Android利用HttpClient发送Json到后台

HttpPost httppost = new HttpPost(params[0]);

httppost.addHeader("Content-Type", "application/json;charset=utf-8");

httppost.setEntity(new StringEntity(str,"utf-8"));

HttpResponse response;

response = MyApplication.getInstance().getHttpclient().execute(httppost);

//检验状态码，如果成功接收数据
int code = response.getStatusLine().getStatusCode();

if (code == 200) {
HttpEntity entity = response.getEntity();

InputStream is = entity.getContent();

BufferedReader reader = new BufferedReader(new InputStreamReader(is));

String s = reader.readLine();
return s;
}
else return "error";

}  catch (Exception e) {
e.printStackTrace();
}

return "error";