@Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object o) throws Exception { String method = request.getMethod(); String requestURI = request.getRequestURI(); if (o instanceof ResourceHttpRequestHandler || o instanceof ParameterizableViewController) { return true; } String accessName = "无"; HandlerMethod handlerMethod = (HandlerMethod) o; ApiOperation methodAnnotation = handlerMethod.getMethodAnnotation(ApiOperation.class); if (Validator.valid(methodAnnotation)) { accessName = methodAnnotation.value(); log.warn("########## requestURI: {} , method: {} , HandlerMethod: {} , IP: {} ##########", requestURI, method, accessName, IPUtil.getIPAddress(request)); } else { log.error("########## requestURI: {} , HandlerMethod: {} , IP: {} ##########", requestURI, method, IPUtil.getIPAddress(request)); } for (String url : passUrl) { if (UrlUtils.isLike(requestURI, url)) { return !method.equals("OPTIONS"); } } boolean hasPerm = false; if (!method.equals("OPTIONS")) { try { String token = request.getHeader("token"); System.out.println("token -------->>>>>> " + token); if (!Validator.valid(token)) { throw new BusinessException(CommonErrorCode.TOKEN_REMIND, "token不能为空"); } token = (String) permRedisManager.get(token); if (!Validator.valid(token)) { throw new BusinessException(CommonErrorCode.TOKEN_REMIND, "请重新登录"); } Map<String, Claim> result = JWTBuilder.parseJWT(token); if (Validator.valid(result.get(AuthUtil.SYS_EMPLOYEE_NAME))) { // hasPerm = true; DepositBox depositBox = setAttribute(request, result, AuthUtil.SYS_EMPLOYEE_NAME, token); //操作记录 String finalAccessName = accessName; } else if ((Validator.valid(result.get(AuthUtil.MEMBER_NAME)))) { if (requestURI.startsWith("/bg")) { throw new BusinessException(CommonErrorCode.NO_SESSION); } hasPerm = true; setAttribute(request, result, AuthUtil.MEMBER_NAME, token); } } catch (BusinessException e) { throw e; } catch (Exception e) { if (e instanceof NullPointerException) { throw new BusinessException(CommonErrorCode.TOKEN_REMIND, "token无效"); } else if (e instanceof JWTDecodeException) { throw new BusinessException(CommonErrorCode.TOKEN_REMIND, "token信息不完整"); } else { throw new BusinessException(e.toString()); } } } if (!method.equals("OPTIONS") && !hasPerm) { throw new BusinessException(CommonErrorCode.NO_SESSION); } return !method.equals("OPTIONS"); }解释代码

这段代码是一个Java Spring框架中拦截器（Interceptor）的实现，用于拦截所有的请求，并对请求进行处理。当请求到达时，会先判断该请求是否是静态资源请求或者是视图控制器请求，如果是，则直接放行。如果不是，则获取该请求的ApiOperation注解，用于记录该请求的访问名称。接着，会判断该请求是否在白名单中，如果是，则检查请求是否为OPTIONS方法，如果是，则放行。如果不是，则会进行权限校验，根据请求头中的token获取用户信息，并进行JWT解析和验证。如果验证通过，则将用户信息存储到request中，并返回true，表示该请求通过拦截器的校验，可以进行后续的处理。如果请求不在白名单中，且权限校验未通过，则会抛出BusinessException异常，表示该请求被拦截，无法通过。

相关问题

HandlerInterceptor中的preHandle的参数handler怎么获取到目标方法并做入参的赋值

可以通过HandlerExecutionChain对象获取目标方法的信息，然后使用反射机制对目标方法的入参进行赋值。具体实现可以参考以下代码：

@Override
public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
    if (handler instanceof HandlerMethod) {
        HandlerMethod handlerMethod = (HandlerMethod) handler;
        Method method = handlerMethod.getMethod();
        Object[] args = new Object[method.getParameterTypes().length];
        Annotation[][] parameterAnnotations = method.getParameterAnnotations();
        for (int i = 0; i < parameterAnnotations.length; i++) {
            for (Annotation annotation : parameterAnnotations[i]) {
                if (annotation.annotationType().equals(RequestBody.class)) {
                    args[i] = readRequestBody(request, method.getParameterTypes()[i]);
                    break;
                } else if (annotation.annotationType().equals(RequestParam.class)) {
                    args[i] = readRequestParam(request, method.getParameterTypes()[i], method.getParameters()[i].getName());
                    break;
                } else if (annotation.annotationType().equals(RequestHeader.class)) {
                    args[i] = readRequestHeader(request, method.getParameterTypes()[i], method.getParameters()[i].getName());
                    break;
                } else if (annotation.annotationType().equals(PathVariable.class)) {
                    args[i] = readPathVariable(request, method.getParameterTypes()[i], ((PathVariable) annotation).value());
                    break;
                }
            }
        }
        request.setAttribute("args", args);
    }
    return true;
}

private Object readRequestBody(HttpServletRequest request, Class<?> clazz) throws IOException {
    String body = IOUtils.toString(request.getReader());
    return objectMapper.readValue(body, clazz);
}

private Object readRequestParam(HttpServletRequest request, Class<?> clazz, String paramName) {
    String value = request.getParameter(paramName);
    return conversionService.convert(value, clazz);
}

private Object readRequestHeader(HttpServletRequest request, Class<?> clazz, String headerName) {
    String value = request.getHeader(headerName);
    return conversionService.convert(value, clazz);
}

private Object readPathVariable(HttpServletRequest request, Class<?> clazz, String variableName) {
    String value = (String) request.getAttribute(HandlerMapping.URI_TEMPLATE_VARIABLES_ATTRIBUTE).get(variableName);
    return conversionService.convert(value, clazz);
}