SpringMVC异常简介
系统中异常包括两类：预期异常(检查型异常)和运行时异常 RuntimeException，前者通过捕获异常从而获取异常信息， 后者主要通过规范代码开发、测试通过手段减少运行时异常的发生。
系统的 dao、service、controller 出现都通过 throws Exception 向上抛出，最后由 springmvc 前端控制器交由异常处理器进行异常处理，如下图

异常处理具体实现

1使用@ExceptionHandler注解处理异常

缺点：只能处理当前Controller中的异常。

@Controller
public class ControllerDemo1 {@RequestMapping("test1.action")public String test1(){int i = 1/0;return "success.jsp";}@RequestMapping("test2.action")public String test2(){String s =null;System.out.println(s.length());return "success.jsp";}@ExceptionHandler(value ={ArithmeticException.class,NullPointerException.class} )public ModelAndView handelException(){ModelAndView mv =new ModelAndView();mv.setViewName("error1.jsp");return mv;}
}

2使用：@ControllerAdvice+@ExceptionHandler

全局使用,此处优先级低于局部异常处理器

@ControllerAdvice
public class GloableExceptionHandler1 {@ExceptionHandler(value ={ArithmeticException.class,NullPointerException.class} )public ModelAndView handelException(){ModelAndView mv =new ModelAndView();mv.setViewName("error1.jsp");return mv;}
}

配置包扫描

3使用：SimpleMappingExceptionResolver

 
全局范围有效,在SpringMVC.xml配置

redirect:/error.jspredirect:/error2.jsp

配置类配置

/*** 全局异常*/@Configurationpublic class GloableException2 {@Beanpublic SimpleMappingExceptionResolver getSimpleMappingExceptionResolver(){SimpleMappingExceptionResolver resolver = new SimpleMappingExceptionResolver();Properties prop = new Properties();prop.put("java.lang.NullPointerException","error1.jsp");prop.put("java.lang.ArithmeticException","error2.jsp");resolver.setExceptionMappings(prop);return resolver;}
}

4自定义的HandlerExceptionResolver

0xml配置,使用配置类代替配置文件,作用范围同方式三一样

/*** 全局异常* HandlerExceptionResolve*/@Configurationpublic class GloableException3 implements HandlerExceptionResolver {@Overridepublic ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) {ModelAndView mv = new ModelAndView();if(e instanceof NullPointerException){mv.setViewName("error1");}if(e instanceof ArithmeticException){mv.setViewName("error2");}mv.addObject("msg",e);return mv;}}