解決HttpServletRequest無法獲取@RequestBody修飾的參數(shù)問題及分析

更新時間：2025年09月26日 09:10:38 作者：Spirit_NKlaus

Spring Boot中,@RequestBody讀取請求體后流關(guān)閉,導(dǎo)致Service層無法獲取,解決方案包括創(chuàng)建HTTP工具類、請求體復(fù)制包裝器及攔截器配置,確保請求體可重復(fù)讀取

HttpServletRequest無法獲取@RequestBody修飾的參數(shù)

在使用springboot設(shè)計controller時我們通常會在某個請求如post中使用@RequestBody來修飾參數(shù)如：

在一些特殊場景下，我們需要在service層的代碼去拿到當(dāng)前上下文請求（HttpServletRequest）中的一些信息如請求體，這個時候被@RequestBody所修飾的請求是無法獲取的。

原因如下：

1、請求體流只能讀取一次：Servlet 規(guī)范中，HttpServletRequest 的輸入流 (getInputStream()) 是單向的，一旦被 @RequestBody 讀取后，流就會關(guān)閉，無法再次讀取。

2、@RequestBody 優(yōu)先處理：Spring MVC 在處理控制器方法時，會先解析 @RequestBody，導(dǎo)致后續(xù)通過 HttpServletRequest 獲取請求體時為空。

下面簡單演示下解決方案：

一、先編寫一個http工具類用來讀取ServletRequest的內(nèi)容

import com.alibaba.fastjson.JSON;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.lang3.StringUtils;

import javax.servlet.ServletInputStream;
import javax.servlet.ServletRequest;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;
import java.util.List;

/**
 * http工具類
 */
@Slf4j
public class HttpUtils {
    /**
     * 從request獲取body的數(shù)據(jù)
     *
     * @param request 請求
     * @return body數(shù)據(jù)字符串
     */
    public static String getBodyStr(ServletRequest request) {
        StringBuilder sb = new StringBuilder();
        try {
            try (ServletInputStream inputStream = request.getInputStream()) {
                try (BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, StandardCharsets.UTF_8))) {
                    String line;
                    while ((line = reader.readLine()) != null) {
                        sb.append(line);
                    }
                }
            }
        } catch (Exception e) {
            log.error("get request body error: ", e);
        }
        return sb.toString();
    }

    /**
     * 從request獲取body的數(shù)據(jù)，并轉(zhuǎn)換成對象（適用于使用@RequestBody修飾的參數(shù)）
     *
     * @param request request 請求
     * @param clazz   對象類型
     * @return 對象
     */
    public static <T> T getBodyToObject(ServletRequest request, Class<T> clazz) {
        String bodyStr = getBodyStr(request);
        if (StringUtils.isBlank(bodyStr)) {
            return null;
        }
        return JSON.parseObject(bodyStr, clazz);
    }

    /**
     * 從request獲取body的數(shù)據(jù)，并轉(zhuǎn)換成集合對象（適用于使用@RequestBody修飾的參數(shù)）
     *
     * @param request request 請求
     * @param clazz   集合對象類型
     * @return 集合對象
     */
    public static <T> List<T> getBodyToList(ServletRequest request, Class<T> clazz) {
        String bodyStr = getBodyStr(request);
        if (StringUtils.isBlank(bodyStr)) {
            return null;
        }
        return JSON.parseArray(bodyStr, clazz);
    }
}

二、添加請求體復(fù)制包裝器

import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.BufferedReader;
import java.io.ByteArrayInputStream;
import java.io.IOException;
import java.io.InputStreamReader;
import java.nio.charset.StandardCharsets;

/**
 * 請求體復(fù)制包裝器
 */
public class BodyCopyWrapper extends HttpServletRequestWrapper {
    private byte[] requestBody;

    public BodyCopyWrapper(HttpServletRequest request) throws IOException {
        super(request);
        requestBody = HttpUtils.getBodyStr(request).getBytes(StandardCharsets.UTF_8);
    }

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

    @Override
    public ServletInputStream getInputStream() throws IOException {
        final ByteArrayInputStream basis = new ByteArrayInputStream(requestBody);
        return new ServletInputStream() {
            @Override
            public int read() throws IOException {
                return basis.read();
            }

            @Override
            public boolean isFinished() {
                return false;
            }

            @Override
            public boolean isReady() {
                return false;
            }

            @Override
            public void setReadListener(ReadListener readListener) {
            }
        };
    }

    public void setInputStream(byte[] body) {
        this.requestBody = body;
    }
}

三、添加請求攔截器配置類

import lombok.extern.slf4j.Slf4j;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.Ordered;

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

/**
 * 請求攔截器配置類
 */
@Slf4j
@Configuration
public class FilterConfig {
    @Bean
    public FilterRegistrationBean<RequestWrapperFilter> requestWrapperFilter() {
        FilterRegistrationBean<RequestWrapperFilter> bean = new FilterRegistrationBean<>();
        bean.setFilter(new RequestWrapperFilter());
        bean.addUrlPatterns("/*");
        bean.setOrder(Ordered.HIGHEST_PRECEDENCE);
        return bean;
    }

    public static class RequestWrapperFilter implements Filter {
        @Override
        public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws ServletException
                , IOException {
            ServletRequest requestWrapper = null;
            if (request instanceof HttpServletRequest) {
                requestWrapper = new BodyCopyWrapper((HttpServletRequest) request);
            }
            if (null == requestWrapper) {
                log.warn("未進行request包裝返回原來的request");
                chain.doFilter(request, response);
            } else {
                chain.doFilter(requestWrapper, response);
            }
        }
    }
}

四、業(yè)務(wù)代碼中使用方式

HttpServletRequest request = ((ServletRequestAttributes) (RequestContextHolder.currentRequestAttributes())).getRequest();
//轉(zhuǎn)對象
UserLoginDTO userLoginDTO = HttpUtils.getBodyToObject(request, UserLoginDTO.class);
//直接獲取內(nèi)容字符串
String bodyStr = HttpUtils.getBodyStr(request);