{"id":7908,"date":"2025-03-12T10:50:20","date_gmt":"2025-03-12T10:50:20","guid":{"rendered":"https:\/\/msgprogramator.sk\/?p=7908"},"modified":"2026-04-01T11:55:27","modified_gmt":"2026-04-01T11:55:27","slug":"hello-world-java","status":"publish","type":"post","link":"https:\/\/msgprogramator.sk\/en\/hello-world-java\/","title":{"rendered":"Hello World or your first Java application (tutorial)"},"content":{"rendered":"

Do you want to program your first Hello World Java application but don’t know how to get started? This article walks you step-by-step through creating your first hello world Java program called TimeNow<\/em>, which displays the current date and time. <\/strong><\/p>\n

Usually, the first lesson in programming is to deal with listing the Hello World!<\/strong> greeting to the console. And since I like original ideas, as the first Java application<\/strong> we will create a TimeNow program that will work like a digital watch – it will print the current date and exact time when the program is started. Whether you’re a beginner or a programmer<\/a>, still in school or already working, everyone can do it with our tutorial. So let’s get started!<\/p>\n

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Basically, it is the simplest possible program that demonstrates how to write, translate and run code in a given language. Hello world programs are also useful for verifying that the development environment is properly installed and working.<\/p>\n

Preparing for Java application development<\/h2>\n

In order to start developing Java applications, we first need to download and install two basic programs:<\/p>\n

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  1. JDK<\/strong> (Java Development Kit) – contains the tools needed to compile and run Java programs.<\/li>\n
  2. Development environment (IDE)<\/strong> – provides a comfortable environment for writing code, testing it and easy launching of programs without complicated settings. In addition, it automatically highlights errors in the code and offers suggestions for fixes.<\/li>\n<\/ol>\n

    For Java, we have several environments to choose from. The most well-known development environments (IDEs) include IntelliJ IDEA, Eclipse and Netbeans.<\/p>\n

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    <\/div>\n<\/div>\n

    Whichever one you choose, after installing the JDK and the development environment following our instructions, you’re ready to start programming in Java. The following procedure is the same for all environments. The images used are from the IntelliJ IDEA development environment.<\/p>\n

    Creating a new Java project<\/h2>\n
      \n
    1. Start your installed development environment.<\/li>\n
    2. If the welcome screen opens, click on New Project – New Project<\/em>. Otherwise, go to the main menu File -> New Project<\/em>.<\/li>\n
    3. In the New Project<\/em> window, select Java<\/em> from the list on the left.<\/li>\n
    4. Name your project, e.g. \u201cTimeNow\u201d.<\/em><\/li>\n
    5. Make sure you have the JDK installed and see the latest version there.<\/li>\n
    6. Uncheck Add sample code. <\/em>You won’t need the sample code, you can create your own.<\/li>\n
    7. Check the following picture to see if you have followed the correct procedure. If everything is as you see below, click the Create<\/em> button and the IDE will create and load a new Java project.<\/li>\n<\/ol>\n

      Creating a new project in the IntelliJ IDEA development environment<\/em><\/p>\n

      \"Creating<\/p>\n

      Empty Java project in IntelliJ IDEA development environment<\/em><\/p>\n

      \"Empty<\/p>\n

      Creating the first Java class<\/h2>\n

      1. Right-click on the src tab and select New -> Java class<\/em> from the context menu.<\/strong><\/p>\n

      \"1.<\/p>\n

      2. For example, name it \u201cMain\u201d<\/em> and press Enter.<\/strong><\/p>\n

      \"For<\/p>\n

      3. IntelliJ creates the Main.java file.<\/strong><\/p>\n

      \"IntelliJ<\/p>\n

      4. Edit this file as follows. Feel free to copy this code and explain each line. <\/strong><\/p>\n

      1.\timport java.time.LocalDateTime;\n2.\timport java.time.format.DateTimeFormatter;\n3.\t\n4.\tpublic class Main {\n5.\t    public static void main(String[] args) {\n6.\t        DateTimeFormatter formatovacCasu = DateTimeFormatter.ofPattern("dd.MM.yyyy HH:mm:ss");\n7.\t        LocalDateTime teraz = LocalDateTime.now();\n8.\t        String formatovanyCas = teraz.format(formatovacCasu);\n9.\t        System.out.println("Presn\u00fd \u010das je: " + formatovanyCas);\n10.\t    }\n11.\t}<\/code><\/pre>\n
       <\/p>\n
      This is what the resulting TimeNow \u201cHello World\u201d application looks like in Java<\/strong><\/p>\n
      \"This<\/p>\n
      Explaining the code of your first Java application<\/h2>\n