cristianprofile / spring-mvc-functional

Testing new spring-mvc-functional

Testing new WebMvc.fn model in Spring mvc

Testing new WebMvc.fn programming model in Spring MVC. Better approach to get more functional definition of controllers using route. (similar to webflux module)

GET localhost:8080/transaction   ---> get all transactions

GET localhost:8080/transaction/1 ----> get transaction with id 1

GET localhost:8080/transaction/2222 ----> throw exception http response 204 (No content)

GET localhost:8080/transaction   ---> get all transactions

POST localhost:8080/transaction   ---> create a transactions

Router configuration:

 @Bean
 RouterFunction<ServerResponse> routes(TransactionHandler transactionHandler) {
    var root = "";
    return route()
            .GET(root + "/transaction", transactionHandler::handleGetAllTransaction)
            .GET(root + "/transaction/{id}", transactionHandler::handleGetTransactionById).
                    POST(root + "/transaction", transactionHandler::handlePostTransaction).

            //Defined Exception handler behaviour code:
            onError(IllegalArgumentException.class, this::catchNullPointerException).
            onError(NullPointerException.class, this::catchIllegalArgumentException).
            // Define filter
            filter(this::filterHandler)
            
            .build();
}

Code Filtering request:

private ServerResponse filterHandler(ServerRequest serverRequest, HandlerFunction<ServerResponse> handlerFunction) throws Exception {
    try {
        logger.info("Init HandlerFilterFunction");
        return handlerFunction.handle(serverRequest);
    } finally {
        logger.info("End HandlerFilterFunction");
    }
}

Defined Exception handler behaviour code:

private ServerResponse catchIllegalArgumentException(Throwable error, ServerRequest request) {
    logger.error("Error message NullPointer Exception: {}", error.getMessage());
    return ServerResponse.status(HttpStatus.NOT_ACCEPTABLE).build();
}

private ServerResponse catchNullPointerException(Throwable error, ServerRequest request) {
    logger.error("Error message IllegalArgumentException: {}", error.getMessage(), error);
    return ServerResponse.status(HttpStatus.NO_CONTENT).build();
}

Transaction handler configuration (controller code using ServerResponse builder):

public TransactionHandler(TransactionService transactionService) {
    this.transactionService = transactionService;
}

ServerResponse handleGetAllTransaction(ServerRequest serverRequest) {
    return ok().body(transactionService.getAll());
}

ServerResponse handlePostTransaction(ServerRequest request) throws ServletException, IOException {
    Transaction transaction = request.body(Transaction.class);
    var result = transactionService.save(transaction);
    var uri = URI.create("/transaction/" + result.getId());
    return ServerResponse.created(uri).body(result);
}

ServerResponse handleGetTransactionById(ServerRequest r) {
    return ok().body(transactionService.findById(Long.parseLong(r.pathVariable("id"))));
}