springcloud gateway中进行统一处理api接口异常返回

柔情只为你懂 2021-05-12 11:49 1485阅读 0赞

我的项目中，使用spring cloud gateway作为路由，根据路由规则访问不同的api，api中使用的是fegin，当api未启动或者出现异常时候，会返回以下的异常信息  
![在这里插入图片描述][20200218135141278.png]  
而正常的情况我们接口返回的数据是经过封装的，所以我们需要将这里的异常也进行处理，使其数据格式与我们接口中保持一致，方便前端进行统一处理。  
获取及重新捕获异常的代码：

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.*;
    import java.util.HashMap;
    import java.util.Map;
    
    /**
     * @description: 捕获及处理异常
     * @Author: 
     * @Date: 2020/2/15 9:46
     */
    public class JsonExceptionHandler extends DefaultErrorWebExceptionHandler { 
        public JsonExceptionHandler(ErrorAttributes errorAttributes, ResourceProperties resourceProperties,
                                    ErrorProperties errorProperties, ApplicationContext applicationContext) { 
            super(errorAttributes, resourceProperties, errorProperties, applicationContext);
        }
    
        /**
         * 获取异常属性
         */
        @Override
        protected Map<String, Object> getErrorAttributes(ServerRequest request, boolean includeStackTrace) { 
            int code = 500;
            Throwable error = super.getError(request);
            if (error instanceof org.springframework.cloud.gateway.support.NotFoundException) { 
                code = 404;
            }
            return response(code, this.buildMessage(request, error));
        }
    
        /**
         * 指定响应处理方法为JSON处理的方法
         * @param errorAttributes
         */
        @Override
        protected RouterFunction<ServerResponse> getRoutingFunction(ErrorAttributes errorAttributes) { 
            return RouterFunctions.route(RequestPredicates.all(), this::renderErrorResponse);
        }
    
        /**
         * 根据code获取对应的HttpStatus
         * @param errorAttributes
         */
        @Override
        protected HttpStatus getHttpStatus(Map<String, Object> errorAttributes) { 
            int statusCode = (int) errorAttributes.get("code");
            return HttpStatus.valueOf(statusCode);
        }
    
        /**
         * 构建异常信息
         * @param request
         * @param ex
         * @return
         */
        private String buildMessage(ServerRequest request, Throwable ex) { 
            StringBuilder message = new StringBuilder("Failed to handle request [");
            message.append(request.methodName());
            message.append(" ");
            message.append(request.uri());
            message.append("]");
            if (ex != null) { 
                message.append(": ");
                message.append(ex.getMessage());
            }
            return message.toString();
        }
    
        /**
         * 构建返回的JSON数据格式
         * @param status        状态码
         * @param errorMessage  异常信息
         * @return
         */
        public static Map<String, Object> response(int status, String errorMessage) { 
            Map<String, Object> map = new HashMap<>(3);
            map.put("code", status);
            map.put("message", errorMessage);
            map.put("data", null);
            return map;
        }
    }

config类代码：

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;
    
    /**
     * @description: 异常的配置
     * @Author: 
     * @Date: 2020/2/15 9:44
     */
    @Configuration
    @EnableConfigurationProperties({ ServerProperties.class, ResourceProperties.class})
    public class ExceptionConfig { 
        private final ServerProperties serverProperties;
    
        private final ApplicationContext applicationContext;
    
        private final ResourceProperties resourceProperties;
    
        private final List<ViewResolver> viewResolvers;
    
        private final ServerCodecConfigurer serverCodecConfigurer;
    
        public ExceptionConfig(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) { 
            JsonExceptionHandler exceptionHandler = new JsonExceptionHandler(
                    errorAttributes,
                    this.resourceProperties,
                    this.serverProperties.getError(),
                    this.applicationContext);
            exceptionHandler.setViewResolvers(this.viewResolvers);
            exceptionHandler.setMessageWriters(this.serverCodecConfigurer.getWriters());
            exceptionHandler.setMessageReaders(this.serverCodecConfigurer.getReaders());
            return exceptionHandler;
        }
    }

pom文件中的内容：

<dependency>
       <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter</artifactId>
     </dependency>
    
     <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-actuator</artifactId>
     </dependency>
    
     <dependency>
          <groupId>org.springframework.boot</groupId>
          <artifactId>spring-boot-starter-webflux</artifactId>
     </dependency>
    
     <dependency>
         <groupId>org.springframework.cloud</groupId>
         <artifactId>spring-cloud-starter-gateway</artifactId>
     </dependency>

我这里的springboot版本是2.1.12RELEASE，springcloud版本是Greenwich.SR5。  
配置好之后，返回请求未启动的api服务时，返回截图：  
![在这里插入图片描述][20200218140205377.png]

[20200218135141278.png]: /images/20210511/c651af443b6e411a9d4a15a5c912dcce.png
[20200218140205377.png]: /images/20210511/12db3eee694445e4ab26395d67436f39.png