13_SpringMVC_异常处理

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 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

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
 

<!--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

/**
 * 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;
    }}

 

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