Spring Boot

Email Integration in Spring Boot enables applications to send transactional and notification emails (such as account verifications, password resets, welcome messages, and reports) directly from the backend. Built around the spring-boot-starter-mail starter and the JavaMail / Jakarta Mail API, Spring Boot provides auto-configured mail sender beans (JavaMailSender) to streamline mail creation, server connectivity, and message […]

File download means the server finds a stored file and sends it back to the client as the HTTP response, with headers that tell the client the file name, type, and size. The Content-Disposition header decides whether the browser saves the file (attachment) or opens it (inline). It is used for downloading certificates, marksheets, invoices,

Multiple file upload means a client sends several files in one multipart/form-data request, and Spring Boot receives them together as a List<MultipartFile> (or an array). Each file is a separate part of the request, so the server can check, store, and record every file one by one. It is used when a record needs more

Single file upload means a client sends exactly one file to the server in a multipart/form-data request, and Spring Boot receives it as a MultipartFile. The application then validates the file, saves it somewhere (a folder, the database, or cloud storage), and keeps the file details for later use. It is used for profile pictures,

File Upload and Download in Spring Boot provides mechanisms to receive, store, manage, and transmit binary data (such as documents, images, videos, and PDFs) over HTTP. Built on top of Spring MVC’s multipart resolver support, it enables applications to seamlessly process inbound file data from web or mobile clients and stream files back for download

A standard error response is one fixed JSON structure that your API returns for every kind of failure, whether it is a missing record, invalid input, or a server problem. It is a small class (here ErrorResponse) holding the same fields each time: status, message, timestamp, and request path. It is used so that front-end

Global exception handling means one central class catches the exceptions thrown from every controller in the application and turns them into clean HTTP responses. In Spring Boot you create this class with @RestControllerAdvice, and it holds @ExceptionHandler methods for each kind of error. It is used so that error handling is written once, every API

Controller-level handling means a controller catches and handles exceptions itself, using @ExceptionHandler methods written inside the controller class. When a service throws an exception, Spring looks in that same controller for a matching handler and uses it to build the response. It is used to turn failures such as a missing student or invalid data

A custom exception is your own exception class that describes one specific failure in your application, such as a student who does not exist. It extends RuntimeException (or Exception) and carries a clear name and message, so the problem is obvious in code, logs, and API responses. It is used instead of generic exceptions, because

Exception Handling in Spring Boot is a structured framework for intercepting, managing, and resolving errors that occur during the execution of HTTP requests. Instead of letting unhandled errors crash operations or expose internal stack traces and server details to users, Spring Boot provides mechanisms to catch exceptions gracefully and return meaningful, client-friendly HTTP responses. 1.