从Java源代码调用用Java编写的脚本

Question

I am aware of the Java Scripting API (which runs scripts written in JavaScript, Groovy etc) and several expression languages (SpEL, JEXL, JUL). But it is possible to write scripts in Java itself and then invoke that script from Java code?

I found some information on compiling Java programmatically via the tools API but this not like scripting (ie the context is different).

I imagine something like this script being executed by my Java code:

int i = 42 + getFoo();
setBar(i);

Now - when invoked with a context that provides getFoo and setBar methods - it should evaluate i and call the method.

Answer 1

Try BeanShell or the Compiler API or javax.script ...

one either has to interpret the text input or compile to byte-code, somehow.

Answer 2

Consider using exp4j 's nice API. Also check out other options at https://stackoverflow.com/a/41532702/37020