服务器 - Android应用程序和服务器之间的客户端连接

Question

我正在开发Java服务器应用程序和Android应用程序，我的Android应用程序需要从/向服务器发送和接收数据（双向），例如我的Android应用程序需要登录到服务器，服务器需要知道谁登录在.Wich协议你建议我做这种程序吗？

Answer 1

Usually in this situation you can use HTTP protocol for several reason. First of all you can reach your server even if it is behind a firewall or something like that. Second using HTTP you can send XML or JSON data widely used in android. The only limitation you have is the HTTP protocol is a synchronous protocol so you send and wait for the answer. Using HTTP you can use your existing server architecture and you can wrap your business layer with a Webservices so that you can expose your services. If you need that server can contact your app you can use you can use Google Cloud Mesaging.

Answer 2

Use Http request (get or post request) to communicate with a server. You have to use a thread or an AsyncTask to perform your request or the execution fails from Api 11+. I attach an example of http request that receives an xml:

    import org.apache.http.*;
    [..]

    public String getXmlFromUrl(String url) {
    String xml = null;

    try {
        // defaultHttpClient
        DefaultHttpClient httpClient = new DefaultHttpClient();
        HttpGet httpGet = new HttpGet(url);
        HttpResponse httpResponse = httpClient.execute(httpGet);
        HttpEntity httpEntity = httpResponse.getEntity();
        xml = EntityUtils.toString(httpEntity);
    } catch (UnsupportedEncodingException e) {
        Log.d("XMLParser-getXmlFromUrl", "UnsupportedEncodingException");
        e.printStackTrace();
    } catch (ClientProtocolException e) {
        Log.d("XMLParser-getXmlFromUrl", "ClientProtocolException");
        e.printStackTrace();
    } catch (IOException e) {
        Log.d("XMLParser-getXmlFromUrl", "IOException");
        e.printStackTrace();
    }
    // return XML
    return xml;
}