关于Spring框架中异常处理情况浅析

@Component
public class ExceptionResolver implements HandlerExceptionResolver {

    @Override
    public ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) {

        System.out.println("异常处理器正在执行中");

        ModelAndView mv = new ModelAndView();
        if (e instanceof NullPointerException){
            mv.addObject("msg","空指针异常");
        }else if (e instanceof AccessDeniedException){
            mv.addObject("msg","没有访问权限");

            System.out.println("111---222---333");
        }

        mv.setViewName("/error.html");
        return mv;
    }

}

<bean class="com.itheima.exception.MyExceptionResolver"></bean>

//声明该类是一个Controller的通知类，声明后该类就会被加载成异常处理器
@ControllerAdvice
public class ExceptionAdvice {

    //类中定义的方法携带@ExceptionHandler注解的会被作为异常处理器，后面添加实际处理的异常类型
    @ExceptionHandler(NullPointerException.class)
    @ResponseBody
    public String doNullException(Exception ex) {
        return "空指针异常";
    }
	//算术异常
    @ExceptionHandler(ArithmeticException.class)
    @ResponseBody
    public String doArithmeticException(Exception ex) {
        return "ArithmeticException";
    }

    @ExceptionHandler(Exception.class)
    @ResponseBody
    public String doException(Exception ex) {
        return "all";
    }
}