springMVC @ResponseBody HandlerInterceptor ModelAndView null

今天springMVC开发遇到一个问题就是：

用了@RestController或者@ResponseBody注解之后，再用拦截器拦截（ HandlerInterceptor）的时候，里面的 postHandle 的方法的参数ModelAndView 不管怎么弄都是null，很纠结，看了官网文档才知道加了这2个注解其实就不走视图转换而是走的这个类RequestResponseBodyMethodProcessor。

解决办法是加一个切面，然后在切面里面设置返回的参数到request（也可以设置到ThreadLocal）里面然后拦截器里面在从request或者ThreadLocal里拿即可

切面类如下

@Aspect
@Component
public class GateWayAOP {
    private  ThreadLocal entityThreadLocal=new ThreadLocal();
    //Controller层切点路径
    @Pointcut("execution(* com.yihu.wlyy.web..*.*(..))")
    public void controllerAspect() {
    }


    public GateWayAOP() {
        //System.out.println("Observer---------------------------------------");
    }


    @Around("controllerAspect()")
    public Object checkToken(ProceedingJoinPoint point) throws Throwable {
        Object obj = null;
        HttpServletRequest request = ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();
        try {
            obj = point.proceed();

        }catch (Exception e){
            e.printStackTrace();
        }
        request.setAttribute("returnObj",obj);//先把结果放进
        return obj;
    }
}

拦截器里面拿

@Component
public class GateWayInterceptor implements HandlerInterceptor {

    private Logger logger = LoggerFactory.getLogger(GateWayInterceptor.class);
    @Autowired
    private GcHttpLogDao httpLogDao;
    @Autowired
    private GcTokenDao gcTokenDaoDao;


    /**
     * preHandle：预处理回调方法
     *
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        return true;
    }

    /**
     * 后处理回调方法
     *
     * @param request
     * @param response
     * @param handler
     * @param modelAndView
     * @throws Exception
     */
    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {
        String output = "";
        if (modelAndView != null) {
            output = JSONObject.fromObject(modelAndView.getModelMap()).toString();
        } else {
            Object returnObj = request.getAttribute("returnObj"); //再把结果放进
            if (returnObj != null) {
                output = JSONObject.fromObject(returnObj).toString();  
            }
        }
        HandlerMethod handlerMethod = (HandlerMethod) handler;
//        response.getOutputStream()
        String token = request.getHeader("accesstoken");
        String ip = NetworkUtil.getIpAddress(request);


        saveHttpLog(ip,
                JSONObject.fromObject(request.getParameterMap()).toString(),
                output,
                token,
                request.getRequestURI(),
                GcHttpLog.flagEm.success.getCode(),
                null);
    }

    /**
     * 整个请求处理完毕回调方法
     *
     * @param request
     * @param response
     * @param handler
     * @param ex
     * @throws Exception
     */
    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

    }

}

这边要注意的是

因为每次请求都是新的request，所以是线程安全的

用ThreadLocal也是线程安全的

springMVC @ResponseBody HandlerInterceptor ModelAndView null

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