问Android Java UTF-8 HttpClient问题

EN

HttpParams params = new BasicHttpParams();
HttpProtocolParams.setVersion(params, HttpVersion.HTTP_1_1);
HttpProtocolParams.setContentCharset(params, "utf-8");
params.setBooleanParameter("http.protocol.expect-continue", false);

HttpClient httpclient = new DefaultHttpClient(params);

HttpGet httpget = new HttpGet("http://www.example.com/json_array.php");
HttpResponse response;
    try {
        response = httpclient.execute(httpget);

        if(response.getStatusLine().getStatusCode() == 200){
            // Connection was established. Get the content. 

            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 jsonText = convertStreamToString(instream);

                Toast.makeText(getApplicationContext(), "Response: "+jsonText, Toast.LENGTH_LONG).show();

            }

        }


    } catch (MalformedURLException e) {
        Toast.makeText(getApplicationContext(), "ERROR: Malformed URL - "+e.getMessage(), Toast.LENGTH_LONG).show();
        e.printStackTrace();
    } catch (IOException e) {
        Toast.makeText(getApplicationContext(), "ERROR: IO Exception - "+e.getMessage(), Toast.LENGTH_LONG).show();
        e.printStackTrace();
    } catch (JSONException e) {
        Toast.makeText(getApplicationContext(), "ERROR: JSON - "+e.getMessage(), Toast.LENGTH_LONG).show();
        e.printStackTrace();
    }

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;
    try {
        reader = new BufferedReader(new InputStreamReader(is, "UTF-8"));
    } catch (UnsupportedEncodingException e1) {
        // TODO Auto-generated catch block
        e1.printStackTrace();
    }
    StringBuilder sb = new StringBuilder();

    String line;
    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();
}