SpringBoot自定义错误处理逻辑详解

  <h2 th:text="${status}">page not found</h2>
  <h3 th:text="${#message}">We Couldn't Find This Page</h3>

	<h3 th:text="${message}">Something went wrong.</h3>
	<p class="nrml-txt" th:text="${trace}">Why not try refreshing you page? Or you can <a href="#" rel="external nofollow" >contact our support</a> if the problem persists.</p>

package com.wanqing.admin.exception;
import lombok.extern.slf4j.Slf4j;
import org.springframework.web.bind.annotation.ControllerAdvice;
import org.springframework.web.bind.annotation.ExceptionHandler;
@Slf4j
@ControllerAdvice // 使用此注释
public class GlobalExceptionHandler {
    @ExceptionHandler({ArithmeticException.class, NullPointerException.class
    }) // 使用此注释，大括号内为可以处理的异常信息
    public String handleArithException(Exception e){
        log.info("异常是：" + e);
        return "login"; // 返回一个视图地址（ModelAndView）
    }
}

import org.springframework.http.HttpStatus;
import org.springframework.web.bind.annotation.ResponseStatus;
@ResponseStatus(value = HttpStatus.FORBIDDEN, reason = "用户数量太多~~") // 异常可以返回状态码信息
public class userToMany extends  RuntimeException{
    // 有参构造器
    public userToMany(String message){
        super(message);
    }
    public userToMany(){
    }
}

    protected ModelAndView applyStatusAndReason(int statusCode, @Nullable String reason, HttpServletResponse response) throws IOException {
        if (!StringUtils.hasLength(reason)) {
            response.sendError(statusCode);
        } else {
            String resolvedReason = this.messageSource != null ? this.messageSource.getMessage(reason, (Object[])null, reason, LocaleContextHolder.getLocale()) : reason;
            response.sendError(statusCode, resolvedReason);
        }
        return new ModelAndView();
    }

    protected ModelAndView doResolveException(HttpServletRequest request, HttpServletResponse response, @Nullable Object handler, Exception ex) {
        try {
            if (ex instanceof HttpRequestMethodNotSupportedException) {
                return this.handleHttpRequestMethodNotSupported((HttpRequestMethodNotSupportedException)ex, request, response, handler);
            }
			// 此处省略.............
            if (ex instanceof HttpMessageNotWritableException) {
                return this.handleHttpMessageNotWritable((HttpMessageNotWritableException)ex, request, response, handler);
            }
            if (ex instanceof MethodArgumentNotValidException) {
                return this.handleMethodArgumentNotValidException((MethodArgumentNotValidException)ex, request, response, handler);
            }
        } catch (Exception var6) {
            if (this.logger.isWarnEnabled()) {
                this.logger.warn("Failure while trying to resolve exception [" + ex.getClass().getName() + "]", var6);
            }
        }
        return null;
    }

import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
@Order(value = Ordered.HIGHEST_PRECEDENCE) // 优先级数字越小，优先级越高
@Component // 注册到容器中
public class CustomerHandlerResolver implements HandlerExceptionResolver {
    @Override
    public ModelAndView resolveException(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse, Object o, Exception e) {
        try {
            httpServletResponse.sendError(511, "我不喜欢的错误");
        } catch (IOException e1){
            e1.printStackTrace();
        }
        return new ModelAndView();
    }
}