JAVA无处不在。你可以不会这个，不会那个，不可以不会JAVA。
网页现在都是用的JavaScript。这东西听起来象是JAVA亲戚一样，实际上完全不同。现在wasm流行，可以把Java转换为wasm。具体来说
TeaVM - an ahead-of-time translating compiler (transpiler) of Java bytecode, that's capable of emitting JavaScript and WebAssembly.
https://github.com/konsoletyper/teavm
JWebAssembly - A Java bytecode to WebAssembly compiler. It can generate the WebAssembly binary or text format. It is written in Java itself and can be integrated with other Java build tools.
Bytecoder - A Rich Domain Model for Java Bytecode and Framework to interpret and transpile it to other languages such as JavaScript, OpenCL or WebAssembly.
https://github.com/mirkosertic/Bytecoder
CheerpJ - A Java compiler for the web that converts any Java client application into standard HTML5/WebAssembly/JavaScript.
参考：
https://github.com/appcypher/awesome-wasm-langs#java
https://stackoverflow.com/questions/43540878/what-languages-can-be-compiled-to-webassembly-wasm
