导航：首页 > 开发技术 >

如何解决SpringBoot v2.2以上重复读取Request Body内容

发表于：2025-01-20 作者：千家信息网编辑

千家信息网最后更新 2025年01月20日，这篇文章主要介绍"如何解决SpringBoot v2.2以上重复读取Request Body内容"，在日常操作中，相信很多人在如何解决SpringBoot v2.2以上重复读取Request Body

千家信息网最后更新 2025年01月20日如何解决SpringBoot v2.2以上重复读取Request Body内容

这篇文章主要介绍"如何解决SpringBoot v2.2以上重复读取Request Body内容"，在日常操作中，相信很多人在如何解决SpringBoot v2.2以上重复读取Request Body内容问题上存在疑惑，小编查阅了各式资料，整理出简单好用的操作方法，希望对大家解答"如何解决SpringBoot v2.2以上重复读取Request Body内容"的疑惑有所帮助！接下来，请跟着小编一起来学习吧！

SpringBoot v2.2以上重复读取Request Body内容

一、需求

项目有两个场景会用到从Request的Body中读取内容。

打印请求日志
提供Api接口，在api方法执行前，从Request Body中读取参数进行验签，验签通过后在执行api方法

二、解决方案

2.1 自定义RequestWrapper

public class MyRequestWrapper extends HttpServletRequestWrapper { private final String body; public MyRequestWrapper(HttpServletRequest request) throws IOException {  super(request);  this.body = RequestReadUtils.read(request); } public String getBody() {  return body; } @Override public ServletInputStream getInputStream() throws IOException {  final ByteArrayInputStream bais = new ByteArrayInputStream(body.getBytes());    return new ServletInputStream() {   ...略  }; } @Override public BufferedReader getReader() throws IOException {  return new BufferedReader(new InputStreamReader(this.getInputStream())); }}

RequestReadUtils（网上抄的）

private static final int BUFFER_SIZE = 1024 * 8;      public static String read(HttpServletRequest request) throws IOException {        BufferedReader bufferedReader = request.getReader();        for (Enumeration iterator = request.getHeaderNames(); iterator.hasMoreElements();) {         String type = iterator.nextElement();   System.out.println(type+" = "+request.getHeader(type));  }        System.out.println();        StringWriter writer = new StringWriter();        write(bufferedReader,writer);        return writer.getBuffer().toString();    }     public static long write(Reader reader,Writer writer) throws IOException {        return write(reader, writer, BUFFER_SIZE);    }     public static long write(Reader reader, Writer writer, int bufferSize) throws IOException    {        int read;        long total = 0;        char[] buf = new char[bufferSize];        while( ( read = reader.read(buf) ) != -1 ) {            writer.write(buf, 0, read);            total += read;        }        return total;    }

2.2 定义Filter

@WebFilterpublic class TestFilter implements Filter{ @Override public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain chain){  HttpServletRequest request = (HttpServletRequest) servletRequest;  HttpServletResponse response = (HttpServletResponse) servletResponse;    MyRequestWrapper wrapper = WebUtils.getNativeRequest(request, MyRequestWrapper.class);  chain.doFilter(wrapper == null ? new MyRequestWrapper(request) :wrapper,servletRequest); }}

三、遇到问题

使用的SpringBoot v2.1.x版本

Form提交无问题
获取RequestBody无问题

使用SpringBoot v2.2.0以上版本（包括v2.3.x）

Form提交无法获取参数
获取RequestBody无问题

四、问题排查

经过排查，v2.2.x对比v2.1.x的不同在于一下代码差异：

BufferedReader bufferedReader = request.getReader();-----------------char[] buf = new char[bufferSize];while( ( read = reader.read(buf) ) != -1 ) {    writer.write(buf, 0, read);    total += read;}

当表单提交时

v2.1.x无法read到内容，读取结果为-1
v2.2.x、v2.3.x能够读取到内容

当表单提交时（x-www-form-urlencoded），inputStream读取一次后后续不会触发wrapper的getInputStream操作，所以Controller无法获取到参数。

解决方案

MyRequestWrapper改造

public class MyRequestWrapper extends HttpServletRequestWrapper { private final String body; public MyRequestWrapper(HttpServletRequest request) throws IOException {  super(request);  this.body = getBodyString(request); } public String getBody() {  return body; }  public String getBodyString(final HttpServletRequest request) throws IOException {     String contentType = request.getContentType();     String bodyString = "";     StringBuilder sb = new StringBuilder();     if (StringUtils.isNotBlank(contentType) && (contentType.contains("multipart/form-data") || contentType.contains("x-www-form-urlencoded"))) {         Map parameterMap = request.getParameterMap();         for (Map.Entry next : parameterMap.entrySet()) {             String[] values = next.getValue();             String value = null;             if (values != null) {                 if (values.length == 1) {                     value = values[0];                 } else {                     value = Arrays.toString(values);                 }             }             sb.append(next.getKey()).append("=").append(value).append("&");         }         if (sb.length() > 0) {             bodyString = sb.toString().substring(0, sb.toString().length() - 1);         }         return bodyString;     } else {         return IOUtils.toString(request.getInputStream());     } } @Override public ServletInputStream getInputStream() throws IOException {  final ByteArrayInputStream bais = new ByteArrayInputStream(body.getBytes());    return new ServletInputStream() {   @Override   public boolean isFinished() {    return false;   }   @Override   public boolean isReady() {    return false;   }   @Override   public int read() {    return bais.read();   }   @Override   public void setReadListener(ReadListener readListener) {   }  }; } @Override public BufferedReader getReader() throws IOException {  return new BufferedReader(new InputStreamReader(this.getInputStream())); }}

Springboot读取Request参数的坑

后端拿参数相关

默认配置时，

getInputStream()和getReader()一起使用会报错

使用两遍getInputStream()，第二遍会为空

当存在@RequestBody等注解时，springMVC已读取过一遍流，默认单独使用getInputStream()或getReader()都为空。

解决：写filter继承HttpServletRequestWrapper，缓存InputStream，覆盖getInputStream()和getReader()方法，使用ByteArrayInputStream is = new ByteArrayInputStream(body.getBytes());读取InputStream。

注意：springboot中，过滤器只需@Component即可生效，另外可在FilterRegistrationBean中配置路径和优先级。

对于拦截器，必须在InterceptorRegistry中调用addInterceptor方法。（路径可链式添加）