话不多说，先看代码！
/** * Created by david on 2017-7-5. */import com.google.gson.JsonObject;import com.google.gson.JsonParser;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStream;import java.io.InputStreamReader;import java.net.HttpURLConnection;import java.net.URL;public class HttpRequestUtil { /** * 发起http请求并获取结果 * @param requestUrl 请求地址 */ public static JsonObject getXpath(String requestUrl){ String res=""; JsonObject object = null; StringBuffer buffer = new StringBuffer(); try{ URL url = new URL(requestUrl); HttpURLConnection urlCon= (HttpURLConnection)url.openConnection(); if(200==urlCon.getResponseCode()){ InputStream is = urlCon.getInputStream(); InputStreamReader isr = new InputStreamReader(is,"utf-8"); BufferedReader br = new BufferedReader(isr); String str = null; while((str = br.readLine())!=null){ buffer.append(str); } br.close(); isr.close(); is.close(); res = buffer.toString(); JsonParser parse =new JsonParser(); object = (JsonObject) parse.parse(res); } }catch(IOException e){ e.printStackTrace(); } return object; } public static JsonObject postDownloadJson(String path,String post){ URL url = null; try { url = new URL(path); HttpURLConnection httpURLConnection = (HttpURLConnection) url.openConnection(); httpURLConnection.setRequestMethod("POST");// 提交模式 // conn.setConnectTimeout(10000);//连接超时 单位毫秒 // conn.setReadTimeout(2000);//读取超时 单位毫秒 // 发送POST请求必须设置如下两行 httpURLConnection.setDoOutput(true); httpURLConnection.setDoInput(true); // 获取URLConnection对象对应的输出流 PrintWriter printWriter = new PrintWriter(httpURLConnection.getOutputStream()); // 发送请求参数 printWriter.write(post);//post的参数 xx=xx&yy=yy // flush输出流的缓冲 printWriter.flush(); //开始获取数据 BufferedInputStream bis = new BufferedInputStream(httpURLConnection.getInputStream()); ByteArrayOutputStream bos = new ByteArrayOutputStream(); int len; byte[] arr = new byte[1024]; while((len=bis.read(arr))!= -1){ bos.write(arr,0,len); bos.flush(); } bos.close(); JsonParser parse = new JsonParser(); return (JsonObject)parse.parse(bos.toString("utf-8")); } catch (Exception e) { e.printStackTrace(); } return null; } //测试 public static void main(String args [] ) { JsonObject res = null; // res = getXpath("http://ip.taobao.com/service/getIpInfo.php?ip=63.223.108.42"); res = postDownloadJson("http://ip.taobao.com/service/getIpInfo.php?ip=63.223.108.42","123"); System.out.println(res); System.out.println(res.get("code")); System.out.println(res.get("data")); }}看第一个方法，发送get请求获取后台数据，其中，将返回回来的字符串解析成json对象用到了google的Gson.jar包，用到了其中JsonParser的parse方法。
第二个方法，发送post数据到后台并获取后台数据。
以上这篇java发起http请求获取返回的Json对象方法就是小编分享给大家的全部内容了，希望能给大家一个参考，也希望大家多多支持武林网。