需要掌握：
https://www.malaoshi.top/show_1IX74ajxo0V5.html
说明
BasicExceptionController 功能非常强大，是SpringBoot默认处理异常方式，在没有配置任何异常处理时，当访问controlle抛出异常时，就是使用该方式处理异常的
也是SpringBoot 兜底 的处理异常方式，当 静态资源不存在时、过滤器抛错，都可以使用该方式处理异常
与 @ControllerAdvice、@RestControllerAdvice的区别
@ControllerAdvice、@RestControllerAdvice 只能处理 Controller 抛出的异常
当 过滤器抛错 ，该注解将无法处理
当 资源不存在时（404错误），使用该注解能处理，比较麻烦
应用场景
如果前端程序员，请求api时把接口地址写错了，就会得到一个404错误，如下：
{
"timestamp": 1492063521109,
"status": 404,
"error": "Not Found",
"message": "No message available",
"path": "/rest11/auth"
}
虽然也清晰明了，但与 统一的返回格式不一致
一般统一返回json格式如下：
{
"code": 404,
"msg": "Not Found"
}
源码
BasicExceptionController 实现 ErrorController 接口
BasicExceptionController 部分源码 如下：
// 必须有 @Controller
@Controller
// 默认路由是 /error，也就是说不能再有controller使用该路由
@RequestMapping("${server.error.path:${error.path:/error}}")
public class BasicErrorController extends AbstractErrorController {
// 浏览器发来请求，就执行该方法，返回 html 页面
@RequestMapping(produces = MediaType.TEXT_HTML_VALUE)
public ModelAndView errorHtml(HttpServletRequest request, HttpServletResponse response) {
HttpStatus status = getStatus(request);
Map<String, Object> model = Collections
.unmodifiableMap(getErrorAttributes(request, isIncludeStackTrace(request, MediaType.TEXT_HTML)));
response.setStatus(status.value());
ModelAndView modelAndView = resolveErrorView(request, response, status, model);
return (modelAndView != null) ? modelAndView : new ModelAndView("error", model);
}
// ajax、客户度发请求，就执行该方法，返回json字符串
@RequestMapping
public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) {
HttpStatus status = getStatus(request);
if (status == HttpStatus.NO_CONTENT) {
return new ResponseEntity<>(status);
}
Map<String, Object> body = getErrorAttributes(request, isIncludeStackTrace(request, MediaType.ALL));
return new ResponseEntity<>(body, status);
}
实现
静态资源不存在时、过滤器抛错，都可以使用该方式处理异常
package top.malaoshi.netdisk.config;
import org.springframework.boot.autoconfigure.web.ServerProperties;
import org.springframework.boot.autoconfigure.web.servlet.error.BasicErrorController;
import org.springframework.boot.web.servlet.error.DefaultErrorAttributes;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.ResponseEntity;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.servlet.ModelAndView;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.util.HashMap;
import java.util.Map;
@Controller
@RequestMapping({"${server.error.path:${error.path:/error}}"})
public class MyBasicErrorController extends BasicErrorController {
public MyBasicErrorController(ServerProperties serverProperties) {
super(new DefaultErrorAttributes(), serverProperties.getError());
}
@Override
public String getErrorPath() {
return null;
}
@RequestMapping(produces = MediaType.TEXT_HTML_VALUE)
public ModelAndView errorHtml(HttpServletRequest request, HttpServletResponse response) {
//请求的状态
HttpStatus status = getStatus(request);
response.setStatus(getStatus(request).value());
Map<String, Object> model = getErrorAttributes(request,isIncludeStackTrace(request, MediaType.TEXT_HTML));
ModelAndView modelAndView = resolveErrorView(request, response, status, model);
//指定自定义的视图
return (modelAndView == null ? new ModelAndView("error", model) : modelAndView);
}
@Override
public ResponseEntity<Map<String, Object>> error(HttpServletRequest request) {
HttpStatus status = getStatus(request);
Map<String, Object> map = new HashMap<String, Object>(16);
Map<String, Object> originalMsgMap = getErrorAttributes(request, isIncludeStackTrace(request, MediaType.ALL));
String path = (String)originalMsgMap.get("path");
String error = (String)originalMsgMap.get("error");
String message = (String)originalMsgMap.get("message");
String msg = null;
if(status.value() == 500){
msg = message;
}else{ // 如果404等异常，message是空的
msg = error;
}
map.put("code", status.value());
map.put("msg", msg);
return new ResponseEntity<Map<String, Object>>(map, status);
}
}
参考：
https://www.jianshu.com/p/ec932d6091c1
https://www.cnblogs.com/54chensongxia/p/14007696.html
https://blog.csdn.net/m1090760001/article/details/105454399
https://blog.csdn.net/java_chegnxuyuan/article/details/100941768