应用场景：当浏览器向浏览器发送申请，而服务器解决申请呈现了异样的状况，如果间接把错误信息给浏览器展现进去是很不好的，因为用户就能看到具体的代码错误信息。所以当出现异常状况时，服务器能够给用户一个本次申请异样的页面，让用户晓得以后服务器有点问题，请稍后再试。

实现流程

  • 1）自定义异样类
public class MyException  extends RuntimeException{     private String message;     public MyException(){}     public MyException(String message){        this.message = message;     }     public void setMessage(String message) {        this.message = message;     }     @Override     public String getMessage() {        return message;     }}

  • 2）自定义异样解决类，解决咱们抛出的异样

    • 对于异样的解决，我是把它转发到一个error页面，这里大家能够本人创立一个
@Componentpublic class ExceptionResolver implements HandlerExceptionResolver {     @Override     public ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) {        if (e instanceof MyException){                    ModelAndView mv = new ModelAndView();         mv.addObject("errorMessage", e.getMessage());         mv.setViewName("error.jsp");         return mv;        }        return null;     }}
  • Controller类：这里是捕捉了一个空指针异样，而后抛出了咱们自定义的异样
@Controllerpublic class UserController {     @RequestMapping("testException.do")     public String testException(){     try {            String str = null;            str.length();     }catch (NullPointerException e){            e.printStackTrace();            throw new MyException("服务器忙碌，请稍后再试！！！");     }            return "testException.jsp";     }}
  • ApplicationContext.xml（Spring外围配置文件）配置信息如下：
<?xml version="1.0" encoding="UTF-8"?><beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:context="http://www.springframework.org/schema/context" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:mvc="http://www.springframework.org/schema/mvc" xsi:schemaLocation="http://www.springframework.org/schema/beans https://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd"><!-- 开启spring注解驱动--> <context:component-scan base-package="com.cjh"/><!-- 开启mvc注解驱动--> <mvc:annotation-driven></mvc:annotation-driven></beans>