SpringBoot全局异常处理与定制404页面的方法

@Controller
@RequestMapping({"${server.error.path:${error.path:/error}}"})
public class BasicErrorController extends AbstractErrorController {

 	/**
 	 * 错误的页面响应 
 	 */
 @RequestMapping(produces = {"text/html"})
 public ModelAndView errorHtml(HttpServletRequest request, HttpServletResponse response) {
 HttpStatus status = this.getStatus(request);
 Map<String, Object> model = Collections.unmodifiableMap(this.getErrorAttributes(request, this.isIncludeStackTrace(request, MediaType.TEXT_HTML)));
 response.setStatus(status.value());
 	// 得到一个modelAndView对象
 ModelAndView modelAndView = this.resolveErrorView(request, response, status, model);
 return modelAndView != null ? modelAndView : new ModelAndView("error", model);
 }
		
 /**
 * 错误的json响应
 */
 @RequestMapping
 public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) {
 HttpStatus status = this.getStatus(request);
 if (status == HttpStatus.NO_CONTENT) {
  return new ResponseEntity(status);
 } else {
  Map<String, Object> body = this.getErrorAttributes(request, this.isIncludeStackTrace(request, MediaType.ALL));
  return new ResponseEntity(body, status);
 }
 }

@RequestMapping("haserror")
@ResponseBody
public Object myError(){
 int i =10/0;
 return "something is error";
}
这是一个错误页面：
<ul>
 <li>错误状态码：[[${status}]]</li>
 <li>错误消息：[[${error}]]</li>
 <li>异常对象：[[${exception}]]</li>
 <li>异常消息：[[${message}]]</li>
 <li>当前时间：[[${timestamp}]]</li>
</ul>

{
"timestamp": "2020-04-22T16:13:37.506+0000",
"status": 500,
"error": "Internal Server Error",
"message": "/ by zero",
"path": "/hello/haserror",
"reason": "完了，你写的代码又产生了一次线上事故"
}

@Component
public class MyErrorAttributes extends DefaultErrorAttributes {
 @Override
 public Map<String, Object> getErrorAttributes(WebRequest webRequest, boolean includeStackTrace) {
 //调用父类的方法，会自动获取内置的那些属性，如果你不想要，可以不调用这个
 Map<String, Object> errorAttributes = super.getErrorAttributes(webRequest, includeStackTrace);

 //添加自定义的属性
 errorAttributes.put("reason","完了，你写的代码又产生了一次线上事故");
 // 你可以看一下这个方法的参数webRequest这个对象，我相信你肯定能发现好东西

 return errorAttributes;
 }
}

@ControllerAdvice
public class ErrroAcvice {

 /**
 * 全局捕获异常的切面类
 * @param request 请求对象，可不传
 * @param response 响应对象，可不传
 * @param e 异常类(这个要和你当前捕获的异常类是同一个)
 */
 @ExceptionHandler(Exception.class) //也可以只对一个类进行捕获
 public void errorHandler(HttpServletRequest request, HttpServletResponse response,Exception e){
 	/*
 	 * You can do everything you want to do
  * 这里你拿到了request和response对象，你可以做任何你想做的事
  * 比如：
  *	1.用request从头信息中拿到Accept来判断是请求方可接收的类型从而进行第一个方法的判断
  *	2.如果你也想返回一个页面，使用response对象进行重定向到自己的错误页面就可以了
  * 3.你甚至还拿到了异常对象
 	 */
 
 String accept = request.getHeader("Accept");
				// 根据这个字符串来判断做出什么响应	
 
 try {
  response.setStatus(500);
  response.getWriter().write("hello");
 } catch (IOException ex) {
  ex.printStackTrace();
 }
 
 }
}