public class QueryHelper {

                                            /**
                                            * txt|jsonp|xml
                                            */
                                            public static String DATATYPE="text";
                                            
                                            public static String get(String urlString,String token) {
                                                try {
                                                    URL url = new URL(urlString);
                                                    HttpURLConnection conn = (HttpURLConnection) url.openConnection();
                                                    conn.setConnectTimeout(5 * 1000);
                                                    conn.setReadTimeout(5 * 1000);
                                                    conn.setDoInput(true);
                                                    conn.setDoOutput(true);
                                                    conn.setUseCaches(false);
                                                    conn.setInstanceFollowRedirects(false);
                                                    conn.setRequestMethod("GET"); 
                                                    conn.setRequestProperty("token",token);
                                                    int responseCode = conn.getResponseCode();
                                                    if (responseCode == 200) {
                                                        StringBuilder builder = new StringBuilder();
                                                        BufferedReader br = new BufferedReader(
                                                                new InputStreamReader(conn.getInputStream(),"utf-8"));
                                                        for (String s = br.readLine(); s != null; s = br
                                                                .readLine()) {
                                                            builder.append(s);
                                                        }
                                                        br.close();
                                                        return builder.toString();
                                                    }
                                                } catch (IOException e) {
                                                    e.printStackTrace();
                                                }
                                                return null;
                                            }
                                            public static String queryWeather(String code){
                                                String url="https://api.ip138.com/weather/?code="+code;
                                                String token="c1dd42049a489b73a39d4fcca47454f4";
                                                return get(url,token);
                                            }

                                        }

                                        //以下是使用示例：
                                        //QueryHelper.queryWeather("350103")