从servlet到小程序发送数据：我怎样才能实现呢？ [英] Sending data from a servlet to applet : How can I implement this?

问题描述

我想送送的HashMap 对象请求它的小程序。一个servlet有的HashMap 对象。有没有一种方法可以让我做到这一点？

 小程序------要求HashMap对象----＆GT;的Servlet听这个请求
                                                 |
                                                 |
                                     Servlet的搜索是HashMap对象
                                                 |
                                                 |
                                                \\ /
＆LT;  - 最后发送给小程序------------的Servlet得到HashMap对象
 

我已经到Servlet的连接，我的servlet还具有的的HashMap 的对象，但我不知道如何将它发送到小程序，我不知道它是否可以发送<！ / p>

解决方案

我要利用一些外部库，以回答你的问题：的谷歌GSON 并的 Apache的IO utils的。

所以，你已经在你的servlet HashMap中，并希望其发送到小程序：

 地图＆LT;字符串，字符串＆GT; MYMAP =新的HashMap＆LT;字符串，字符串＆GT;（）; //或什么
GSON GSON =新GsonBuilder（）创建（）。
字符串jsonString = gson.toJson（MYMAP）;
IOUtils.write（jsonString，resp.getOutputStream（））; //其中'RESP'是你的HttpServletResponse
IOUtils.closeQuietly（resp.getOutputStream（））;
 

和接收它在你的小程序：

 字符串jsonString = IOUtils.toString（conn.getInputStream（））; //其中'参数conn是一个HttpURLConnection类
IOUtils.closeQuietly（connection.getInputStream（））;
GSON GSON =新GsonBuilder（）创建（）。
//当泛型参与是必须的TypeToken
键入typeOfHashMap =新TypeToken＆LT;地图＆LT;字符串，字符串＆GT;＆GT;（）{} .getType（）;
地图＆LT;字符串，字符串＆GT; MYMAP = gson.fromJson（jsonString，typeOfHashMap）;
 

就是这样。这只是一个简单的例子，但我希望你得到的东西出来。

当然，你可以做手工，而不是使用外部库，但这种方式要容易得多。

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                                                                

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 !

解决方案

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

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());

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);

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

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

这篇关于从servlet到小程序发送数据：我怎样才能实现呢？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！