如何在Android中使用簡單HTTP客戶端？

Question

如何使用AndroidHttpClient作爲HTTP客戶端連接到遠程服務器？我無法在文檔或互聯網上找到好的例子。

Answer 1

public static void connect(String url) 
{ 

    HttpClient httpclient = new DefaultHttpClient(); 

    // Prepare a request object 
    HttpGet httpget = new HttpGet(url); 

    // Execute the request 
    HttpResponse response; 
    try { 
     response = httpclient.execute(httpget); 
     // Examine the response status 
     Log.i("Praeda",response.getStatusLine().toString()); 

     // Get hold of the response entity 
     HttpEntity entity = response.getEntity(); 
     // If the response does not enclose an entity, there is no need 
     // to worry about connection release 

     if (entity != null) { 

      // A Simple JSON Response Read 
      InputStream instream = entity.getContent(); 
      String result= convertStreamToString(instream); 
      // now you have the string representation of the HTML request 
      instream.close(); 
     } 


    } catch (Exception e) {} 
} 

    private static String convertStreamToString(InputStream is) { 
    /* 
    * To convert the InputStream to String we use the BufferedReader.readLine() 
    * method. We iterate until the BufferedReader return null which means 
    * there's no more data to read. Each line will appended to a StringBuilder 
    * and returned as String. 
    */ 
    BufferedReader reader = new BufferedReader(new InputStreamReader(is)); 
    StringBuilder sb = new StringBuilder(); 

    String line = null; 
    try { 
     while ((line = reader.readLine()) != null) { 
      sb.append(line + "\n"); 
     } 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } finally { 
     try { 
      is.close(); 
     } catch (IOException e) { 
      e.printStackTrace(); 
     } 
    } 
    return sb.toString(); 
} 

Answer 2

你可以使用這樣的：

public static String executeHttpPost1(String url, 
      HashMap<String, String> postParameters) throws UnsupportedEncodingException { 
     // TODO Auto-generated method stub 

     HttpClient client = getNewHttpClient(); 

     try{ 
     request = new HttpPost(url); 

     } 
     catch(Exception e){ 
      e.printStackTrace(); 
     } 


     if(postParameters!=null && postParameters.isEmpty()==false){ 

      List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(postParameters.size()); 
      String k, v; 
      Iterator<String> itKeys = postParameters.keySet().iterator(); 
      while (itKeys.hasNext()) 
      { 
       k = itKeys.next(); 
       v = postParameters.get(k); 
       nameValuePairs.add(new BasicNameValuePair(k, v)); 
      }  

      UrlEncodedFormEntity urlEntity = new UrlEncodedFormEntity(nameValuePairs); 
      request.setEntity(urlEntity); 

     } 
     try { 


      Response = client.execute(request,localContext); 
      HttpEntity entity = Response.getEntity(); 
      int statusCode = Response.getStatusLine().getStatusCode(); 
      Log.i(TAG, ""+statusCode); 


      Log.i(TAG, "------------------------------------------------"); 





       try{ 
        InputStream in = (InputStream) entity.getContent(); 
        //Header contentEncoding = Response.getFirstHeader("Content-Encoding"); 
        /*if (contentEncoding != null && contentEncoding.getValue().equalsIgnoreCase("gzip")) { 
         in = new GZIPInputStream(in); 
        }*/ 
        BufferedReader reader = new BufferedReader(new InputStreamReader(in)); 
        StringBuilder str = new StringBuilder(); 
        String line = null; 
        while((line = reader.readLine()) != null){ 
         str.append(line + "\n"); 
        } 
        in.close(); 
        response = str.toString(); 
        Log.i(TAG, "response"+response); 
       } 
       catch(IllegalStateException exc){ 

        exc.printStackTrace(); 
       } 


     } catch(Exception e){ 

      Log.e("log_tag", "Error in http connection "+response);   

     } 
     finally { 

     } 

     return response; 
    } 

Answer 3

您可以使用此代碼：

int count; 
      try { 
       URL url = new URL(f_url[0]); 
       URLConnection conection = url.openConnection(); 
       conection.setConnectTimeout(TIME_OUT); 
       conection.connect(); 
       // Getting file length 
       int lenghtOfFile = conection.getContentLength(); 
       // Create a Input stream to read file - with 8k buffer 
       InputStream input = new BufferedInputStream(url.openStream(), 
         8192); 
       // Output stream to write file 
       OutputStream output = new FileOutputStream(
         "/sdcard/9androidnet.jpg"); 

       byte data[] = new byte[1024]; 
       long total = 0; 
       while ((count = input.read(data)) != -1) { 
        total += count; 
        // publishing the progress.... 
        // After this onProgressUpdate will be called 
        publishProgress("" + (int) ((total * 100)/lenghtOfFile)); 
        // writing data to file 
        output.write(data, 0, count); 
       } 
       // flushing output 
       output.flush(); 
       // closing streams 
       output.close(); 
       input.close(); 
      } catch (SocketTimeoutException e) { 
       connectionTimeout=true; 
      } catch (Exception e) { 
       Log.e("Error: ", e.getMessage()); 
      }