在发生错误时服务器会自动重定向到error页面,为什么还需要定义一个新的类处理呢?
服务器只是在错误发生时跳转到错误页面,但是我们还需要记录日志,并且在异步请求中不是返回页面,而是返回json,这些都是服务器不会帮你做的事
代码示例
// 该类管理所有Controller类
@ControllerAdvice(annotations = Controller.class)
public class ExceptionAdvice {
private static final Logger logger = LoggerFactory.getLogger(Exception.class);
@ExceptionHandler({Exception.class})
public void handleException(Exception e, HttpServletRequest request, HttpServletResponse response) throws IOException {
logger.error("server is abnormal: " + e.getMessage());
for(StackTraceElement element : e.getStackTrace()){
logger.error(element.toString());
}
// 获取请求头中的“x-requested-with”字段的值,该字段用于标志请求是异步请求还是正常请求
// 如果字段的值是”XMLHttpRequest“,说明是异步请求
String xRequestedWith = request.getHeader("x-requested-with");
// If the request is asynchronous, the string is returned directly
if("XMLHttpRequest".equals(xRequestedWith)){
response.setContentType("application/plain;charset=utf-8");
PrintWriter writer = response.getWriter();
writer.write(CommunityUtil.getJSONString(1, "server is abnormal"));
}else{
response.sendRedirect(request.getContextPath() + "/error");
}
}
}