HttpURLConnection类的使用
此类以获取天气的一个api地址为例:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
package javaexcjs; import java.io.BufferedReader; import java.io.OutputStreamWriter; import java.io.InputStream; import java.io.InputStreamReader; import java.net.HttpURLConnection; import java.net.URLEncoder; import java.net.URL; import java.util.List; import java.util.Map; import java.util.Set; public class CopyOfSendPostRequest { static String sessionId = ""; public static void main(String[] args) throws Exception { //城市名称 String city = URLEncoder.encode("重庆", "GB2312"); System.out.println(city); // api url :北向URL String locationUrl = "http://php.weather.sina.com.cn/xml.php?city=" + city + "&password=DJOYnieT8234jlsK&day=0"; // http body 消息体 String reqBody = ""; // http method String method = "POST"; // http head : Content-Type 消息类型 String contentType = "application/json;charset=UTF-8"; // 设定连接的相关参数 URL url = new URL(locationUrl); HttpURLConnection connection = (HttpURLConnection) url.openConnection(); connection.setDoOutput(true); connection.setReadTimeout(10000); connection.setRequestMethod(method); connection.setRequestProperty("Content-Type", contentType); //写入请求消息体 OutputStreamWriter out = new OutputStreamWriter( connection.getOutputStream(), "UTF-8"); out.write(reqBody); out.flush(); out.close(); // 获取服务端的反馈 String strLine = ""; StringBuilder strResponse = new StringBuilder(); try { Map<String, List<String>> rspHeaders = connection.getHeaderFields(); Set<String> rspHeadNames = rspHeaders.keySet(); for (String key : rspHeadNames) { //rspHeaders中的http状态码和描述的键为null if (null != key) { strResponse.append(key + ": "); } strResponse.append(new String(rspHeaders.get(key).get(0) .getBytes("iso-8859-1"), "UTF-8") + "\n"); } int code = connection.getResponseCode(); // String status = connection.getResponseMessage(); InputStream in; // 判断http状态码 if (code == 200) { in = connection.getInputStream(); } else { in = connection.getErrorStream(); } if (null != in) { BufferedReader reader = new BufferedReader( new InputStreamReader(in)); while ((strLine = reader.readLine()) != null) { strResponse.append("\n" + strLine); } } System.out.print(strResponse.toString()); } catch (Exception e) { e.printStackTrace(); } } }