Six Common Ways to Read Request Parameters in Spring Boot

When developing APIs with Spring Boot, reading request parameters is a fundamental operation, and Spring Boot offers several mechanisms to satisfy different API design requirements.

@RequestParam

This is the most commonly used annotation for loading parameters that appear after the ? in a URL. For example, the request /user?name=didispace can be handled as follows:

@GetMapping("/user")
@ResponseBody()
public User findUserByName(@RequestParam("name") String name) {
    return userRepo.findByName(name);
}

@PathVariable

Commonly used in RESTful APIs to load parameters embedded in the URL path. For a request like /user/1, you can retrieve the id parameter with:

@GetMapping("/user/{id}")
@ResponseBody()
public User findUserById(@PathVariable("id") String id) {
    return userRepo.findById(id);
}

@MatrixVariable

Less frequently used, but some systems support matrix variables separated by semicolons. For a request such as /books/reviews;isbn=1234;topN=5;, the parameters can be accessed with:

@GetMapping("/books/reviews")
@ResponseBody()
public List<BookReview> getBookReviews(@MatrixVariable String isbn, @MatrixVariable Integer topN) {
    return bookReviewsLogic.getTopNReviewsByIsbn(isbn, topN);
}

@RequestBody

Used to bind the request body of POST/PUT requests, typically for complex payloads. Example of adding multiple accounts:

@PostMapping("/add")
public boolean addAccounts(@RequestBody List<Account> accounts) throws SQLException {
    accounts.stream().forEach(a -> {
        a.setCreatedOn(Timestamp.from(Instant.now()));
        a.setLastLogin(Timestamp.from(Instant.now()));
    });
    return notificationLogic.addAccounts(accounts);
}

@RequestHeader

Loads data from HTTP request headers, often used for infrastructure concerns such as passing a TraceID. Example of reading an Authorization header:

@GetMapping("/user")
@ResponseBody()
public List<User> getUserList(@RequestHeader("Authorization") String authToken) {
    return userRepo.findAll();
}

@CookieValue

Retrieves values from cookies, useful for stateful interactions. Example of reading a SessionId cookie:

@GetMapping("/user")
@ResponseBody()
public List<User> getUserList(@CookieValue(name = "SessionId") String sessionId) {
    return userRepo.findAll();
}

The article concludes after presenting these six annotation-based methods for handling request parameters in Spring Boot.