SpringMVC统一异常处理实例代码

public class CustomException extends Exception {
  
  //异常信息
  private String message;
  
  public CustomException(String message){
    super(message);
    this.message = message;
    
  }
  public String getMessage() {
    return message;
  }

  public void setMessage(String message) {
    this.message = message;
  }
  
}

public class CustomExceptionResolver implements HandlerExceptionResolver {

  //前端控制器DispatcherServlet在进行HandlerMapping、调用HandlerAdapter执行Handler过程中，如果遇到异常就会执行此方法
  //handler最终要执行的Handler，它的真实身份是HandlerMethod
  //Exception ex就是接收到异常信息
  @Override
  public ModelAndView resolveException(HttpServletRequest request,
      HttpServletResponse response, Object handler, Exception ex) {
    //输出异常
    ex.printStackTrace();
    
    //统一异常处理代码
    //针对系统自定义的CustomException异常，就可以直接从异常类中获取异常信息，将异常处理在错误页面展示
    //异常信息
    String message = null;
    CustomException customException = null;
    //如果ex是系统 自定义的异常，直接取出异常信息
    if(ex instanceof CustomException){
      customException = (CustomException)ex;
    }else{
      //针对非CustomException异常，对这类重新构造成一个CustomException，异常信息为“未知错误”
      customException = new CustomException("未知错误");
    }
    
    //错误 信息
    message = customException.getMessage();
    
    request.setAttribute("message", message);

    
    try {
      //转向到错误 页面
      request.getRequestDispatcher("/WEB-INF/jsp/error.jsp").forward(request, response);
    } catch (ServletException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
    
    return new ModelAndView();
  }

}

<!-- 定义统一异常处理器 -->
  <bean class="com.hao.ssm.exception.CustomExceptionResolver"></bean>