openFeign FallbackFactory无效

Question

问题：
我为远程调用配置了一个openFeign FallbackFactory，但是当远程服务异常并返回500时它不起作用。

报错信息
response:

{
  "timestamp": "2024-12-31T08:44:53.131+00:00",
  "status": 500,
  "error": "Internal Server Error",
  "path": "/demo/port"
}

控制台报错信息：
2024-12-31T16:44:53.129+08:00 ERROR 68881 --- [material-audience] [nio-7941-exec-4] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed: feign.FeignException$InternalServerError: [500] during [GET] to [http://material-tsp/health/port\] [DemoClient#port()]: [{"timestamp":"2024-12-31T08:44:53.125+00:00","status":500,"error":"Internal Server Error","path":"/health/port"}]] with root cause

feign.FeignException$InternalServerError: [500] during [GET] to [http://material-tsp/health/port\] [DemoClient#port()]: [{"timestamp":"2024-12-31T08:44:53.125+00:00","status":500,"error":"Internal Server Error","path":"/health/port"}] at feign.FeignException.serverErrorStatus(FeignException.java:259) ~[feign-core-13.3.jar:na] at feign.FeignException.errorStatus(FeignException.java:206) ~[feign-core-13.3.jar:na]

系统配置
pom.xml

<parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.3.3</version>
    </parent>

    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-dependencies</artifactId>
        <version>2023.0.3</version>
        <type>pom</type>
        <scope>import</scope>
    </dependency>

    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-openfeign</artifactId>
    </dependency>

DemoClient:

package com.link.code.materialaudience.openfeign;

import com.link.code.materialaudience.openfeign.fallback.RemoteDemoFallbackFactory;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;

@FeignClient(value = "material-tsp",fallbackFactory = RemoteDemoFallbackFactory.class)
public interface DemoClient {

    @GetMapping("health/port")
    String port();
}

RemoteDemoFallbackFactory：

package com.link.code.materialaudience.openfeign.fallback;

import com.link.code.materialaudience.openfeign.DemoClient;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.openfeign.FallbackFactory;
import org.springframework.stereotype.Component;

@Slf4j
@Component
public class RemoteDemoFallbackFactory implements FallbackFactory<DemoClient> {
    @Override
    public DemoClient create(Throwable cause) {
        return new DemoClient() {
            @Override
            public String port() {
                log.info("invoke service fail:{},",cause.toString(),cause);
                return "exception---null";
            }
        };
    }
}

Answer 1

上午好☀️☀️☀️️
本答案参考通义千问

当你遇到 OpenFeign 的 FallbackFactory 在处理 500 Internal Server Error 时无效的问题时，可以按照以下步骤进行排查和解决。

排查步骤

1. 检查依赖版本：

   • 确保 spring-cloud-dependencies 和 spring-cloud-starter-openfeign 的版本兼容。

2. 确保 FallbackFactory 实现正确：

   • 确认 FallbackFactory 实现类的注解和方法签名是否正确。

3. 检查配置文件：

   • 确保 application.yml 或 application.properties 文件中已经启用了 Feign 客户端。

4. 日志级别调整：

   • 调整日志级别，查看是否有更详细的错误信息。

解决方案

1. 检查依赖版本

确保你的 pom.xml 文件中的依赖版本是正确的，并且是兼容的。例如：

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>3.3.3</version>
</parent>

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>2023.0.3</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>

<dependencies>
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-openfeign</artifactId>
    </dependency>
</dependencies>

2. 确保 FallbackFactory 实现正确

确保 RemoteDemoFallbackFactory 类实现了 FallbackFactory 并且方法签名正确。你的实现看起来是正确的，但可以稍作调整以确保一致性：

package com.link.code.materialaudience.openfeign.fallback;

import com.link.code.materialaudience.openfeign.DemoClient;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.openfeign.FallbackFactory;
import org.springframework.stereotype.Component;

@Slf4j
@Component
public class RemoteDemoFallbackFactory implements FallbackFactory<DemoClient> {
    @Override
    public DemoClient create(Throwable cause) {
        return new DemoClient() {
            @Override
            public String port() {
                log.info("Invoke service failed: {}", cause.getMessage());
                return "exception---null";
            }
        };
    }
}

3. 检查配置文件

确保你的 application.yml 或 application.properties 文件中启用了 Feign 客户端：

# application.yml
spring:
  application:
    name: material-audience
  cloud:
    openfeign:
      client:
        config:
          default:
            connectTimeout: 5000
            readTimeout: 5000

4. 调整日志级别

增加日志级别以获取更多调试信息：

logging:
  level:
    com.link.code.materialaudience.openfeign: DEBUG
    org.springframework.cloud.openfeign: DEBUG

代码示例

确保你的 DemoClient 接口定义如下：

package com.link.code.materialaudience.openfeign;

import com.link.code.materialaudience.openfeign.fallback.RemoteDemoFallbackFactory;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.web.bind.annotation.GetMapping;

@FeignClient(value = "material-tsp", fallbackFactory = RemoteDemoFallbackFactory.class)
public interface DemoClient {

    @GetMapping("health/port")
    String port();
}

通过以上步骤，你应该能够解决 OpenFeign 的 FallbackFactory 在处理 500 Internal Server Error 时无效的问题。如果问题仍然存在，请检查是否有其他配置或环境因素影响。