个人学习系列 - 解决拦截器操作请求参数后台无法获取

由于项目需要使用拦截器对请求参数进行操作，可是请求流只能操作一次，导致后面方法不能再获取流了。

新建SpringBoot项目

1. 新建拦截器WebConfig.java

/*** @date: 2023/2/6 11:21* @author: zhouzhaodong* @description:*/
@Configuration
public class WebConfig implements WebMvcConfigurer {/*** 添加Web项目的拦截器*/@Overridepublic void addInterceptors(InterceptorRegistry registry) {// 对所有访问路径，都通过MyInterceptor类型的拦截器进行拦截// 放行登录页，登陆操作，静态资源registry.addInterceptor(new MyInterceptor()).addPathPatterns("/**").excludePathPatterns("/", "/login", "/index.html", "/user/login", "/css/**", "/images/**", "/js/**", "/fonts/**");}
}

2. 获取请求参数并处理逻辑

/*** @date: 2023/2/6 12:46* @author: zhouzhaodong* @description: 获取请求参数并处理*/
public class RequestWrapper extends HttpServletRequestWrapper {private final Logger logger = LoggerFactory.getLogger(RequestWrapper.class);private final byte[] body;public RequestWrapper(HttpServletRequest request) {super(request);String sessionStream = getBodyString(request);body = sessionStream.getBytes(StandardCharsets.UTF_8);}public String getBodyString() {return new String(body, StandardCharsets.UTF_8);}/*** @date: 2023/2/6 12:46* @author: zhouzhaodong* @description: 获取请求Body*/public String getBodyString(final ServletRequest request) {StringBuilder sb = new StringBuilder();InputStream inputStream = null;BufferedReader reader = null;try {inputStream = cloneInputStream(request.getInputStream());reader = new BufferedReader(new InputStreamReader(inputStream, StandardCharsets.UTF_8));String line = "";while ((line = reader.readLine()) != null) {sb.append(line);}} catch (IOException e) {e.printStackTrace();} finally {if (inputStream != null) {try {inputStream.close();} catch (IOException e) {e.printStackTrace();}}if (reader != null) {try {reader.close();} catch (IOException e) {e.printStackTrace();}}}logger.info("获取body请求参数:" + sb);return sb.toString();}/*** @date: 2023/2/6 12:46* @author: zhouzhaodong* @description: 复制输入流*/public InputStream cloneInputStream(ServletInputStream inputStream) {ByteArrayOutputStream byteArrayOutputStream = new ByteArrayOutputStream();byte[] buffer = new byte[1024];int len;try {while ((len = inputStream.read(buffer)) > -1) {byteArrayOutputStream.write(buffer, 0, len);}byteArrayOutputStream.flush();} catch (IOException e) {e.printStackTrace();}return new ByteArrayInputStream(byteArrayOutputStream.toByteArray());}@Overridepublic BufferedReader getReader() {return new BufferedReader(new InputStreamReader(getInputStream()));}@Overridepublic ServletInputStream getInputStream() {final ByteArrayInputStream bais = new ByteArrayInputStream(body);return new ServletInputStream() {@Overridepublic int read() {return bais.read();}@Overridepublic boolean isFinished() {return false;}@Overridepublic boolean isReady() {return false;}@Overridepublic void setReadListener(ReadListener readListener) {}};}
}

3. 实现HandlerInterceptor接口

/*** @date: 2023/2/6 11:19* @author: zhouzhaodong* @description: 实现HandlerInterceptor接口*/public class MyInterceptor implements HandlerInterceptor {private final Logger logger = LoggerFactory.getLogger(MyInterceptor.class);/*** @date: 2023/2/6 11:19* @author: zhouzhaodong* @description: 访问控制器方法前执行*/@Overridepublic boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) {logger.info("================进入拦截器======================");logger.info(new Date() + "--preHandle:" + request.getRequestURL());logger.info("***************************【RequestBeginning】***************************");logger.info("----------------StartProcessingRequest----------------");try {long currentTime = System.currentTimeMillis();SimpleDateFormat formatter = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");Date date = new Date(currentTime);logger.info("CurrentTime: {}", formatter.format(date));logger.info("ResponseTime: {}", (System.currentTimeMillis() - currentTime) + "ms");String requestUrl = request.getRequestURI();logger.info("RequestURL: {} ", requestUrl);logger.info("GetMethod: {}", handler);String method = request.getMethod();logger.info("Method: {}", method);//获取请求参数RequestWrapper requestWrapper = new RequestWrapper(request);//这里getBodyString()方法无参数logger.info("RequestBody: {}", requestWrapper.getBodyString());} catch (Exception e) {logger.error("MVC业务处理-拦截器异常：", e);}logger.info("-------------------------End-------------------------");return true;}/*** @date: 2023/2/6 12:46* @author: zhouzhaodong* @description: 访问控制器方法后执行*/@Overridepublic void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) {logger.info(new Date() + "--postHandle:" + request.getRequestURL());}/*** @date: 2023/2/6 12:46* @author: zhouzhaodong* @description: postHandle方法执行完成后执行，一般用于释放资源*/@Overridepublic void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) {logger.info(new Date() + "--afterCompletion:" + request.getRequestURL());}
}

4. application.yml

spring:main:# 当出现相同名字的类进行注册时，准许覆盖注册allow-bean-definition-overriding: true

5. 启动类添加@ServletComponentScan注解

6. 新建TestController.java

/*** @date: 2023/2/6 12:24* @author: zhouzhaodong* @description: 测试*/
@RestController
public class TestController {@PostMapping("/one/abc")public String abc(@RequestBody User user){return user.getName();}
}

7. 不进行处理先测试看结果

请求结果：

控制台输出：

可以看出，流被读取了一次然后后台就获取不到了。

8. 通过过滤器获取参数然后传到后面程序中

/*** @date: 2023/2/6 12:47* @author: zhouzhaodong* @description:*/
@Component
@WebFilter(urlPatterns = "/*", filterName = "channelFilter")
public class ChannelFilter implements Filter {private final Logger logger = LoggerFactory.getLogger(ChannelFilter.class);@Overridepublic void init(FilterConfig filterConfig) {}@Overridepublic void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {logger.info("================进入过滤器======================");// 防止流读取一次后就没有了, 所以需要将流继续写出去HttpServletRequest httpServletRequest = (HttpServletRequest) servletRequest;RequestWrapper requestWrapper = new RequestWrapper(httpServletRequest);filterChain.doFilter(requestWrapper, servletResponse);}@Overridepublic void destroy() {}
}

9. 流处理后再进行测试

请求结果：

控制台输出：

解决啦！！！

源代码路径

https://github.com/zhouzhaodong/springboot/tree/master/springboot-interceptor