1, Android application If you want to know where the Java application is, you are not far from the answer. Open your Android phone or any application, which is completely Google AndroidAPI written in Java programming language, which is very similar to JDK. A few years ago, Android just started. Today, many Java programmers are developers of Android App.
2. The server application Java in the financial services industry has a great application in the financial services industry. Many global investment banks, such as GoldmanSachs (Goldman Sachs), Citigroup (Citigroup), Barclays (Barclays Bank), Standard Chartered Bank and others, use Java to write front-end and back-end electronic trading systems, settlement, information confirmation systems, data processing projects and other projects.
Java is used to write server applications, but most of them have no front end. They all receive data from one server (upper layer), process the data and send it to other processing systems (lower layer). JavaSwing is very popular because it can develop clients with graphical user interface for traders to use, but now C# is rapidly replacing the Swing market, which brings pressure to Swing.
3. Website application Java is also widely used in e-commerce and website development. You can use many RESTfull architectures, which are developed with SpringMVC, Struts2.0 and similar frameworks. Even simple Servlet, JSPs and Struts are very popular in various government projects. Many websites of government, medical care, insurance, education, national defense and other departments are built on Java.
4. Software Tools Many useful software and development tools are written and developed in Java, such as Ecilpse, InetelliJIdea and NetbansIDE. I think these are common desktop applications written in Java.
As mentioned above, Swing used to be very popular in the client development of graphical user interfaces, mostly used in financial services and investment banks. Although JavaFx is becoming more and more popular now, it still cannot replace Swing, and C# has replaced Swing in most financial fields.
5. Trading system The third-party trading system is a major part of the financial services industry and is also written in Java. For example, popular trading systems such as Murex, which are used for front-end links with many banks, are also written in Java.
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6. Although the emergence of IOS and Android almost killed the J2ME market, there are still many low-end Nokia and Samsung mobile phones using J2ME. At one time, most games and mobile phone applications were written using MIDP and CLDC or some J2ME platforms, so as to be suitable for Android system. J2ME is still very popular in Blu-ray, magnetic cards, set-top boxes and other products. App is so popular because it still applies to all Nokia phones in J2ME.
7. Embedded domain Java is also widely used in embedded domain. You only need 130KB to use Java technology (on a small chip or sensor), which shows how reliable this platform is. Java was originally designed for embedded devices. In fact, this is also part of Java's original theme "Write it now and run it everywhere".
8. Hadoop and other big data technologies also use Java to varying degrees, such as Apache's Java-based Hbase, Accumulo (open source) and ElasticSearch. But Java does not occupy the whole field, and other big data technologies such as MongoDB are written in C++. If Hadoopor ElasticSearch develops gradually, Java will have the potential to gain more development space in the field of big data technology.
9. In the field of high-frequency trading, Java platform has greatly improved its performance characteristics and JITS, and Java also has the same transmission performance as C++. Therefore, Java is also very popular in writing high concurrency systems. Although the transmission performance of Java is not as good as that of C++, you don't have to consider the security, portability and maintainability of Java (which has been implemented internally), and Java runs faster. Problems such as security will make the applications written by inexperienced C++ programmers more slow and unreliable.
10, scientific applications Now Java is usually the default choice for scientific applications, including natural language processing. This is mainly because Java is more secure, portable and maintainable than C++ or other languages, and Java has better advanced concurrency tools.
In fact, no matter which field you choose, as long as your technology is strong enough, it is not a problem.