Java利用ScriptEngineManager对计算公式的支持

public static void main(String[] args) {
        ScriptEngineManager manager = new ScriptEngineManager();
        ScriptEngine engine = manager.getEngineByName("JavaScript");
        try {
            System.out.println(engine.eval("a*2".replace("a","2")));
            System.out.println(engine.eval("a<2".replace("a","1")));
        } catch (ScriptException e) {
            e.printStackTrace();
        }

    }