你可以很容易地建立一个。

You could build one pretty easily.

像div一样设置如下：

Have something like a div set up like this:

<div id="java-applet">
Message to user saying that they need Java here
</div>

然后添加 Java插件检测（ builder ）你的JavaScript。然后，如果返回true，则执行以下操作：

Then add Java Plugin Detection (builder) to your JavaScript. Then if that returns true, then do something like:

document.getElementById("java-applet").innerHTML = "<applet>stuff here</applet>";