Spring Boot YAML Configuration
Introduction: In this quick tutorial, we’ll learn how to use a YAML file to configure properties of a Spring Boot application. What is YAML File? Instead of having an application.properties in Spring, we can use the application.yml as our configuration file. YAML is a superset of JSON and we can use it for configuring data. The […]
Spring ClassPathXmlApplicationContext
Introduction: Spring provides two types of containers: BeanFactory: It supports bean instantiating and wiring ApplicationContext: It extends the BeanFactory and so provides all those features as that a BeanFactory. Additionally, it provides automatic registration of BeanPostProcessor, internationalization, and many more features The Spring container is responsible for instantiating and managing the lifecycle of Spring beans. […]
Spring Dependency Injection
Introduction: In a well-designed Java application, the classes should be as independent as possible. Such a design promotes reusability of components. It also makes it easier to unit test the various components. The concept of dependency injection promotes loose coupling among Java objects. In this tutorial, we’ll talk about the dependency injection in Spring framework. […]
Spring @Value Annotation
Introduction: Spring @Value annotation is used to inject values into variables and method arguments. We can either read spring environment variables or system variables. It also supports SpEL. In this quick tutorial, we’ll explore how to work with Spring @Value annotation. Setup: Let’s start by first defining a few properties in our app.properties file: user.first.name=Sam […]
Spring MVC Annotations
Introduction: Spring 2.5 onwards, we can use annotations to mark our Spring components. One way of doing so is to use a <component-scan> tag in our appConfig.xml: <context:component-scan base-package="com.programmergirl" /> The Spring container will then recursively scan all components in the given package & its sub-packages. In this quick tutorial, we’ll discuss the most commonly […]
Spring Boot Exit Codes – Create Custom Exit Code
Introduction: When running a Spring Boot application, we get a system exit code of 0, when everything goes fine. For any unhandled exceptions, the application returns with an exit code 1. It’s possible for us to return a custom exit code from our Spring Boot application. In this tutorial, we’ll learn to do so. Implementing […]
Using @ResponseStatus for Http Status in Spring
Introduction: In Spring MVC, we can set the status of the HttpResponse in several ways. In this tutorial, we’ll achieve it using the @ResponseStatus annotation. We can use @ResponseStatus to mark a method or an exception class with a status code and reason that should be returned. On invoking the marked handler method or when […]
@Component vs @Repository vs @Service in Spring
Introduction: With Spring’s auto-scanning feature, it automatically detects various beans defined in our application. We usually annotate our beans using one of the available Spring annotations – @Component, @Repository, @Service, @Controller. On detecting the bean, Spring simply registers it into the ApplicationContext. In this quick tutorial, we’ll look at the difference between @Component, @Repository, and, […]
Spring Core Annotations
Introduction: Spring annotations present in the org.springframework.beans.factory.annotation and org.springframework.context.annotation packages are commonly known as Spring Core annotations. We can divide them into two broad categories: DI-Related Annotations & Context Configuration Annotations: In this tutorial, we’ll explore all of these Spring Core annotations. DI-Related Annotations: 1. @Autowired: We use @Autowired to mark the dependency which […]
Spring MVC @Controller vs @RestController Annotation
Introduction: In this tutorial, we’ll look at the difference between @Controller and @RestController annotations in Spring MVC. The @Controller annotation has been part of the Spring framework from the very beginning. As its name suggests, it defines a controller: an entry-point for a Spring Web application. Spring 4 introduced a @RestController annotation. It is a […]