Conclusion  : Unlike User-Agent ,which let the browser describe its meta data and information , the two kinds of client by default will not have a pre-defined field which can function like this.

Solution: (We created a self-defined field in the http header)

For example ,we create a field named Mobile-Agent

In client side:

when we construct the http request ,we add the value of header “Mobile-Agent” to be some value

Android Client code only need to  set the “Mobile-Agent” header to be ” Android”.

Code example:  (see my highlighted)

1. public JSONObject callJSONWebService(String url) { 
2.  
3.             HttpParams my_httpParams = new BasicHttpParams(); 
4.  
5.             HttpConnectionParams.setConnectionTimeout(my_httpParams, conn_timeout); 
6.  
7.             HttpConnectionParams.setSoTimeout(my_httpParams, conn_timeout); 
8.  
9.             
10.  
11.             HttpClient httpClient = new DefaultHttpClient(my_httpParams); 
12.  
13.             HttpGet httpRequest = new HttpGet(url); 
14.  
15.   
16.  
17.             httpRequest.setHeader("User-Agent","bleum agent"); 
18.  
19.             httpRequest.setHeader(“Mobile-Agent”,”Android”); 
20.  
21.             HttpResponse httpResponse = null; 
22.  
23.             
24.  
25.             JSONObject httpJsonResult = null; 
26.  
27.             String result = null; 
28.  
29.             try { 
30.  
31.                   httpResponse = httpClient.execute(httpRequest); 
32.  
33.                   if(httpResponse.getStatusLine().getStatusCode() == 200){ 
34.  
35.                         HttpEntity httpEntity = httpResponse.getEntity(); 
36.  
37.                         if(httpEntity != null){ 
38.  
39.                               InputStream inputStream = httpEntity.getContent(); 
40.  
41.                               result = this.convertStreamToString(inputStream); 
42.  
43.                               httpJsonResult = new JSONObject(result); 
44.  
45.                               inputStream.close(); 
46.  
47.                         } 
48.  
49.                   } 
50.  
51.             } catch (Exception e) { 
52.  
53.                   System.out.println("call JsonWebService failed."); 
54.  
55.                   e.printStackTrace(); 
56.  
57.             } 
58.  
59.             httpClient.getConnectionManager().shutdown(); 
60.  
61.             return httpJsonResult; 
62.  
63.       } 
64.  
65.   

IPhone Client code can use Objective-C to do the similar thing ,just set the “Mobile-Agent” header to be “IPhone”

In server side’s servlet :

we only use the Servlet API to resolve “Mobile-Agent” field.

Then solved.