如何在 Android 中使用 Simple HTTP 客户端？

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();
}

你可以这样使用:

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;
}

您可以使用以下代码:

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());
}