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8.9 KiB
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{"/courses/prog-intro/lectures/intro/":{"data":{"what-does-java-consist-of#What does Java consist of?":"Java consists of multiple main components. The first one being the Java compiler. The process of converting human-readable text to machine code is called compilation.\nImg.2 - Simplified Compilation Process","why-do-we-choose-java#Why do we choose Java?":"Why do we choose Java?According to TIOBE Programming Community Index Java is one of the most demanded languages in the programming field.\nImg. 1 - TIOBE Programming Community Index\nAlso, Java has a lot of advantages for beginners such as:\nIt’s fairly easy It has a broad spectre of usage Server Desktop Mobile devices Smart-cards"},"title":"Lecture 1. Introduction"},"/courses/spring-boot/":{"data":{"configuring-application-properties#Configuring Application Properties":"Let’s take a look at our application.properties file located at src/main/resources/application.properties.\nspring.application.name=store To use this property in our code we can use the @Value annotation.\nLet’s change our HomeController class so it prints the name of our application.\npackage us.fymio.store; import org.springframework.beans.factory.annotation.Value; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; @Controller public class HomeController { @Value(\"${spring.application.name}\") private String appName; @RequestMapping(\"/\") // this represents the root of our website public String index() { System.out.println(\"application name = \" + appName); return \"index.html\"; // this returns the view } } And as we can see after running our application there is a store printed out in the terminal.\n... 2026-02-19T15:32:37.507+03:00 INFO 41536 --- [store] [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Initializing Servlet 'dispatcherServlet' 2026-02-19T15:32:37.509+03:00 INFO 41536 --- [store] [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Completed initialization in 2 ms application name = store ...","controllers#Controllers":"Spring MVC stands for Model View Controller.\nModel is where our application’s data lives. It represents the business logic and is usually connected to a database or other data sources. In spring boot the model can be a simple java class.\nView is what the user sees. It’s the HTML, CSS or JavaScript that’s rendered in the browser. In Spring MVC views can be static files or dynamically generated.\nController is like a traffic controller. It handles incoming requests from the user, interacts with the model to get data and then tells the view what to display.\nLet’s add a new java class called HomeController. It will be located at src/main/java/us/fymio/store/HomeController.java.\npackage us.fymio.store; public class HomeController {} To make this a controller we have to decorate it with the controller annotation. And import the Controller from org.springframework.stereotype package.\npackage us.fymio.store; import org.springframework.stereotype.Controller; @Controller public class HomeController {} Let’s now add an index method. When we send a request to the root of our website we want this method to be called. Also we need to add another special annotation to this method.\npackage us.fymio.store; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.RequestMapping; @Controller public class HomeController { @RequestMapping(\"/\") // this represents the root of our website public String index() { return \"index.html\"; // this returns the view } } Now we need to create this view. We add the index.html at src/main/resources/static/index.html. For now let’s just print “Hello world!”.\n\u003c!doctype html\u003e \u003chtml lang=\"en\"\u003e \u003chead\u003e \u003cmeta charset=\"UTF-8\" /\u003e \u003cmeta name=\"viewport\" content=\"width=device-width, initial-scale=1.0\" /\u003e \u003ctitle\u003eView\u003c/title\u003e \u003c/head\u003e \u003cbody\u003e \u003ch1\u003eHello world!\u003c/h1\u003e \u003c/body\u003e \u003c/html\u003e Now let’s build our application using mvn spring-boot:run.\nAs we can see from the logs:\n2026-02-19T14:55:23.948+03:00 INFO 36752 --- [store] [ main] o.s.boot.tomcat.TomcatWebServer : Tomcat initialized with port 8080 (http) It means that our app is up and running at localhost:8080.\nImg. 7 – Our app is up and running!","dependency-injection#Dependency injection":"Imagine we are building an E-Commerce application that handles placing orders. When the order is placed, the customer’s payment needs to be processed so order service depends on a payment service like stripe payment service. In this case we can say that order service is dependent or coupled to stripe payment service.\nImg. 8 – Depends On/Coupled To relation.","dependency-management#Dependency Management":"Dependencies are third-party libraries or frameworks we use in our application. For example to build a web application we need an embedded web server like Tomcat, we need libraries for handling web requests building APIs, processing JSON data, logging and so on.\nIn spring boot applications instead of adding multiple individual libraries we can use a starter dependency.\nImg. 5 – Spring Boot Starter Web\nTo use this dependency we just need to copy the code below to our pom.xml file.\norg.springframework.boot spring-boot-starter-web 4.1.0-M1 So the dependencies section would look like this\norg.springframework.boot spring-boot-starter org.springframework.boot spring-boot-starter-test test org.springframework.boot spring-boot-starter-web Notice, that I commented out the version of our dependency. That’s because it’s a better practice to let Spring Boot decide what version of the dependency to use.","initialize-spring-boot-project#Initialize Spring Boot Project":"To initialize a new spring boot project you can go to start.spring.io and select options that suits you.\nImg. 3 – Spring Boot options\nAfter unpacking the zip arvhive we have this template project.\n. ├── HELP.md ├── mvnw ├── mvnw.cmd ├── pom.xml ├── src │ ├── main │ │ ├── java │ │ │ └── us │ │ │ └── fymio │ │ │ └── store │ │ │ └── StoreApplication.java │ │ └── resources │ │ └── application.properties │ └── test │ └── java │ └── us │ └── fymio │ └── store │ └── StoreApplicationTests.java └── target ├── classes │ ├── application.properties │ └── us │ └── fymio │ └── store │ └── StoreApplication.class ├── generated-sources │ └── annotations ├── generated-test-sources │ └── test-annotations ├── maven-status │ └── maven-compiler-plugin │ ├── compile │ │ └── default-compile │ │ ├── createdFiles.lst │ │ └── inputFiles.lst │ └── testCompile │ └── default-testCompile │ ├── createdFiles.lst │ └── inputFiles.lst ├── surefire-reports │ ├── TEST-us.fymio.store.StoreApplicationTests.xml │ └── us.fymio.store.StoreApplicationTests.txt └── test-classes └── us └── fymio └── store └── StoreApplicationTests.class The “heart” of our project is the file named pom.xml:\n\u003c?xml version=\"1.0\" encoding=\"UTF-8\" ?\u003e","prerequisites#Prerequisites":"Prerequisites Solid understanding of Java Object-oriented programming Classes, methods and interfaces Basic understanding of databases Tables, primary keys, foreign keys, relationships, etc. Write basic SQL statements","what-is-a-spring-framework#What is a Spring Framework?":"Spring – is a popular framework for building Java applications. It has a lot of modules, each designed to handle a specific task. They are combined into few different layers.\nImg. 1 – Spring layers\nLayer Purpose Core Handling dependency injection, managing objects Web Building web applications Data Working with databases AOP Aspect oriented programming Test Testing spring components While the spring framework is powerfull, using it often involves a lot of configuration. For example, if you want to build a web app you might need to setup a web server, configure routing and manage dependencies manually. That’s when Spring Boot comes in.\nYou can think of spring boot as a layer on top of the spring framework, that takes care of all of the setup.\nSring Boot siplifies Spring development by providing sensible defaults and ready-to-use features.\nBy the way, the spring framework is just one part of a larger family of projects in the spring ecosystem.\nImg. 2 – Spring ecosystem\nModule Name Purpose Spring Data Simplifying database access Spring Security Adding authentication and authorization Spring Batch Batch processing Spring Cloud Building microservices and distributed systems Spring Integration Symplifying messaging and integration between systems"},"title":"_index"}} |