从HttpServletRequest中获取body中的参数几种方式

从HttpServletRequest中如何获取body中的参数？

一、

Map<String,Object> params = new HashMap<String, Object>();
        BufferedReader br;
        try {
            br = request.getReader();
            String str, wholeParams = "";
            while((str = br.readLine()) != null){
                wholeParams += str;
            }
            if(StringUtils.isNotBlank(wholeParams)){
                params = JSON.parseObject(wholeParams,Map.class);
            }
        } catch (IOException e) {
            logger.error("",e);
        }
二、servlet中获取

import com.alibaba.dubbo.common.utils.IOUtils;
public class BusinessServlet extends HttpServlet{

 public static final Logger log = Logger.getLogger(BusinessServlet.class);

 private static final long serialVersionUID = 1L;

 private static BusinessService service;

 static{

 service = (BusinessService) WebContext.getBean("businessService");

 }

 @Override

 protected void doGet(HttpServletRequest req, HttpServletResponse resp)

  throws ServletException, IOException {

 doPost(req, resp);

 }

 @Override

 protected void doPost(HttpServletRequest req, HttpServletResponse res)

  throws ServletException, IOException {

 BufferedReader reader = new BufferedReader(new InputStreamReader(req.getInputStream()));

 String body = IOUtils.read(reader);

 String name = req.getParameter("name");

 if(StringUtils.isNotBlank(body)){
  log.info("business receive somthing with body :"+body);
 }
 res.setCharacterEncoding("UTF-8");
 res.setContentType("application/json");
 res.setStatus(HttpServletResponse.SC_OK);
 res.getWriter().println(service.getName(name));
 }
}

三、

public class HttpServletRequestReader
{
 
    // 字符串读取
    // 方法一
    public static String ReadAsChars(HttpServletRequest request)
    {
 
        BufferedReader br = null;
        StringBuilder sb = new StringBuilder("");
        try
        {
            br = request.getReader();
            String str;
            while ((str = br.readLine()) != null)
            {
                sb.append(str);
            }
            br.close();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        finally
        {
            if (null != br)
            {
                try
                {
                    br.close();
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
        }
        return sb.toString();
    }
 
    // 方法二
    public static void ReadAsChars2(HttpServletRequest request)
    {
        InputStream is = null;
        try
        {
            is = request.getInputStream();
            StringBuilder sb = new StringBuilder();
            byte[] b = new byte[4096];
            for (int n; (n = is.read(b)) != -1;)
            {
                sb.append(new String(b, 0, n));
            }
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        finally
        {
            if (null != is)
            {
                try
                {
                    is.close();
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
        }
 
    }
 
    // 二进制读取
    public static byte[] readAsBytes(HttpServletRequest request)
    {
 
        int len = request.getContentLength();
        byte[] buffer = new byte[len];
        ServletInputStream in = null;
 
        try
        {
            in = request.getInputStream();
            in.read(buffer, 0, len);
            in.close();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        finally
        {
            if (null != in)
            {
                try
                {
                    in.close();
                }
                catch (IOException e)
                {
                    e.printStackTrace();
                }
            }
        }
        return buffer;
    }
}

PS：
HttpServletRequest 请求中的 body 内容仅能调用 request.getInputStream()， request.getReader()和request.getParameter("key") 方法读取一次，重复读取会报 java.io.IOException: Stream closed 异常。