Where is Java used and why is it needed?

If you are a beginner and just starting to learn Java, you have probably wondered where exactly is Java used? You don't see many games written in Java, except for Minecraft, desktop utilities like Adobe Acrobat, Microsoft Office are not written in Java, neither is your operating system, be it Linux or Windows, so where is use Java? Does it have any real use at all? Well, you are not alone, many programmers who have just embarked on the IT path or are already confident specialists ask this question. Meanwhile, you can find out where Java is used by simply installing Java on your computer, Oracle claims that over 3 billion devices run Java, quite a large number, right? Most large companies use Java in one way or another. Many back-end applications processing tens of millions of requests per day are written in Java, and high-frequency trading applications are also written in Java, such as LMAX's trading applications using their innovative multi-threaded parallel Disruptor framework . In this article, we'll take a closer look at what projects use Java, what areas does it dominate, and where is it even applicable in the real world?

Real Java Applications

There are many applications for Java, from e-commerce sites to Android applications, from scientific to financial applications such as trading systems, from games such as Minecraft to desktop software such as Eclipse, Netbeans and IntelliJ, from open source frameworks to J2ME applications, etc. Let's take a closer look at each of them.

Android applications

If you want to see where Java is used, you don't have to look far. Just take your Android phone, absolutely all applications are written in Java, using Google and Android APIs, which are similar to the JDK. A couple of years ago, Android provided the necessary capabilities, thanks to which today many Java programmers are Android developers. By the way, Android uses a different JVM and a different and different layout method, but the code is still written in Java.

Server Applications in Financial Services

Java is widely used in the financial sector. Many global investment banks, such as Goldman Sachs, Citigroup, Barclays, Standard Charted and others use Java to write front-end and back-end office electronic systems, regulatory and confirmation systems, data processing projects and some others. Java is primarily used to write server applications, most of them without any user interface, that receive data from one server, process it and send it on. Java Swing was also popular for creating thick-client interfaces, but now C# is quickly taking over the market in this area, and Swing is already running out of steam.

Web applications

Java is also widely used in e-commerce and web applications. A huge number of RESTful services have been created using Spring MVC, Struts 2.0 and similar frameworks. Even simple applications based on Servlet, JSP and Struts are quite popular in various government projects. Many web applications of government, health, insurance, education, defense and some other departments are written in Java.

Software

Many useful software and development tools are written and developed in Java, such as Eclipse, IntelliJ Idea and Netbeans IDE. It seems to me that this is also the most used application written in Java. There was a time when Swing was very popular for creating "fat clients", mainly in the financial sector. Today, Java FX is gaining more and more popularity, but it is still not a replacement for Swing, and C# has almost completely displaced Swing from the financial field.

Trading Applications

Third-party trading applications, which are also part of the larger financial services industry, also use Java. Popular applications such as Murex, which are used in many banks, are written in Java.

J2ME applications

Despite the fact that the emergence of iOS and Android has practically destroyed the J2ME market, there are still a huge number of cheap phones from Nokia and Samsung using J2ME in the world. There was a time when almost all games and applications available on Android were written using MIDP and CLDC, which are part of the J2ME platform. J2ME is still popular in media such as Blu-ray, cards and set-top boxes. One of the reasons WhatsApp is so popular is that it is also available on J2ME.

Embedded Systems

Java is also extensive in the field of embedded systems. You can see what the platform is capable of, you only need 130 KB to use Java (on smart cards and sensors). Java was originally developed for embedded systems. In fact, this area was part of Java's initial "write once, run anywhere" campaign, and it appears to be paying off.

Big Data

Hadoop and other big data technologies use Java in one way or another, such as Hbase and Accumulo from Apache, or ElasticSearch. Although Java does not dominate this area, since there are technologies like MongoDB, which are written in C++. Java has the potential to gain a larger share of this growing space if Hadoop or ElasticSearch expands.

High Frequency Trading Spaces

Java has improved its performance and with modern JITs it is able to provide C++ level performance. For this reason, Java is also popular for writing high-performance systems, because although the performance is inferior in comparison with the native language, you can sacrifice security, portability and reliability for greater speed and it only takes one inexperienced C++ programmer to make the application slow and unreliable .

Scientific applications

These days, Java is often the default choice for scientific applications, including natural language processing. The main reason is that Java is more secure, mobile and reliable and has better parallelization tools than C++ and other languages. In the nineties, Java was quite popular on the Internet thanks to applets, but over the years, applets have lost their popularity, mainly due to various security issues. Desktop Java and applets are pretty much dead these days. Java is the default darling of the software industry, and is widely used in finance, investment banking, and e-commerce. Everyone who learns Java has a bright future. Java 8 has only strengthened the belief that Java will continue to dominate the development landscape for years to come. In the comments to the article, they questioned the real use of Java, due to the abundance of financial examples in the article itself, and wondered whether Java has a future in desktop development, and whether it would be better to learn C#? Here are some counterarguments: There is no point for a Java developer to learn C# as they are similar language but just for different technical stack, instead you should learn Python, Ruby or Perl. Scripting language are very good for small tasks. There is no point for a Java developer to learn C# since they are similar languages ​​but for different areas. Instead, it's better to learn Python, Ruby or Perl. Scripting languages ​​are good for small tasks. Java is actually used EVERYWHERE, it's in your phone, it's in your cable's settop box, it's in your credit card, it's on the server which you are currently connected to, it's on the browser you are currently using it. Java is the most ubiquitous language ever created. Java is actually used everywhere, it's on your phone, on your set-top box, on your credit card, on the server you're currently connected to, in the browser you're currently using. Java is the most ubiquitous language ever created. Also in the comments are links to a couple of articles, namely: The Second Coming of Java and Employers Want Java Knowledge Like Nothing Else . If they express their desires, we can translate them too. PS: I ask you to evaluate the translation, make comments, point out errors, because I have a desire to translate and want everything to be at the appropriate level. Translation and revision of the article Where is Java used in Real World?