java 获取request中的请求参数

1、get 和 post请求方式

（1）request.getParameterNames(); 获取所有参数key后。遍历request.getParameter(key)获取value

（2）request.getParameterMap() 。直接包含参数key和value值，简单方便

Map<String, String[]>maps =  request.getParameterMap();

for (Map.Entry<String, String[]> entry : maps.entrySet()) {
     String cs = entry.getKey() + ":"+Arrays.toString(entry.getValue())+";";
}

2、获取请求类型为request  payload方式

这里就不介绍文件流的了，主要针对 后端采用@RequestBody方式的请求

这类数据通过以上2种方式是获取不到的，它是存放在流里面，要通过getInputStream()或getReader()方式获取

public String getRequestData(HttpServletRequest httpServletRequest){
        HttpServletRequestWrapper httpServletRequestWrapper = new HttpServletRequestWrapper(httpServletRequest);
        StringBuilder sb = new StringBuilder();
        BufferedReader reader = null;
        InputStreamReader inputStreamReader=null;
        ServletInputStream servletInputStream =null;
        try {
            servletInputStream =  httpServletRequestWrapper.getInputStream();
            inputStreamReader=new InputStreamReader (servletInputStream, Charset.forName("UTF-8"));
            reader = new BufferedReader(inputStreamReader);
            String line = "";
            while ((line = reader.readLine()) != null) {
                sb.append(line);
            }
        } catch (IOException e) {
            return "";
        }finally {
            try {
                if(servletInputStream!=null){
                    servletInputStream.close();
                }
                if(inputStreamReader!=null){
                    inputStreamReader.close();
                }
                if(reader!=null){
                    reader.close();
                }
            } catch (IOException e) {

            }
        }
        return sb.toString ();
    }

需要注意的是getInputStream()这种获取流的方式  只能用一次，如果多次调用  需要缓存起来，不然流的数据到不了Controller层，报400错误