对于spring boot 项目 全局异常拦截可以使用 @RestControllerAdvice 和@ExceptionHandler(Exception.class) 注解 进行全局异常处理。对于Gateway 内部的异常处理需要使用如下方法

package config.exception;

import org.springframework.beans.factory.ObjectProvider;
import org.springframework.boot.autoconfigure.web.ResourceProperties;
import org.springframework.boot.autoconfigure.web.ServerProperties;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.boot.web.reactive.error.ErrorAttributes;
import org.springframework.boot.web.reactive.error.ErrorWebExceptionHandler;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.Ordered;
import org.springframework.core.annotation.Order;
import org.springframework.http.codec.ServerCodecConfigurer;
import org.springframework.web.reactive.result.view.ViewResolver;

import java.util.Collections;
import java.util.List;


@Configuration
@EnableConfigurationProperties({ServerProperties.class, ResourceProperties.class})
public class GatewayErrorConfiguration {
    private final ServerProperties serverProperties;

    private final ApplicationContext applicationContext;

    private final ResourceProperties resourceProperties;

    private final List<ViewResolver> viewResolvers;

    private final ServerCodecConfigurer serverCodecConfigurer;

    public GatewayErrorConfiguration(ServerProperties serverProperties,
                                     ResourceProperties resourceProperties,
                                     ObjectProvider<List<ViewResolver>> viewResolversProvider,
                                     ServerCodecConfigurer serverCodecConfigurer,
                                     ApplicationContext applicationContext) {
        this.serverProperties = serverProperties;
        this.applicationContext = applicationContext;
        this.resourceProperties = resourceProperties;
        this.viewResolvers = viewResolversProvider.getIfAvailable(Collections::emptyList);
        this.serverCodecConfigurer = serverCodecConfigurer;
    }

    @Bean
    @Order(Ordered.HIGHEST_PRECEDENCE)
    public ErrorWebExceptionHandler errorWebExceptionHandler(ErrorAttributes errorAttributes) {
        GatewayJsonExceptionHandler exceptionHandler = new GatewayJsonExceptionHandler(
                errorAttributes,
                this.resourceProperties,
                this.serverProperties.getError(),
                this.applicationContext);
        exceptionHandler.setViewResolvers(this.viewResolvers);
        exceptionHandler.setMessageWriters(this.serverCodecConfigurer.getWriters());
        exceptionHandler.setMessageReaders(this.serverCodecConfigurer.getReaders());
        return exceptionHandler;
    }

}

package config.exception;

import common.BaseException;
import org.springframework.boot.autoconfigure.web.ErrorProperties;
import org.springframework.boot.autoconfigure.web.ResourceProperties;
import org.springframework.boot.autoconfigure.web.reactive.error.DefaultErrorWebExceptionHandler;
import org.springframework.boot.web.reactive.error.ErrorAttributes;
import org.springframework.context.ApplicationContext;
import org.springframework.http.HttpStatus;
import org.springframework.web.reactive.function.server.RequestPredicates;
import org.springframework.web.reactive.function.server.RouterFunction;
import org.springframework.web.reactive.function.server.RouterFunctions;
import org.springframework.web.reactive.function.server.ServerRequest;
import org.springframework.web.reactive.function.server.ServerResponse;

import java.util.HashMap;
import java.util.Map;

public class GatewayJsonExceptionHandler extends DefaultErrorWebExceptionHandler {

    public GatewayJsonExceptionHandler(ErrorAttributes errorAttributes, ResourceProperties resourceProperties,
                                       ErrorProperties errorProperties, ApplicationContext applicationContext) {
        super(errorAttributes, resourceProperties, errorProperties, applicationContext);
    }


    @Override
    protected Map<String, Object> getErrorAttributes(ServerRequest request, boolean includeStackTrace) {
        int status = 500;
        String code = "";
        String errorMessage = "系统异常";
        Throwable error = super.getError(request);
         if (error instanceof BaseException) {
            status = 200;
            BaseException baseException = (BaseException) error;
            code = baseException.getCode();
            errorMessage = baseException.getMessage();
        }

        Map<String, Object> map = new HashMap<>();
        map.put("status", status);
        map.put("code", code);
        map.put("message", errorMessage);
        map.put("data", null);
        return map;
    }


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


//    @Override
//    protected RouterFunction<ServerResponse> getRoutingFunction(
//            ErrorAttributes errorAttributes) {
//        return RouterFunctions.route(acceptsTextHtml(), this::renderErrorView)
//                .andRoute(RequestPredicates.all(), this::renderErrorResponse);
//    }
    @Override
    protected HttpStatus getHttpStatus(Map<String, Object> errorAttributes) {
        return HttpStatus.valueOf((int)errorAttributes.get("status"));
    }
}