自定义异常处理器

import org.springframework.boot.autoconfigure.web.WebProperties;
import org.springframework.boot.autoconfigure.web.reactive.error.AbstractErrorWebExceptionHandler;
import org.springframework.boot.web.error.ErrorAttributeOptions;
import org.springframework.boot.web.reactive.error.ErrorAttributes;
import org.springframework.context.ApplicationContext;
import org.springframework.core.annotation.Order;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.codec.ServerCodecConfigurer;
import org.springframework.stereotype.Component;
import org.springframework.web.reactive.function.BodyInserters;
import org.springframework.web.reactive.function.server.*;
import reactor.core.publisher.Mono;

import java.util.Map;
@Component
@Order(-1)
public class CustomException extends AbstractErrorWebExceptionHandler {

    public CustomException(ErrorAttributes errorAttributes,
                           ApplicationContext applicationContext,
                           ServerCodecConfigurer serverCodecConfigurer) {
        super(errorAttributes, new WebProperties().getResources(), applicationContext);
        super.setMessageWriters(serverCodecConfigurer.getWriters());
        super.setMessageReaders(serverCodecConfigurer.getReaders());
    }

    @Override
    protected RouterFunction<ServerResponse> getRoutingFunction(ErrorAttributes errorAttributes) {
        return RouterFunctions.route(RequestPredicates.all(), this::readerErrorResponse);
    }


    private Mono<ServerResponse> readerErrorResponse(ServerRequest serverRequest) {
        //获取异常信息
        Map<String, Object> map = getErrorAttributes(serverRequest, ErrorAttributeOptions.defaults());
        return ServerResponse.status(HttpStatus.NOT_FOUND) //404
                .contentType(MediaType.APPLICATION_JSON)   //JSON
                .body(BodyInserters.fromValue(map));       //响应体
    }

}

自定义错误内容

import org.springframework.boot.web.error.ErrorAttributeOptions;
import org.springframework.boot.web.reactive.error.DefaultErrorAttributes;
import org.springframework.stereotype.Component;
import org.springframework.web.reactive.function.server.ServerRequest;

import java.util.Map;

@Component
public class CustomException2 extends DefaultErrorAttributes {

    @Override
    public Map<String, Object> getErrorAttributes(ServerRequest request, ErrorAttributeOptions options) {
        // super.getErrorAttributes(request, options); 这里可以不用get ，直接new 一个 hashMap 也可以
        Map<String, Object> resError = super.getErrorAttributes(request, options);
        resError.put("message", "请求条件不满足");

        return resError;
    }

}