从request中获取请求json格式的参数信息

 所有的请求都存在于HttpServletRequest对象中，那么只需要在此对象中获取即可：

关键部分是代码中获取参数的地方，从request对象中获取流，再转成json字符串。

不只限于controller中，其他地方也可以使用此方法获取，前提是先得到request对象。

@RequestMapping("/user")
public class UserController {

    //获取参数
    public static JSONObject getParameters(HttpServletRequest request) throws IOException {
        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());
        return jsonObject;
    }

    @PostMapping("/param")
    public void getParam(HttpServletRequest request) throws IOException {
        getParameters(request);
    }

}

最近有一个需要从拦截器中获取post请求的参数的需求，这里记录一下处理过程中出现的问题。
首先想到的就是request.getParameter(String )方法，但是这个方法只能在get请求中取到参数，post是不行的，后来想到了使用流的方式，调用request.getInputStream()获取流，然后从流中读取参数，如下代码所示：

最近有一个需要从拦截器中获取post请求的参数的需求，这里记录一下处理过程中出现的问题。
首先想到的就是request.getParameter(String )方法，但是这个方法只能在get请求中取到参数，post是不行的，后来想到了使用流的方式，调用request.getInputStream()获取流，然后从流中读取参数，如下代码所示：

String body = "";
StringBuilder stringBuilder = new StringBuilder();
BufferedReader bufferedReader = null;
InputStream inputStream = null;
try {
    inputStream = request.getInputStream();
    if (inputStream != null) {
        bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
        char[] charBuffer = new char[128];
        int bytesRead = -1;
        while ((bytesRead = bufferedReader.read(charBuffer)) > 0) {
            stringBuilder.append(charBuffer, 0, bytesRead);
        }
    } else {
        stringBuilder.append("");
    }
} catch (IOException ex) {
    e.printStackTrace();
} finally {
    if (inputStream != null) {
        try {
            inputStream.close();
        }
        catch (IOException e) {
            e.printStackTrace();
        }
    }
    if (bufferedReader != null) {
        try {
            bufferedReader.close();
        }
        catch (IOException e) {
            e.printStackTrace();
        }
    }
}
body = stringBuilder.toString();

代码中的body就是request中的参数，我这里传的是JSON数据：{"page": 1, "pageSize": 10}，那么body就是：body = "{"page": 1, "pageSize": 10}"，一个JSON字符串。这样是可以成功获取到post请求的body，但是，经过拦截器后，参数经过@RequestBody注解赋值给controller中的方法的时候，却抛出了一个这样的异常：

    org.springframework.http.converter.HttpMessageNotReadableException: Required request body is missing

作者：woniu95
链接：https://www.jianshu.com/p/69c6fba08c92
来源：简书
著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。

import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.*;

public class RequestWrapper extends HttpServletRequestWrapper {
    private final String body;

    public RequestWrapper(HttpServletRequest request) {
        super(request);
        StringBuilder stringBuilder = new StringBuilder();
        BufferedReader bufferedReader = null;
        InputStream inputStream = null;
        try {
            inputStream = request.getInputStream();
            if (inputStream != null) {
                bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
                char[] charBuffer = new char[128];
                int bytesRead = -1;
                while ((bytesRead = bufferedReader.read(charBuffer)) > 0) {
                    stringBuilder.append(charBuffer, 0, bytesRead);
                }
            } else {
                stringBuilder.append("");
            }
        } catch (IOException ex) {

        } finally {
            if (inputStream != null) {
                try {
                    inputStream.close();
                }
                catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (bufferedReader != null) {
                try {
                    bufferedReader.close();
                }
                catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        body = stringBuilder.toString();
    }

    @Override
    public ServletInputStream getInputStream() throws IOException {
        final ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(body.getBytes());
        ServletInputStream servletInputStream = new ServletInputStream() {
            @Override
            public boolean isFinished() {
                return false;
            }
            @Override
            public boolean isReady() {
                return false;
            }
            @Override
            public void setReadListener(ReadListener readListener) {
            }
            @Override
            public int read() throws IOException {
                return byteArrayInputStream.read();
            }
        };
        return servletInputStream;

    }

    @Override
    public BufferedReader getReader() throws IOException {
        return new BufferedReader(new InputStreamReader(this.getInputStream()));
    }

    public String getBody() {
        return this.body;
    }

}

package com.miniprogram.web.douyin.interceptor;

import com.alibaba.fastjson.JSON;
import com.miniprogram.api.douyin.user.req.DyuserReq;
import com.miniprogram.common.auth.VisitLimitCount;
import com.miniprogram.common.cache.RedisCache;
import com.miniprogram.common.config.InterceptorConfigMap;
import com.miniprogram.common.config.InterceptorUrlConfig;
import com.miniprogram.common.douyin.SearchEngineMapConstants;
import com.miniprogram.common.response.Response;
import com.miniprogram.common.session.*;
import com.miniprogram.common.utils.DateUtil;
import com.miniprogram.dao.common.UserLoginEntity.Users;
import com.miniprogram.service.douyin.users.UsersService;
import com.miniprogram.web.douyin.config.RequestWrapper;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.BeanUtils;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

@Component("authSecurityInterceptor")
public class AuthSecurityInterceptor extends HandlerInterceptorAdapter {
    private Logger logger = LoggerFactory.getLogger(AuthSecurityInterceptor.class);

    @Autowired
    private UsersService douYinUsersService;
    @Autowired
    private RedisCache redisCache;
    @Autowired
    private VisitLimitCount visitLimitCount;

    @Override
    public boolean preHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o) throws Exception {
        try {
            RequestWrapper requestWrapper = new RequestWrapper(httpServletRequest);
            String body = requestWrapper.getBody();
            System.out.println(body);
            return true;
        }catch (Exception e){
            logger.error("权限判断出错",e);
        }
        return false;
    }

    @Override
    public void postHandle(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, ModelAndView modelAndView) throws Exception {

    }

    @Override
    public void afterCompletion(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) throws Exception {
    }
}

import com.miniprogram.web.douyin.config.RequestWrapper;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;

@Component
@WebFilter(urlPatterns = "/*",filterName = "channelFilter")
public class ChannelFilter implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }
 
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        ServletRequest requestWrapper = null;
        if(servletRequest instanceof HttpServletRequest) {
            requestWrapper = new RequestWrapper((HttpServletRequest) servletRequest);
        }
        if(requestWrapper == null) {
            filterChain.doFilter(servletRequest, servletResponse);
        } else {
            filterChain.doFilter(requestWrapper, servletResponse);
        }
    }
 
    @Override
    public void destroy() {

    }
}

import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.web.servlet.MultipartConfigFactory;
import org.springframework.boot.web.servlet.ServletComponentScan;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@SpringBootApplication
@ServletComponentScan  //注册过滤器注解
@Configuration
public class WebApplication {

    public static void main(String[] args) {
        SpringApplication.run(WebApplication.class, args);
    }
}