBody byte[] binaryData) {
    // Process binary data from the request body
    return ResponseEntity.ok("Binary data processed");
}

Consuming XML payload from request body in Spring Boot:

Description: Consume XML payload from the request body in a Spring Boot controller.

Java Code:

@PostMapping("/api/xml")
public ResponseEntity<String> handleXmlPayload(@RequestBody XmlModel xmlModel) {
    // Process XML payload from the request body
    return ResponseEntity.ok("XML payload processed: " + xmlModel.toString());
}

Configuring request body logging in Spring Boot:
- Description: Configure logging for request bodies in Spring Boot for debugging or analysis.
- Java Code:
```
@Bean
public Filter requestLoggingFilter() {
    return new RequestLoggingFilter();
}
```

How to Get the Body of Request in Spring Boot?

1. Define a Model Class (optional):

2. Use @RequestBody in your Controller:

3. For Raw Data:

4. Configuring the Message Converters (if necessary):

Notes:

2. Use `@RequestBody` in your Controller: