Internal working of Spring

Spring is popular for its auto-configuration feature. It means it automatically configures our application based on the added dependencies during the project creation. Beans are stored in IoC container. Spring will look for main class with SpringApplication.run method and annotated with @SpringBootApplication. @SpringBootApplication is the combination of three annotations.

  1. @ComponentScan: Also called user configuration which is first step or phase. It detects and registers spring managed components (@Controller, @Service, @Repository, @RestController etc) with Application Context. @ComponentScan without arguments tells the Spring to scan the current package and the sub-packages.
  2. @EnableAutoConfiguration: Auto-configuration phase. It enables the Spring to auto-configure the application context. Therefore it automatically creates and registers beans based on jars in the classpath and the beans defined by the user.
  3. @Configure: Indicates the annotated class declares one or more beans definition or configuration methods. 

When the client makes a request, it reaches the dispatcher servlet which is the front controller. Dispatcher servlet consults the HandlerMapping which maps to a specific controller and forwards the request. Controller processes the request by invoking business logic or service and response is generated which is send back to the client. 

In SpringMVC, the controller prepares a model object which contains data to be displayed by the view. The controller sends a logical view name to the Dispatcher Servlet. Dispatcher Servlet resolves this to actual view implementation. Once view is resolved, Dispatcher Servlet invokes view to render the response. Finally rendered view is send back to the client.

Comments

Post a Comment

Popular posts from this blog

Transform values with a stream

The goal is to transform an array of numbers into a comma-delimited string using functional programming. The code snippet you provided has a minor issue: String.join(",", strings[0]) is incorrect because it tries to join a single element ( strings[0] ) rather than all elements in the strings array. Here's the corrected code for the transformValues method: import java.util.Arrays; class Answer {     // Change these boolean values to control whether you see      // the expected answer and/or hints.     static boolean showExpectedResult = true;     static boolean showHints = true;     // Transform an array of numbers into a comma-delimited list     // using functional programming.     static String transformValues(int[] numbers) {         // Convert the int array to a stream of integers         // Map each integer to its String representation         // ...
Read more

Collections Framework

 The Java Collections Framework provides a comprehensive set of interfaces, implementations, and algorithms to work with collections of objects in Java. It offers a unified architecture for representing and manipulating collections, making it easier to work with data structures in Java programs. The Collections Framework is a fundamental part of Java programming and is widely used in various applications ranging from simple data manipulation tasks to complex algorithms and data processing pipelines.  Key components of the Collections Framework: Interfaces Collection : The root interface of the Collections Framework hierarchy. Represents a group of objects, known as elements. Subinterfaces include List , Set , and Queue . List : Represents an ordered collection of elements where duplicate elements are allowed. Allows elements to be accessed and inserted by index. Implementations include ArrayList , LinkedList , and Vector . Set : Represents a collection of unique elements ...
Read more

Inspect a collection

Calculate the cart total  import java.util.List; import java.util.concurrent.atomic.AtomicReference; public class Main {     public static void main(String[] args) {         List<Item> items = List.of(             new Item("Item1", 10.0f, 2),             new Item("Item2", 5.0f, 4),             new Item("Item3", 20.0f, 1)         );         float total = getCartTotal(items);         System.out.println("Cart Total: " + total);  // Output: Cart Total: 60.0     }     static float getCartTotal(List<Item> items) {         AtomicReference<Float> total = new AtomicReference<>(0.0f);         items.forEach(item -> {             total.updateAndGet(v -> v + item.getQuantity() * item.getPrice())...
Read more