rhino

Rhino is an open-source implementation of JavaScript written entirely in Java.

It is typically embedded into Java applications to provide scripting to end users.

It is embedded in J2SE 6 as the default Java scripting engine.

https://developer.mozilla.org/en-US/docs/Rhino

Invoke JavaScript from Java example

   1 // /tmp/test.js
   2 function isOdd(number) { 
   3   if(number % 2){
   4     return false;
   5   }
   6   else{
   7   return  true;  
   8   }
   9 };

   1 import javax.script.Invocable;
   2 import javax.script.ScriptEngine;
   3 import javax.script.ScriptEngineManager;
   4 import javax.script.ScriptException;
   5 import java.io.FileNotFoundException;
   6 import java.io.FileReader;
   7 
   8 public class JSTest {
   9 
  10         /**
  11          * @param args
  12          */
  13         public static void main(String[] args) {
  14                 ScriptEngineManager sem = new ScriptEngineManager();
  15                 ScriptEngine engine = sem.getEngineByName("ECMAScript");
  16                 FileReader fr = null;
  17                 String path = "/tmp/test.js";
  18                 try {
  19                         fr = new FileReader(path);
  20                 } catch (FileNotFoundException e) {
  21                         System.out.println(String.format("File %s not found", path));
  22                 }
  23 
  24                 if (fr != null) {
  25                         try {
  26                                 engine.eval(fr);
  27                                 if (engine instanceof Invocable) {
  28                                         Invocable iv = (Invocable) engine;
  29 
  30                                         try {
  31                                                 System.out.println(iv.invokeFunction("isOdd", new Integer(4)));
  32                                                 System.out.println(iv.invokeFunction("isOdd", new Integer(5)));
  33                                         } catch (NoSuchMethodException ex) {
  34                                                 ex.printStackTrace();
  35                                         } catch (ScriptException ex) {
  36                                                 ex.printStackTrace();
  37                                         }
  38                                 }
  39                         } catch (ScriptException ex) {
  40                                 ex.printStackTrace();
  41                         }
  42                 }
  43         }
  44 
  45 }