问json android:如何阅读在线json格式

EN

HttpClient httpclient = new DefaultHttpClient();
    HttpPost httppost = new HttpPost("http://www.example.com/filter");

    try
    {
        HttpResponse response = httpclient.execute(httppost);
        InputStream in = response.getEntity().getContent();

byte [] buffer = new byte[in.available()];
        while (in.read(buffer) != -1);
        String jsontext = new String(buffer);
        JSONArray entries = new JSONArray(jsontext);
for (i=0;i<entries.length();i++)
        {
            JSONObject post = entries.getJSONObject(i);
            if(post.getString("u")=="driver")
            {
            x="Success";
            }
        }

        txtResult.setText(x); // x is string
    }