如何把前端传过来的Json对象解析出来？在java web应用中，我们如何获取post请求body中的内容？
通常利用request获取参数可以直接通过req.getParameter(name)的方式获取url上面或者ajax data提交上来的参数。但是body是没有名字的，无法通过参数名字这种方式获取。这时候需要用到io流的方式来获取body中的内容。
package com.example.controller; import java.io.BufferedReader;import java.io.InputStreamReader; import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse; import org.springframework.boot.autoconfigure.EnableAutoConfiguration;import org.springframework.web.bind.annotation.PathVariable;import org.springframework.web.bind.annotation.RequestMapping;import org.springframework.web.bind.annotation.RestController; import com.alibaba.fastjson.JSONObject; @RestController@EnableAutoConfigurationpublic class Example { ????@RequestMapping("/") ???String home() { ???????return "Hello World!"; ???} ???????????// 这里我没做异常处理 ???@RequestMapping("/request") ???String request(HttpServletRequest request, HttpServletResponse response) { ???????String param= null; ????????try { ???????????BufferedReader streamReader = new BufferedReader( new InputStreamReader(request.getInputStream(), "UTF-8")); ???????????StringBuilder responseStrBuilder = new StringBuilder(); ???????????String inputStr; ???????????while ((inputStr = streamReader.readLine()) != null) ???????????????responseStrBuilder.append(inputStr); ???????????????????????JSONObject jsonObject = JSONObject.parseObject(responseStrBuilder.toString()); ???????????param= jsonObject.toJSONString(); ???????????System.out.println(param); ???????} catch (Exception e) { ???????????e.printStackTrace(); ???????} ???????return param; ???} ????????????????????@RequestMapping("/hello/{myName}") ???String index(@PathVariable String myName) { ???????return "Hello " + myName + "!!!"; ???}}获取body参数，需要在request.getParameter()方法之前调用（如果有需要取QueryString参数的话），因为一旦调用了getParameter()方法之后，再通过IO流的方式获取body参数就失效了(亲测返回"")
参考：
1、http://blog.techbeta.me/2015/12/java-http-json/
2、https://blog.csdn.net/qq_27292113/article/details/76837603
通过HttpServletRequest转换获得json对象
原文地址：https://www.cnblogs.com/shengulong/p/9949891.html