Spring Cloud Gateway-自定义异常处理

Dlwyz

已于 2025-01-20 17:16:15 修改

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文章标签： gateway

于 2025-01-03 16:15:44 首次发布

本文链接：https://blog.youkuaiyun.com/MyNote1994/article/details/144910691

参考 https://blog.youkuaiyun.com/suyuaidan/article/details/132663141，写法不同于注入方式不一样

ErrorWebFluxAutoConfiguration

@Configuration(proxyBeanMethods = false)
@ConditionalOnWebApplication(type = ConditionalOnWebApplication.Type.REACTIVE)
@ConditionalOnClass(WebFluxConfigurer.class)
@AutoConfigureBefore(WebFluxAutoConfiguration.class)
@EnableConfigurationProperties({ ServerProperties.class, ResourceProperties.class })
public class ErrorWebFluxAutoConfiguration {

	private final ServerProperties serverProperties;

	public ErrorWebFluxAutoConfiguration(ServerProperties serverProperties) {
		this.serverProperties = serverProperties;
	}

	@Bean
	@ConditionalOnMissingBean(value = ErrorWebExceptionHandler.class, search = SearchStrategy.CURRENT)
	@Order(-1)
	public ErrorWebExceptionHandler errorWebExceptionHandler(ErrorAttributes errorAttributes,
			ResourceProperties resourceProperties, ObjectProvider<ViewResolver> viewResolvers,
			ServerCodecConfigurer serverCodecConfigurer, ApplicationContext applicationContext) {
		DefaultErrorWebExceptionHandler exceptionHandler = new DefaultErrorWebExceptionHandler(errorAttributes,
				resourceProperties, this.serverProperties.getError(), applicationContext);
		exceptionHandler.setViewResolvers(viewResolvers.orderedStream().collect(Collectors.toList()));
		exceptionHandler.setMessageWriters(serverCodecConfigurer.getWriters());
		exceptionHandler.setMessageReaders(serverCodecConfigurer.getReaders());
		return exceptionHandler;
	}

	@Bean
	@ConditionalOnMissingBean(value = ErrorAttributes.class, search = SearchStrategy.CURRENT)
	public DefaultErrorAttributes errorAttributes() {
		return new DefaultErrorAttributes();
	}

}

DefaultErrorWebExceptionHandler

public class DefaultErrorWebExceptionHandler extends AbstractErrorWebExceptionHandler {

	private static final MediaType TEXT_HTML_UTF8 = new MediaType("text", "html", StandardCharsets.UTF_8);

	private static final Map<HttpStatus.Series, String> SERIES_VIEWS;

	static {
		Map<HttpStatus.Series, String> views = new EnumMap<>(HttpStatus.Series.class);
		views.put(HttpStatus.Series.CLIENT_ERROR, "4xx");
		views.put(HttpStatus.Series.SERVER_ERROR, "5xx");
		SERIES_VIEWS = Collections.unmodifiableMap(views);
	}

	private final ErrorProperties errorProperties;

	/**
	 * Create a new {@code DefaultErrorWebExceptionHandler} instance.
	 * @param errorAttributes the error attributes
	 * @param resourceProperties the resources configuration properties
	 * @param errorProperties the error configuration properties
	 * @param applicationContext the current application context
	 */
	public DefaultErrorWebExceptionHandler(ErrorAttributes errorAttributes, ResourceProperties resourceProperties,
			ErrorProperties errorProperties, ApplicationContext applicationContext) {
		super(errorAttributes, resourceProperties, applicationContext);
		this.errorProperties = errorProperties;
	}

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

	/**
	 * Render the error information as an HTML view.
	 * @param request the current request
	 * @return a {@code Publisher} of the HTTP response
	 */
	protected Mono<ServerResponse> renderErrorView(ServerRequest request) {
		Map<String, Object> error = getErrorAttributes(request, getErrorAttributeOptions(request, MediaType.TEXT_HTML));
		int errorStatus = getHttpStatus(error);
		ServerResponse.BodyBuilder responseBody = ServerResponse.status(errorStatus).contentType(TEXT_HTML_UTF8);
		return Flux.just(getData(errorStatus).toArray(new String[] {}))
				.flatMap((viewName) -> renderErrorView(viewName, responseBody, error))
				.switchIfEmpty(this.errorProperties.getWhitelabel().isEnabled()
						? renderDefaultErrorView(responseBody, error) : Mono.error(getError(request)))
				.next();
	}

	private List<String> getData(int errorStatus) {
		List<String> data = new ArrayList<>();
		data.add("error/" + errorStatus);
		HttpStatus.Series series = HttpStatus.Series.resolve(errorStatus);
		if (series != null) {
			data.add("error/" + SERIES_VIEWS.get(series));
		}
		data.add("error/error");
		return data;
	}

	/**
	 * Render the error information as a JSON payload.
	 * @param request the current request
	 * @return a {@code Publisher} of the HTTP response
	 */
	protected Mono<ServerResponse> renderErrorResponse(ServerRequest request) {
		Map<String, Object> error = getErrorAttributes(request, getErrorAttributeOptions(request, MediaType.ALL));
		return ServerResponse.status(getHttpStatus(error)).contentType(MediaType.APPLICATION_JSON)
				.body(BodyInserters.fromValue(error));
	}

	protected ErrorAttributeOptions getErrorAttributeOptions(ServerRequest request, MediaType mediaType) {
		ErrorAttributeOptions options = ErrorAttributeOptions.defaults();
		if (this.errorProperties.isIncludeException()) {
			options = options.including(Include.EXCEPTION);
		}
		if (isIncludeStackTrace(request, mediaType)) {
			options = options.including(Include.STACK_TRACE);
		}
		if (isIncludeMessage(request, mediaType)) {
			options = options.including(Include.MESSAGE);
		}
		if (isIncludeBindingErrors(request, mediaType)) {
			options = options.including(Include.BINDING_ERRORS);
		}
		return options;
	}

	/**
	 * Determine if the stacktrace attribute should be included.
	 * @param request the source request
	 * @param produces the media type produced (or {@code MediaType.ALL})
	 * @return if the stacktrace attribute should be included
	 */
	@SuppressWarnings("deprecation")
	protected boolean isIncludeStackTrace(ServerRequest request, MediaType produces) {
		switch (this.errorProperties.getIncludeStacktrace()) {
		case ALWAYS:
			return true;
		case ON_PARAM:
		case ON_TRACE_PARAM:
			return isTraceEnabled(request);
		default:
			return false;
		}
	}

	/**
	 * Determine if the message attribute should be included.
	 * @param request the source request
	 * @param produces the media type produced (or {@code MediaType.ALL})
	 * @return if the message attribute should be included
	 */
	protected boolean isIncludeMessage(ServerRequest request, MediaType produces) {
		switch (this.errorProperties.getIncludeMessage()) {
		case ALWAYS:
			return true;
		case ON_PARAM:
			return isMessageEnabled(request);
		default:
			return false;
		}
	}

	/**
	 * Determine if the errors attribute should be included.
	 * @param request the source request
	 * @param produces the media type produced (or {@code MediaType.ALL})
	 * @return if the errors attribute should be included
	 */
	protected boolean isIncludeBindingErrors(ServerRequest request, MediaType produces) {
		switch (this.errorProperties.getIncludeBindingErrors()) {
		case ALWAYS:
			return true;
		case ON_PARAM:
			return isBindingErrorsEnabled(request);
		default:
			return false;
		}
	}

	/**
	 * Get the HTTP error status information from the error map.
	 * @param errorAttributes the current error information
	 * @return the error HTTP status
	 */
	protected int getHttpStatus(Map<String, Object> errorAttributes) {
		return (int) errorAttributes.get("status");
	}

	/**
	 * Predicate that checks whether the current request explicitly support
	 * {@code "text/html"} media type.
	 * <p>
	 * The "match-all" media type is not considered here.
	 * @return the request predicate
	 */
	protected RequestPredicate acceptsTextHtml() {
		return (serverRequest) -> {
			try {
				List<MediaType> acceptedMediaTypes = serverRequest.headers().accept();
				acceptedMediaTypes.removeIf(MediaType.ALL::equalsTypeAndSubtype);
				MediaType.sortBySpecificityAndQuality(acceptedMediaTypes);
				return acceptedMediaTypes.stream().anyMatch(MediaType.TEXT_HTML::isCompatibleWith);
			}
			catch (InvalidMediaTypeException ex) {
				return false;
			}
		};
	}

}

观察上面的代码，我们可以知道我们要做两步工作

全局处理异常怎么操作（实现ErrorWebExceptionHandler，或者直接继承他的子类DefaultErrorWebExceptionHandler）
如何把异常处理注入到框架中（自定CustomErrorWebFluxAutoConfiguration）

自定义ErrorWebExceptionHandler

import lombok.extern.slf4j.Slf4j;
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.http.MediaType;
import org.springframework.web.reactive.function.BodyInserters;
import org.springframework.web.reactive.function.server.*;
import reactor.core.publisher.Mono;

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

/**
 * 自定义异常处理器
 */
@Slf4j
public class CustomErrorWebExceptionHandler extends DefaultErrorWebExceptionHandler {
    public CustomErrorWebExceptionHandler(ErrorAttributes errorAttributes, ResourceProperties resourceProperties,
                                          ErrorProperties errorProperties, ApplicationContext applicationContext) {
        super(errorAttributes, resourceProperties, errorProperties, applicationContext);
    }

    @Override
    protected Mono<ServerResponse> renderErrorResponse(ServerRequest request) {
        // 原始的异常信息可以用getError方法取得
        Throwable throwable = getError(request);
        // 这里和父类的做法一样，取得DefaultErrorAttributes整理出来的所有异常信息
        Map<String, Object> errorAttributes = getErrorAttributes(request, getErrorAttributeOptions(request, MediaType.ALL));
        HttpStatus status = HttpStatus.valueOf((Integer) errorAttributes.get("status"));

        // todo 写你自己的逻辑也可根据status封装不同的结果集枚举
        Map<String, Object> responseBodyMap = new HashMap<>();
        responseBodyMap.put("code", "my error code");
        responseBodyMap.put("msg", throwable.getMessage());
        return ServerResponse
                // http返回码
                .status(HttpStatus.INTERNAL_SERVER_ERROR)
                // 类型和以前一样
                .contentType(MediaType.APPLICATION_JSON)
                // 响应body的内容
                .body(BodyInserters.fromValue(responseBodyMap));
    }


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

}

自定义CustomErrorWebFluxAutoConfiguration

import com.hatzi.gateway.plus.handler.CustomErrorWebExceptionHandler;
import org.springframework.beans.factory.ObjectProvider;
import org.springframework.boot.autoconfigure.AutoConfigureBefore;
import org.springframework.boot.autoconfigure.condition.ConditionalOnClass;
import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
import org.springframework.boot.autoconfigure.condition.ConditionalOnWebApplication;
import org.springframework.boot.autoconfigure.condition.SearchStrategy;
import org.springframework.boot.autoconfigure.web.ResourceProperties;
import org.springframework.boot.autoconfigure.web.ServerProperties;
import org.springframework.boot.autoconfigure.web.reactive.WebFluxAutoConfiguration;
import org.springframework.boot.context.properties.EnableConfigurationProperties;
import org.springframework.boot.web.reactive.error.DefaultErrorAttributes;
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.config.WebFluxConfigurer;
import org.springframework.web.reactive.result.view.ViewResolver;

import java.util.List;
import java.util.stream.Collectors;

/**
 * @Description
 * @Author weiwenbin
 * @Date 2024/6/6 15:01
 */
@Configuration
@ConditionalOnWebApplication(type = ConditionalOnWebApplication.Type.REACTIVE)
@ConditionalOnClass(WebFluxConfigurer.class)
@AutoConfigureBefore(WebFluxAutoConfiguration.class)
@EnableConfigurationProperties({ServerProperties.class, ResourceProperties.class})
public class CustomErrorWebFluxAutoConfiguration {

    private final ServerProperties serverProperties;

    private final ApplicationContext applicationContext;

    private final ResourceProperties resourceProperties;

    private final List<ViewResolver> viewResolvers;

    private final ServerCodecConfigurer serverCodecConfigurer;

    public CustomErrorWebFluxAutoConfiguration(ServerProperties serverProperties,
                                               ResourceProperties resourceProperties,
                                               ObjectProvider<ViewResolver> viewResolversProvider,
                                               ServerCodecConfigurer serverCodecConfigurer,
                                               ApplicationContext applicationContext) {
        this.serverProperties = serverProperties;
        this.applicationContext = applicationContext;
        this.resourceProperties = resourceProperties;
        this.viewResolvers = viewResolversProvider.orderedStream()
                .collect(Collectors.toList());
        this.serverCodecConfigurer = serverCodecConfigurer;
    }

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

  @Bean
    @ConditionalOnMissingBean(value = ErrorAttributes.class, search = SearchStrategy.CURRENT)
    public DefaultErrorAttributes errorAttributes() {
        return new DefaultErrorAttributes();
    }
}