易变业务用脚本编写

public class Test {
    public static void main(String[] args) throws FileNotFoundException, ScriptException, NoSuchMethodException{
        
        
        //获取javascript的执行引擎
        ScriptEngine  engine= new ScriptEngineManager().getEngineByName("javascript");
        //建立上下文变量
        Bindings bind=engine.createBindings();
        bind.put("factor", 1);
        //绑定上下文，作用域是当前引擎范围
        engine.setBindings(bind, ScriptContext.ENGINE_SCOPE);
        Scanner input=new Scanner(System.in);
        while(input.hasNextInt())
        { 
            int first=input.nextInt();
            int sec=input.nextInt();
            System.out.println("输入参数是："+first+","+sec);
            //执行js代码 
            engine.eval(new FileReader("c:/model.js")); 
            //是否可调用方法 
            if(engine instanceof Invocable){
                Invocable in=(Invocable)engine; 
                //执行js中的函数 
                Double result=(Double)in.invokeFunction("formula",first, sec);
                System.out.println("运算结果："+result.intValue());

            }

        }

        
    }

js文件代码

function formula(var1,var2){
return var1+var2+2;
}