将数据从 servlet 发送到小程序:我该如何实现? [英] Sending data from a servlet to applet : How can I implement this?

问题描述

我想将发送 HashMap 对象发送到请求它的小程序.servlet 具有该 HashMap 对象.有没有办法做到这一点?

I want to send send HashMap object to the applet that requested it. A servlet has that HashMap object. Is there a way I can do this ?

Applet ------requests HashMap object---->Servlet listens to this request
                                                 |
                                                 |
                                     Servlet searches that HashMap Object
                                                 |
                                                 |
                                                \ /
<--Finally Send this to applet------------ Servlet gets the HashMap object                                                                

我已经建立了到 servlet 的连接，我的 servlet 也有 HashMap 对象，但我不知道如何将它发送到小程序，我想知道它是否可以发送！

I have made a connection to the servlet and my servlet also has the HashMap object,but I don't know how to send it to the applet and I wonder if it can be sent !

推荐答案

我将利用一些外部库来回答您的问题:Google Gson 和 Apache IO 实用程序.

I'm going to make use of some external libraries in order to answer your question: Google Gson and Apache IO Utils.

因此您的 Servlet 中已经有了 HashMap 并希望将其发送到 Applet:

So you already have the HashMap in your Servlet and want to send it to the Applet:

Map<String, String> myMap = new HashMap<String, String>();// or whatever
Gson gson = new GsonBuilder().create();
String jsonString = gson.toJson(myMap);
IOUtils.write(jsonString, resp.getOutputStream());// where 'resp' is your HttpServletResponse
IOUtils.closeQuietly(resp.getOutputStream());

并在您的小程序中接收它:

And to receive it in your Applet:

String jsonString = IOUtils.toString(conn.getInputStream()); // where 'conn' is an HttpURLConnection
IOUtils.closeQuietly(connection.getInputStream());
Gson gson = new GsonBuilder().create();
// The TypeToken is needed when Generics are involved
Type typeOfHashMap = new TypeToken<Map<String, String>>() {}.getType();
Map<String, String> myMap = gson.fromJson(jsonString, typeOfHashMap);

就是这样.这只是一个简单的例子，但我希望你能从中有所收获.

And that's it. It's just a simple example but I hope you get something out of it.

当然，您可以手动完成，而不是使用外部库，但这种方式要容易得多.

Of course you could be doing it by hand instead of using external libraries, but this way is much easier.

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