Spring MVC 实现request请求体多次读取_springmvc handlerinterceptor 重新读取request值

项目中有些场景可能需要多次读取requestBody的内容，如日志打印，参数校验，而HttpServletRequest对象中的数据流只能读取一次，再次读取就会抛出异常，因此我们需要自定义request包装类实现多次读取请求体内容。

正常情况下，controller接口只能申明一次@RequestBody，写多个会报错。原因就是request请求体的流对象只能单次读取。

1.自定义包装类

public class RequestWrapper extends HttpServletRequestWrapper {

    //参数字节数组
    private byte[] requestBody;

    //Http请求对象
    private HttpServletRequest request;

    public RequestWrapper(HttpServletRequest request) {
        super(request);
        this.request = request;
    }
    @Override
    public ServletInputStream getInputStream() throws IOException {
        /**
         * 每次调用此方法时将数据流中的数据读取出来，然后再回填到InputStream之中
         * 解决通过@RequestBody和@RequestParam（POST方式）读取一次后控制器拿不到参数问题
         */
        if (null == this.requestBody) {
            ByteArrayOutputStream baos = new ByteArrayOutputStream();
            IOUtils.copy(request.getInputStream(), baos);
            this.requestBody = baos.toByteArray();
        }

        final ByteArrayInputStream bais = new ByteArrayInputStream(requestBody);
        return new ServletInputStream() {

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

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

            @Override
            public void setReadListener(ReadListener listener) {
            }

            @Override
            public int read() {
                return bais.read();
            }
        };
    }

    public byte[] getRequestBody() {
        return requestBody;
    }

    @Override
    public BufferedReader getReader() throws IOException {
        return new BufferedReader(new InputStreamReader(this.getInputStream()));
    }
}
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2. 新增过滤器对HttpServletRequest进行包装

@WebFilter(urlPatterns = "/*")
public class RequestWrapperFilter implements Filter {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        try {
            if(!(servletRequest instanceof HttpServletRequest)){
                filterChain.doFilter(servletRequest, servletResponse);
                return;
            }
            //将改为我们定义的包装类
            ServletRequest requestWrapper = new RequestWrapper((HttpServletRequest) servletRequest);
            filterChain.doFilter(requestWrapper, servletResponse);
        } catch (IOException | ServletException e) {
            e.printStackTrace();
        }
    }
}
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3. 测试

经过以上配置，接口参数就可以写多个RequestBody了

@PostMapping("/post")
public Object postTest(@RequestBody Book book,@RequestBody Book book2){
    log.info("controller----->,{}",book);
    return book;
}
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