Daemon tools are similar programs. Free analogues of paid programs for Windows. More about functions

Java is an object-oriented programming language created by James Gosling in 1995, which means expressing variables as objects with fields (which are attributes that describe an object) and methods (actions that an object can perform). Java is a language that allows you to write programs that can run under any Java virtual machine. Since this is a rather voluminous programming language in terms of the number of words, it is quite simple to understand and learn even for beginners. This tutorial provides an introduction to Java programming.

Steps

Writing your first Java program

To get started writing Java programs, first install the development environment. Many programmers use an integrated development environment (eng. Integrated development environment- IDE) such as Eclipse or Netbeans, but you can create a program without it.

Any program like Notepad will suffice for Java programming. Some programmers prefer to use text editors based on vim and emacs. There is also a fairly good text editor that can be installed on both Windows and Linux (Mac, Ubuntu and so on) - Sublime Text. We will use it in this review.

Make sure you have the Java Java Development Kit installed. You will need it to compile your program.

• If your computer is running a Windows operating system and the variable environment is not working properly, it may throw a javac. Read to get more detailed installation information to eliminate this error.

Hello World Program

1. First, we will create a program that will print Hello World. Create a new file in a text editor and save it as "HelloWorld.java". "HelloWorld" is the name of the class, which must be the same as the file name, this is important.

   Set the class and main method. The main method public static void main (String args) will be applied every time the program starts and will be installed in every subsequent Java program.

   public class HelloWorld (public static void main (String args) ())

   Enter the line of code "Hello World."

   System. out. println ("Hello World.");

   • Consider the components of this line of code:
     • System tells the system to perform certain actions.
     • Out tells the system that we are about to enter some data.
     • Println input string - tells the system to display the value on the screen.
     • The parentheses around ("Hello World") indicate that the System.out.println () method takes that value as a parameter.
   • Take note of a few rules to follow when coding in Java:
     • At the end of each line of code, you must put a semicolon.
     • Java is case sensitive, so the values ​​of the method, variables, and class name must be written with respect to it.
     • The blocks of code that refer to a particular method are separated by curly braces.
2. Put it all together. Ultimately, your Hello World program should look like this:

   public class HelloWorld (public static void main (String args) (System.out.println ("Hello World.");))

3. Save the file and open a command prompt or terminal to compile the program. Go to the folder where you saved the HelloWorld.java file and enter HelloWorld.java into Javac (the optimizing java compiler). This way, you let the compiler know that you want to convert the file. If errors pop up in the process, the compiler will notify you what you did wrong. Ideally, you shouldn't have any notifications from the compiler at all while converting the file. When the compilation is complete, look in the folder where the HelloWorld.java file was saved - the HelloWorld.class file should appear there. This is what the Java virtual machine will use to start.
4. Run the program. Finally we got to this point! At the command line or terminal, enter in java HelloWorld. The virtual machine will understand that you want to run the HelloWorld class. The console should display HelloWorld.
5. Congratulations, you have created your first Java program.

Input and Output

1. Now we need to extend our Hello World program to accept user input. In our program, we printed a string that is visible to the user, but in interactive programs, users enter data in applications. Our goal is to extend the program so that it prompts the user for a name and then greets them by name.
2. Import the Scanner class. Java has built-in libraries that we have access to, but we need to import them. One of these libraries is java.util, which contains a Scanner object that we need for user input. In order to import this class, we need to add the following line to the source code.

   Import java.util.Scanner;

   • This tells the program that we want to use the Scanner object that exists in the java.util package.
   • If we want to access all the objects in the java.util. Library, we just need to import java.util. * At the beginning of the code.
3. You need to introduce a new variable in the method for the Scanner object. Java is an object-oriented programming language that operates on variables through objects. A scanner is an example of an object that has fields and methods. In order to use the Scanner class, we need to create a new Scanner object with which we can fill in the fields. To do this, we prescribe the following:

   Scanner userInputScanner = new Scanner (System.in);

   • userInputScanner is the name of the scanner object we just set up. Take note that the name is written in a "humpbacked case". This is the convention for using variable names in Java.
   • We use a new operator to create a new instance of an object. In our case, we have created a new instance of the Scanner object by specifying new Scanner (System.in) in the code.
   • The Scanner object picks up a parameter telling the object to scan. In this case, System.in is the parameter. System.in tells the program to scan user-entered data.
4. The next step is to make it clear for the user to enter data in the console. This can be done using the System.out.print or System.out.println command.

   System.out.print ("What" s your name? ");

5. Make the Scanner object pick up the next line the user enters and store it as a variable. Scanner should always collect user input data. The following line of code will instruct the Scanner object to recognize the user-written name and store it as a variable:

   String userInputName = userInputScanner.nextLine ();

   • In Java, the confirmation of using an object method is specified by the parameters objectName.methodName (parameters). The line of code userInputScanner.nextLine () calls the Scanner object using the name assigned to it, and then we call the nextLine () method, which cannot be given parameters.
   • Take note that we are storing the next line in another object - String. It is denoted in the code userInputName
6. Print a greeting for the user. After we have saved his name, we can print a greeting for that user. Remember the line System.out.println ("Hello World."); which we used in the main file with the class extension? All the code we write should go above this line. Now we can change this line to display the following text:

   System.out.println ("Hello" + userInputName + "!");

   • You must enter "hello", a username and an exclamation mark using the "Hello" + userInputName + "!" ... This is called string concatenation.
   • We have three lines: hello, ", userInputName, and"! ". The lines in Java are immutable and not editable. So by combining them, we created a new line that contains the greeting.
   • Then we use this new line as a parameter for System.out.println.

Java is a technology for the full functioning of applications and software components. Modern developers rarely do without Java when creating games. It is for this reason that users are encouraged to install and receive regular updates to the Java Runtime Environment (JRE).

The Java programming language allows you to write software for working in browsers, develop various server applications for online forums, online stores, online surveys.

With Java, you can process HTML forms and create customized services and services by combining different modules.

In addition, if Java is not installed on your computer (for example, you did not have time to download it for free), then a number of applications, games and websites on your PC simply will not start, since it is this software that ensures their speed and reliability.

JAVA features:

• automatic memory management
• creating multi-threaded applications
• database access, generic support
• detailed exception handling
• simultaneous execution of several programs
• wide range of I / O filtering tools
• classes for making HTTP requests and handling responses
• simple tools for building network applications
• standard collections: array, list, stack, etc.

Software components written in Java are translated into bytecode, which in turn is executed by the so-called Java virtual machine - a program that acts as an interpreter. The advantage of this algorithm is that it is independent of the operating system and hardware. Therefore, the same java application can run equally well on different devices.

And although it is widely believed among programmers that Java software is slower and takes up more memory than, say, created using the C language, when it comes to web development, a number of advantages put the software in question in the leader's place. This language is used not only on billions of PCs, but also on smartphones, various communicators and even televisions. Java is especially popular among online game developers. And the gamers themselves will not be able to access all the settings, for example, if they do not download Java for Minecraft.

It is important that you always have the latest version of Java installed - you can download it for free for Windows 7, 8, 10, Vista, XP from this page or on the official website. Thus, you will take care of the efficient and safe operation of Java applications.

You can also download Java for 64-bit browsers with Windows 64 bit operating system.

Java is an object-oriented programming language and an application programming platform created on its basis. Java is the environment for launching websites, e-commerce sites, forums, remote banking, virtual navigation maps, tutorials, online questionnaires and games, and other specialized web applications. Often it is simply impossible to do without this software platform, but there is always an opportunity to download Java for free on a computer with Windows 10, 8.1, 8, 7, Vista, etc. compiled for each processor architecture and operating system. Permanent link: site / ru / platform / java

A Brief History of Java Technology Development and Current Status

Java was developed by Sun Microsystems in 1991-1995, and later the technology was acquired by Oracle. The release of the new version of Java was developed through the interaction of Oracle programmers with representatives of the World-Java ecosystem, Open JDK and JavaCommunityProcess. Today you can download Java 64-bit or 32-bit for free for Windows 10, 8, 8.1 (desktop), 7 SP1, Vista SP2, Server 2008 R2 SP1 64-bit, Server 2012 and 2012 R2 64-bit to work with Internet Explorer 9 and older browsers, and Mozilla Firefox. The Java software package consists of four software components: the JRE, which is responsible for executing applets, the Java virtual machine that interprets the bytecode, base classes, and auxiliary libraries. Today Java Runtime Environment can deploy server-side Java applications, establish a connection between the browser and the Java platform. You should also pay attention to free programs with similar functionality: Microsoft .NET Framework, Microsoft Silverlight plugin, Adobe Flash Player, Adobe Shockwave Player in the Platforms and Environments section.

Java versus popular programming languages

The main advantage of Java is platform independence. The developers promise speed, durability, security and recommend the latest Java version to download for free without registration from the official site. However, according to reviews and comments of IT specialists, Java applications take up more memory, have lower performance and responsiveness, as opposed to their counterparts in C or C ++. But Java has a number of security and reliability advantages over languages ​​such as C, C ++, Python, Fortran, Ruby, PHP, JavaScript and others.

Benefits of Java Platform Independent Implementation

The developers claim that any Java applet runs perfectly on various devices running various operating systems. It is possible to download Java for free on almost any smart device and install it successfully, regardless of which operating system this device is running. This option is called not just a cross-platform, but a platform-independent implementation. The advantage of this way of working programs is the complete independence of the program code from the OS and hardware. This feature allows Java applets to run on any virtual machine compatible device.

The advantages of Java include:

Reliable and secure apps and games,
- work in multi-threaded mode,
- ideal functionality for network computing,
- powerful tools for launching network programs,
- reliable protection and encryption of information,
- direct access to web services,
- work with Java applets on the Internet,
- productive interaction with OpenGL and DirectX through Swing,
- GifWriter for working with animated gif-files,
- full support for Unicode.

Java security organization and updates

Java's impenetrable security system is due to the fact that the execution of the application is completely controlled by the JVM. Excessive authority, such as unauthorized use of data or sending information, is immediately terminated. The JRE is highly secured by maintaining a blacklist of certificates and JAR files. By default, only digitally signed verified applications can be launched. Users of previous versions are advised to remove all outdated software, download Java for free for Windows 7, 8, 8.1, 10, as well as outdated Vista and server Windows 2008 and 2012, and install the latest version on the computer. Legacy Java can have vulnerabilities, which is unsafe. To maintain a high level of security, updates should be installed regularly. Minor changes do not change indexing, but use the word Update (letter u), but they are no less important. Not surprisingly, if you need the latest Java download for Minecraft, Prince of Persia, Solitaire, Need for Speed, GTA, Zona programs, TequilaCat Book Reader, E-666 food supplement database, remote banking or other latest software. Moreover, free download Java for Minecraft and other Java games is simply necessary for high-quality video, the ability to access all the settings and normal network gameplay.

How to properly install Java on your computer

To properly install Java on your PC, you first need to uninstall everything. To remove outdated software, you should use the standard feature: Start - Control Panel - Uninstall a program. Next, you need to download Java for Windows for free from programmywindows.com, a 32- or 64-bit installation file, respectively, observing the bitness of the main browser, close all browsers and running programs. When everything is ready, you can start the installation, and when the installation is complete, you can restart your computer. If both 32-bit and 64-bit browsers are used on the computer, then both versions of Java (32-bit and 64-bit) must be installed, for compatibility of Java modules with all browsers.

Java is an object-oriented programming language designed specifically for continuous development. Java differs from other programming paradigms in functionality and logic programming because developers can continue developing a program without starting from scratch. Objects keep your code neat and organized, and easily change when needed.

For example, a car dealership has several cars. Each of the cars is an item, but each has different characteristics, called classes, which are different for different models: engine, paint colors, and so on. The customer chooses a red pickup but wants to add a stereo system. The new pickup inherits all the characteristics from the pickup object, and the programmer just needs to change the "STEREO" class, as opposed to building a completely new car. This is what makes Java the ideal platform for cell phones, forum sites, game consoles, and anything else that requires constant updating and modification. Programs written in Java are portable because they are assembled in bytecode. It can be executed on any server with Java Virtual Machine (JVM) installed. Unlike C ++, objects created in Java do not need external data references. This means the Java application will continue to run even if your operating system or some other programs crashed.

Don't confuse Java with JavaScript. The latter is an interpreted language like Microsoft's Visual Basic. It is mainly used for short programs like the ones that cause pop-ups in the web browser. JavaScript does not have Java portability, and is often used as part of HTML code. Java is the second most used programming language in the world, just behind C, and ahead of C ++ and Objective C. Plus, it is free to download and update. Java requires Windows XP or higher, Mac OS X 10.7.3 or higher, and works with a wide variety of Linux-based systems.

Do you need Java on your computer?

Sun Microsystems created Java in 1995 as a universal platform that can run an application on any machine, regardless of operating system. Java is currently installed on 3 billion devices worldwide. To run Java, you need to download and install the Java Runtime Environment (JRE) on your computer. The JRE contains the Java Virtual Machine (JVM) and all the classes for creating items. Java is especially useful for programmers, but it is also essential for end users working with applications from a Java applet. Russian antivirus company Kaspersky Lab, said that half of all cyber attacks in 2012 were directly caused by Java. Most major websites, including Facebook and Twitter, use HTML 5 instead of Java to avoid security threats. Java was once considered the future of the Internet and was absolutely essential to run almost everything. Now, most cybersecurity experts recommend that you regularly check for Java updates if you have one on your computer.

Is Java free?

Sun Microsystems made most of the core code in Java available to the public as free and open source software back in 2007, under the terms of the GNU General Public License. Today, Oracle claims that Java Development Kit (JDK) is free to download. Oracle has accused Google of copyright infringement by using Java code in the Android operating system without paying a license fee. Google claims that the code used is in the public domain, so the company is not required to pay licensing fees. Google eventually cleared most of the claims, but the case is currently being appealed. The simple answer to this question for ordinary computer users is "Java is free"! Programmers and companies using it for commercial purposes are required to pay licensing fees.

Where can I download Java?

Java Runtime Environment(JRE, for general users) can be downloaded from our website. Our site is one of the most trusted sites and receives positive feedback from users. Don't trust any other website that claims to offer free Java downloads as you run the risk of getting a bunch of malware and trojans.

Why update Java?

Java and all subsequent versions of the application will notify users of the availability of updates, as there are security risks. It is recommended to install updates and patches necessary for the full work of Java. Beware of false updates such as "Java Update 11" for Windows. The file will look like "javaupdate11.jar." Once installed, it creates a "backdoor" for hackers to harm your system. Keeping Java up to date is important for security and performance. Java Auto Update automatically checks for required updates and fixes. You can install it to search for updates, or check for updates manually at any time. Oracle recommends leaving enabled Java Auto Update... Which, by default, will notify users once a month when the necessary updates are available.