java 腳本引擎執行javascript腳本

java腳本引擎是從JDK6.0之后添加的新功能，語法使用Rhino。

public class ScriptTest {
    public static void main(String args[]) throws ScriptException, NoSuchMethodException, IOException {
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("javascript");

        //聲明一個msg 變量
        engine.put("msg","this is msg!");

        String jsCode = "var a = 10; var b =20;println(a+b);";
        //執行javascript代碼
        engine.eval(jsCode);
        //修改變量
        engine.eval("msg = 'this is msg2!';println(msg);");
        //使用java獲取變量
        System.err.println(engine.get("msg"));
        //執行js方法
        String jsFunc="function add(a,b){return a+b}";
        engine.eval(jsFunc);
        Invocable invocable = (Invocable) engine;
        Object res = invocable.invokeFunction("add",new Object[]{5,7});
        System.err.println(res);

        //在腳本中使用java
        String importJava = "importPackage(java.util);var list = Arrays.asList([\"嘻嘻\",\"哈哈\",\"咕咕\"]);";
        engine.eval(importJava);
        List list = (List) engine.get("list");
        System.err.println(list);

        //執行js文件
        URL url = ScriptTest.class.getClassLoader().getResource("test.js");
        FileReader reader = new FileReader(url.getPath());
        engine.eval(reader);
        reader.close();

    }

test.js(src下)

var a = 10;
var b = 30;
function mul() {
    return a*b;
}

println(mul());