Android : JSON POST instead of PUT

I need to send put request to server, but my app is sending post request instead of it, I've tried to find the problem but I can't find any error public class JSON { public static JSON createEmpty(){ return new JSON("{}"); }

public static JSON createFromNet(String url){
    return JSON.createFromNet(url, "GET", "");
}

public static JSON createFromNet(String url, String method, JSON params){
    return JSON.createFromNet(url, method, params.toString());
}

public static JSON createFromNet(String url, String method, String params){
    String json = "{}";
    try{
        DefaultHttpClient httpClient = new DefaultHttpClient();
        HttpUriRequest httpRequest = null;
        if (method == "GET"){
            httpRequest = JSON.getGetRequest(url);
        }
        if (method == "PUT"){
            httpRequest = JSON.getPutRequest(url, params);  
        }
        if (httpRequest == null){ 
            throw new Exception();
        }
        httpRequest.setHeader("XXXXXXX", "XXXXXXX");

        HttpResponse httpResponse = httpClient.execute(httpRequest);
        HttpEntity httpEntity = httpResponse.getEntity();
        InputStream is = httpEntity.getContent();

        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 (UnsupportedEncodingException e) {
    }catch (ClientProtocolException e) {
    }catch (IOException e) { 
    }catch (Exception e) { 
    }

    return new JSON(json);
}

protected static HttpUriRequest getPutRequest(String url, String params) throws UnsupportedEncodingException{
    StringEntity input = new StringEntity(params);
    input.setContentType("application/json");
    input.setContentEncoding("UTF-8");

    HttpPut request = new HttpPut(url);
    request.setEntity(input);


    return request;
}

protected static HttpUriRequest getGetRequest(String url){
    return new HttpGet(url);
}

protected JSONObject json = null;

public JSON(String json_string){
    try {
        json = new JSONObject(json_string);
    } catch (JSONException e) {
        json = new JSONObject();
    }
}

public JSON(JSONObject json){
    this.json = json;
}

public int getInt(String key, int def){
    try{ return json.getInt(key); }
    catch (Exception e) { return def; }
}

public String getString(String key, String def){
    try{ return json.getString(key); }
    catch (Exception e) { return def; }
}

public double getDouble(String key, double def){
    try{ return json.getDouble(key); }
    catch (Exception e) { return def; }
}

public JSON getObject(String key){
    try{ return new JSON(json.getJSONObject(key));
    } catch (Exception e){ return new JSON("{}"); }
}

public ArrayList<JSON> getArray(String key){
    try{ 
        ArrayList<JSON> result = new ArrayList<JSON>();
        JSONArray json_array = json.getJSONArray(key);
        for (int i = 0; i < json_array.length(); i++){
            try{ result.add(new JSON(json_array.getJSONObject(i)));}
            catch (Exception e){}
        }
        return result;
    }
    catch (Exception e){
        return new ArrayList<JSON>();
    }
}

public String toString(){
    try{ return json.toString(); }
    catch (Exception e) { return "{}"; }    
}

public void putString(String key, String value){
    try{ json.put(key, value);}
    catch (Exception e) {}  
}

public void putInt(String key, Integer value){
    try{ json.put(key, value);}
    catch (Exception e) {}  
}

public void putDouble(String key, Double value){
    try{ json.put(key, value);}
    catch (Exception e) {}  
}

public void putObject(String key, JSON value){
    try{ 
        json.put(key, new JSONObject(value.toString()));
    }
    catch (Exception e) {}  
}

public void putArray(String key, ArrayList<JSON> value){
    try{ 
        JSONArray json_array = new JSONArray();
        for (int i = 0; i < value.size(); i++){
            json_array.put(new JSONObject(value.get(i).toString()));
        }
        json.put(key, json_array);}
    catch (Exception e) {}  
}
}