myBatis自定义异常处理器

- 日理万妓 2022-06-02 10:10 262阅读 0赞

## 1: 异常处理思 ##

##    系统中异常包括两类：预期异常和运行时异常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出现异常都通过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，下面是我从网上找到的一张图, ##

![SouthEast][]

####       一般处理异常时,通常是通过日志记录异常信息,然后通知维护人员,最后给出用户提示,如网络电缆没有插好等等...... ####

####       自定义异常类 ####

public class CustomException extends Exception {
    
        private String message; //  异常信息
    
        //提供有参构造
        public CustomException(String msg){
            this.message = msg;
        }
    
        @Override
        public String getMessage() {
            return message;
        }
    
        public void setMessage(String message) {
            this.message = message;
        }
    }

##### 定义异常处理类 #####

import org.slf4j.Logger;
    import org.slf4j.LoggerFactory;
    import org.springf
    ramework.web.servlet.HandlerExceptionResolver;
    import org.springframework.web.servlet.ModelAndView;
    
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    import java.io.PrintWriter;
    import java.io.StringWriter;
    
    public class CustomExceptionResolver implements HandlerExceptionResolver {
    
        private Logger log = LoggerFactory.getLogger(CustomExceptionResolver.class);
        @Override
        public ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object handler, Exception exception) {
            String message;
            if(exception instanceof CustomException){
                //是预期异常
                CustomException ex = (CustomException) exception;
    
                //获取我们自定义的异常信息
                message = ex.getMessage();
    
            } else {
                //运行时异常   友好提示....
                message = "网络电缆有问题,请稍后再试..........";
    
                //异常信息打印到日志
    
    //            exception.getMessage();
    
                StringWriter s = new StringWriter();
                PrintWriter printWriter = new PrintWriter(s);
                exception.printStackTrace(printWriter);
                s.toString();
    
                log.error(s.toString());
                //发送异常信息,省略
    //            xxxxx
            }
    
    
            //跳转错误页面
            ModelAndView mView = new ModelAndView();
            mView.addObject("message",message); //设置错误消息
            mView.setViewName("error");//跳转错误页面,使用了视图视图解析器,这是逻辑路径
    
            return mView;
    
        }
    }

#### 异常处理器配置 ####

springMvc 配置文件里需要配置配置

<bean id="handlerExceptionResolver" class="cn.csdn.controller.exectionResolver.CustomExceptionResolver"/>

[SouthEast]: /images/20220602/bf7f218ba9844c1e876d20f9db713593.png