org.apache.http.NoHttpResponseException: Le serveur cible n'a pas pu répondre

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.NameValuePair;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.entity.UrlEncodedFormEntity;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.client.utils.URLEncodedUtils;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.params.HttpProtocolParams;
public class JSONParser {
static InputStream is = null;
static JSONObject jObj = null;
static String json = "";
private final String TAG = "ACCESS";
//constructor
public JSONParser() {
}
//function get json from url
//by making HTTP POST or GET mehtod
public JSONObject makeHttpRequest(String url, String method,
List<NameValuePair> params) {
//Making HTTP request
try {
//check for request method
if(method.equals("POST")){
//request method is POST
//defaultHttpClient
DefaultHttpClient httpClient = new DefaultHttpClient();
HttpPost httpPost = new HttpPost(url);
httpPost.setEntity(new UrlEncodedFormEntity(params));
HttpResponse httpResponse = httpClient.execute(httpPost);
HttpEntity httpEntity = httpResponse.getEntity();
is = httpEntity.getContent();
}else if(method.equals("GET")){
//request method is GET
Log.e(TAG, "check1");
DefaultHttpClient httpClient = new DefaultHttpClient();
Log.e(TAG, "check2");
HttpProtocolParams.setUseExpectContinue(httpClient.getParams(), false);
Log.e(TAG, "check3");
String paramString = URLEncodedUtils.format(params, "utf-8");
Log.e(TAG, "check4");
url += "?" + paramString;
Log.e(TAG, "check5");
HttpGet httpGet = new HttpGet(url);
Log.e(TAG, "check6");
HttpResponse httpResponse = httpClient.execute(httpGet); //getting exception here
Log.e(TAG, "check7");
HttpEntity httpEntity = httpResponse.getEntity();
Log.e(TAG, "check8");
is = httpEntity.getContent();
Log.e(TAG, "check9");
}           
}
catch (UnsupportedEncodingException e) {
Log.e(TAG, "e1"+e.toString());
return null;
}
catch (ClientProtocolException e) {
Log.e(TAG, "e2"+e.toString());
return null;
}
catch (IOException e) {
Log.e(TAG, "e3"+e.toString());//this exception occurs
return null;
}
try {
BufferedReader reader = new BufferedReader(new InputStreamReader(
is, "iso-8859-1"), 8);
StringBuilder sb = new StringBuilder();
String line = null;
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
json = sb.toString();
} catch (Exception e) {
Log.e(TAG, "e4"+" Error converting result " + e.toString());
return null;
}
//try parse the string to a JSON object
try {
jObj = new JSONObject(json);
} catch (JSONException e) {
Log.e(TAG, "e5"+" Error parsing data " + e.toString());
return null;
}
//return JSON String
return jObj;
}
}

Quand je suis appelant le code ci-dessus avec un objet jParser de classe ci-dessus, il donne exception.

private final String GET_ALL_MODEL_NAME = "http://10.0.0.2/android_connect/get_all_model_name.php";
List<NameValuePair> params = new ArrayList<NameValuePair>();
//getting JSON string from URL
JSONObject json = jParser.makeHttpRequest(GET_ALL_MODEL_NAME, "GET", params);

Je suis l'exception. mon logcat est

02-23 03:52:55.702: E/ACCÈS(1603): check1

02-23 03:52:55.732: E/ACCÈS(1603): check2

02-23 03:52:55.732: E/ACCÈS(1603): check3

02-23 03:52:55.742: E/ACCÈS(1603): check4

02-23 03:52:55.742: E/ACCÈS(1603): check5

02-23 03:52:55.792: E/ACCÈS(1603): check6

02-23 03:56:22.442: E/ACCÈS(1603): e3org.apache.http.NoHttpResponseException: Le serveur cible n'a pas pu répondre

S'il vous plaît aider, comme je l'ai googlé mais ne trouvez rien d'utile