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
<context:component-scan base-package="com.msb.service,com.msb.exceptionhandler"/>
3使用：SimpleMappingExceptionResolver
全局范围有效,在SpringMVC.xml配置
<!--自定义异常解析器-->
<bean id="exceptionResolver" class="org.springframework.web.servlet.handler.SimpleMappingExceptionResolver">
<property name="exceptionMappings">
<props>
<prop key="java.lang.ArithmeticException">redirect:/error.jsp</prop>
<prop key="java.lang.NullPointerException">redirect:/error2.jsp</prop>
</props>
</property>
</bean>配置类配置
/**
* 全局异常
*/
@Configuration
public class GloableException2 {
@Bean
public 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
*/
@Configuration
public class GloableException3 implements HandlerExceptionResolver {
@Override
public 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;
}}
