As a senior programmer, Ding to answer this question.Java in general is considered a back-end development program language. So can Java be used for front-end? Of course it can. There are so many ways to do front-end with Java.

One is mobile programming, such as Android mobile application development, you can use Java to write programs.

Another way is to use Google webtoolkit, a toolkit that converts Java code into JavaScript, which can be used by the front-end. A well-known example is primeng. This front-end control library can be used both in the desktop front-end written in Java, and can be used in the front-end of the web development. Its code implementation is partly in Java.

Another type is the regular Java desktop application of the past. You can directly use the java interface development kit for application development. With the development of web applications, desktop applications have become less popular than before.

Another must mention is that now very famous software development tools such as eclipse, netbeans, intellij are developed in Java.

The above said, Java front-end development part. Here to say, Java back-end development applications.

One is the Java web application development. This type of technology springboot, springmvc, struts, or similar e-commerce architecture are developed using the Java language.

Another is the field of big data technology, Hadoop, kafaka and other big data technology are using Java.

Another is the field of scientific applications. This field includes natural language processing, artificial intelligence analysis, machine language research and so on. Java is the default option if a programming language is used in this area. This is because Java is safer, more portable, more maintainable, and has high-quality concurrency tools.

The last one should be considered the embedded field. In fact, the original positioning of Java was embedded systems development. It only needed 13 megabytes of memory to run. A lot of devices, like ah, SIM cards ah, photolithography players, some meters, TVs, are using embedded Java technology.

The above speaks broadly about the specific application areas of Java as a programming language, and I'd love to hear your thoughts