解决异常的初衷
最近在做一个项目的时候,出现异常的时候会直接暴露给页面,页面是一堆很不友好的代码,客户的第一反应就是“这是什么玩意?”,为了解决这个问题,借鉴并改进,通过创建全局异常处理类,返回一些有提示性的、有图的异常页面。
解决方案
一、主要是通过 @ControllerAdvice 的功能捕捉Cotroller层的异常,不仅通过页面转发还可以通过JSON的方式回显
建立请求拦截器 ExceptionInterceptor,拦截返回页面和Controller的请求,判断是JSON还是返回页面
@Component
public class ExceptionInterceptor implements HandlerInterceptor{
@Override
public boolean preHandle(HttpServletRequest req, HttpServletResponse resp, Object handler) throws Exception {
if (!(handler instanceof HandlerMethod)) {
return true;
}
HandlerMethod hm = (HandlerMethod) handler;
Method method = hm.getMethod();
boolean isPage = method.getReturnType().equals(String.class);
boolean isJosn = method.isAnnotationPresent(ResponseBody.class);
boolean isController = (!hm.getBeanType().isAnnotationPresent(RestController.class) && hm.getBeanType().isAnnotationPresent(Controller.class));
req.setAttribute(Constants.REPONSE_PAGE_TYPE, isPage && !isJosn && isController);
return false;
}
@Override
public void afterCompletion(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, Exception arg3)
throws Exception {
}
@Override
public void postHandle(HttpServletRequest arg0, HttpServletResponse arg1, Object arg2, ModelAndView arg3)
throws Exception {
}
}
二、处理异常结果,通过判断返回的是页面还是JSON数据来进行不同的处理通过http协议中不同的状态码进行分析,返回不同处理页面
@ControllerAdvice
public class GlobalExceptionResolver {
private static final Logger logger = LoggerFactory.getLogger(GlobalExceptionResolver.class);
@ExceptionHandler(Exception.class )
@ResponseBody
public ModelAndView handler(Exception e,HttpServletRequest request, HttpServletResponse response) throws Exception{
logger.error(e.getMessage(),e);
Object o = request.getAttribute(Constants.REPONSE_PAGE_TYPE);
if( o == null) {
throw e;
}
boolean isView = (Boolean)o;
if(isView){ //返回页面
//获取http状态码statusCode:401,404.jsp,500
Integer statusCode = (Integer) request.getAttribute("javax.servlet.error.status_code");
if(statusCode == 400){
return new ModelAndView("error/400");
}else if(statusCode == 403){
return new ModelAndView("error/403");
}else if(statusCode == 404){
return new ModelAndView("error/404");
}else{
return new ModelAndView("error/500");
}
}
//返回json
ModelAndView mv = new ModelAndView(new MappingJackson2JsonView());
mv.addObject("code","500");
mv.addObject("message",e.getMessage());
return mv;
}
}