13_SpringMVC_异常处理

不念不忘少年蓝@ 2023-09-27 13:27 127阅读 0赞

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

![ea1494ae1ebd86b1b5e17275061376a7.png][]

#### 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

此处优先级低于局部异常处理器

package com.msb.exceptionhandler;
    import org.springframework.web.bind.annotation.ControllerAdvice;
    import org.springframework.web.bind.annotation.ExceptionHandler;
    import org.springframework.web.servlet.ModelAndView;
    /**
     * @Author: Ma HaiYang
     * @Description: MircoMessage:Mark_7001
     */
    @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

xml配置

<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

/**
     * 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;
        }}

[ea1494ae1ebd86b1b5e17275061376a7.png]: https://img-blog.csdnimg.cn/img_convert/ea1494ae1ebd86b1b5e17275061376a7.png