Android http请求例子、Unicode转UTF-8 java代码收藏

http://blog.csdn.net/wyzxk888/article/details/7337649

Android项目经常是C/S模型的，因此需要向服务器发出http请求，收藏一个http请求的例子以便以后可以用。

假设发出的请求使用get方法，服务器传回JSON数据，解析代码如下：

[java] view plaincopyprint?

1. HttpClient client = new DefaultHttpClient(); 
2. HttpGet httpGet = new HttpGet(req_url); 
3. try { 
4.     HttpResponse response = client.execute(httpGet); 
5.     int statusCode = response.getStatusLine().getStatusCode(); 
6.     if (statusCode != HttpStatus.SC_OK) { 
7.         Log.d("AD", "statusCode is " + statusCode); 
8.         return null; 
9.     }  
10.     else { 
11.         HttpEntity entity = response.getEntity(); 
12.         if (entity != null) { 
13.             InputStream inputStream = entity.getContent(); 
14.             StringBuilder builder = new StringBuilder(); 
15.             BufferedReader bufferedReader  = new BufferedReader(new InputStreamReader(inputStream)); 
16.             for (String s = bufferedReader.readLine(); s !=null; s = bufferedReader.readLine()) { 
17.                 builder.append(s); 
18.             } 
19.             String result = builder.toString(); 
20.                      
21.             Log.d("AD", "Server return " + result); 
22.             return result; 
23.                      
24.         } 
25.     }  
26. } catch (Exception e) { 
27.     httpGet.abort(); 
28.     Log.d("AD", "when http get, exception is " + e.getMessage()); 
29. } 
30. return null; 

HttpClient client = new DefaultHttpClient();HttpGet httpGet = new HttpGet(req_url);try {HttpResponse response = client.execute(httpGet);int statusCode = response.getStatusLine().getStatusCode();if (statusCode != HttpStatus.SC_OK) {Log.d("AD", "statusCode is " + statusCode);return null;} else {HttpEntity entity = response.getEntity();if (entity != null) {InputStream inputStream = entity.getContent();StringBuilder builder = new StringBuilder();BufferedReader bufferedReader  = new BufferedReader(new InputStreamReader(inputStream));for (String s = bufferedReader.readLine(); s != null; s = bufferedReader.readLine()) {builder.append(s);}String result = builder.toString();Log.d("AD", "Server return " + result);return result;}} } catch (Exception e) {httpGet.abort();Log.d("AD", "when http get, exception is " + e.getMessage());}return null;

注：JSON数据格式其实就是String。可以用JSONObject类进行转化。

有时候服务器传回的数据中会遇到传回数据为Unicode的情况，为此需要进行Unicode转UTF-8的转化，我在项目中遇见过，为此收藏一份转化 java 代码，便于以后使用：

[java] view plaincopyprint?

1. private static String decodeUnicode(String theString) { 
2.     char aChar; 
3.     int len = theString.length(); 
4.     StringBuffer outBuffer = new StringBuffer(len); 
5.     for (int x =0; x < len;) { 
6.         aChar = theString.charAt(x++); 
7.         if (aChar == '\\') { 
8.             aChar = theString.charAt(x++); 
9.             if (aChar =='u') { 
10.                 // Read the xxxx 
11.                 int value =0; 
12.                 for (int i =0; i < 4; i++) { 
13.                     aChar = theString.charAt(x++); 
14.                     switch (aChar) { 
15.                     case'0': 
16.                     case '1': 
17.                     case'2': 
18.                     case '3': 
19.                     case'4': 
20.                     case '5': 
21.                     case'6': 
22.                     case '7': 
23.                     case'8': 
24.                     case '9': 
25.                         value = (value << 4) + aChar - '0'; 
26.                         break; 
27.                     case'a': 
28.                     case 'b': 
29.                     case'c': 
30.                     case 'd': 
31.                     case'e': 
32.                     case 'f': 
33.                         value = (value << 4) + 10 + aChar - 'a'; 
34.                         break; 
35.                     case'A': 
36.                     case 'B': 
37.                     case'C': 
38.                     case 'D': 
39.                     case'E': 
40.                     case 'F': 
41.                         value = (value << 4) + 10 + aChar - 'A'; 
42.                         break; 
43.                     default: 
44.                         throw new IllegalArgumentException( 
45.                                 "Malformed   \\uxxxx   encoding."); 
46.                     } 
47.  
48.                 } 
49.                 outBuffer.append((char) value); 
50.             } else { 
51.                 if (aChar =='t') 
52.                     aChar = '\t'; 
53.                 else if (aChar == 'r') 
54.                     aChar = '\r'; 
55.                 else if (aChar == 'n') 
56.                     aChar = '\n'; 
57.                 else if (aChar == 'f') 
58.                     aChar = '\f'; 
59.                 outBuffer.append(aChar); 
60.             } 
61.         } else 
62.             outBuffer.append(aChar); 
63.     } 
64.     return outBuffer.toString(); 
65. }