java 公式字符串替換計算

static ScriptEngine JavaScriptMath = new ScriptEngineManager().getEngineByName("JavaScript");

public static void main(String[]args){
        try {
            String s = "Math.sqrt(#a#+#b#)";
            s=s.replaceAll("#a#","100");
            s=s.replaceAll("#b#","100");
            System.out.println(s);
            System.out.println(JavaScriptMath.eval(s));
        } catch (ScriptException e) {
            e.printStackTrace();
        }
}