java.lang.ClassNotFoundException: feign.optionals.OptionalDecoder about spring-cloud-openfeign

[fengyws]

1.) 2.0.0.M2 can not find spring-cloud-openfeign-core, and find the spring-cloud-netflix-core
2. )because lack the jar

<dependency>
         <groupId>io.github.openfeign</groupId>
         <artifactId>feign-java8</artifactId>
 </dependency>

[ryanjbaxter]

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1.) spring-cloud-openfeign-core is part of spring-cloud-starter-openfeign so you should not need to add it
https://github.com/spring-cloud/spring-cloud-openfeign/blob/v2.0.0.M2/spring-cloud-starter-openfeign/pom.xml#L28

2.) I dont know what this means

in my project, when dependency other *.jar(the jar is feign project)

[ryanjbaxter]

1.) There have been some problems with the moving the code and the jar naming in maven repos. Clean you local maven repo and try your build again.

2.) You should not need to include any additional feign jars. sounds like a pom misconfiguration

[fengyws]

thanks，i try

[keyantec]

@ryanjbaxter I have the same problem, 2.0.0.M2 can not find spring-cloud-openfeign-core，you can see the newest pom
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <parent> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix</artifactId> <version>2.0.0.M2</version> </parent> <artifactId>spring-cloud-starter-openfeign</artifactId> <name>Spring Cloud Starter OpenFeign</name> <description>Spring Cloud Starter OpenFeign</description> <url>https://projects.spring.io/spring-cloud</url> <organization> <name>Pivotal Software, Inc.</name> <url>https://www.spring.io</url> </organization> <properties> <main.basedir>${basedir}/../../..</main.basedir> </properties> <dependencies> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-netflix-core</artifactId> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-commons</artifactId> </dependency> <dependency> <groupId>io.github.openfeign</groupId> <artifactId>feign-core</artifactId> </dependency> <dependency> <groupId>io.github.openfeign</groupId> <artifactId>feign-slf4j</artifactId> </dependency> <dependency> <groupId>io.github.openfeign</groupId> <artifactId>feign-hystrix</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-ribbon</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-netflix-archaius</artifactId> </dependency> </dependencies> </project>
I include the feign core in this way:
<dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-openfeign-core</artifactId> <version>2.0.0.M2</version> </dependency>
,there is no problem when compile,bug when I run the program ,has error:
Caused by: org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'com.xiaoke.teach.spring.cloud.base.FeignClientTest': FactoryBean threw exception on object creation; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'feignDecoder' defined in org.springframework.cloud.openfeign.FeignClientsConfiguration: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [feign.codec.Decoder]: Factory method 'feignDecoder' threw exception; nested exception is java.lang.NoClassDefFoundError: feign/optionals/OptionalDecoder

[keyantec]

@ryanjbaxter I see the pom in the github project , bug when you download the jar with maven, it is different, I think that the change is not upload to maven repo.

[keyantec]

@ryanjbaxter
<dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-starter-openfeign</artifactId> </dependency> <dependency> <groupId>org.springframework.cloud</groupId> <artifactId>spring-cloud-openfeign-core</artifactId> <version>2.0.0.M2</version> </dependency> <dependency> <groupId>io.github.openfeign</groupId> <artifactId>feign-java8</artifactId> <version>9.6.0</version> </dependency>
I need to include three jars that project can run OK.

[ryanjbaxter]

There was a couple problems with old jars in certain repos for M2. Finchley.RC1 was just released try that instead.

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[henzer]

Hi @keyantec, there is no need to add feign-java8 library. The OptionalDecoder class was added into feign-core since 10.0.0 version. You should update it