Spring Cloud Gateway服务器启动期间出现问题？

Question

I have a simple Spring Cloud microservices system. I have a Cloud Gateway server in the application. It registers with Eureka, get the address of Config Server and downloads the config for itself.

This gateway service will be the place of login, and it also finds the right Microservice, what the client is really want to call. It is using Redis for session handling and distribution.

But during startup, I see this failure:

***************************
APPLICATION FAILED TO START
***************************

Description:

The bean 'sessionRepository', defined in class path resource     [org/springframework/boot/autoconfigure/session/RedisReactiveSessionConfiguration$SpringBootRedisWebSessionConfiguration.class], could not be registered. A bean with that name has already been defined in class path resource [org/springframework/session/data/redis/config/annotation/web/http/RedisHttpSessionConfiguration.class] and overriding is disabled.

Action:

Consider renaming one of the beans or enabling overriding by setting  spring.main.allow-bean-definition-overriding=true

[WARNING] 
java.lang.reflect.InvocationTargetException
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke0 (Native Method)
at jdk.internal.reflect.NativeMethodAccessorImpl.invoke (NativeMethodAccessorImpl.java:62)
at jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke (DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke (Method.java:566)
at org.springframework.boot.maven.AbstractRunMojo$LaunchRunner.run (AbstractRunMojo.java:558)
at java.lang.Thread.run (Thread.java:834)

Caused by: org.springframework.beans.factory.support.BeanDefinitionOverrideException: Invalid bean definition with name 'sessionRepository' defined in class path resource  [org/springframework/boot/autoconfigure/session/RedisReactiveSessionConfiguration$SpringBootRedisWebSessionConfiguration.class]: Cannot register bean definition [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=org.springframework.boot.autoconfigure.session.RedisReactiveSessionConfiguration$SpringBootRedisWebSessionConfiguration; factoryMethodName=sessionRepository; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/boot/autoconfigure/session/RedisReactiveSessionConfiguration$SpringBootRedisWebSessionConfiguration.class]] for bean 'sessionRepository': There is already [Root bean: class [null]; scope=; abstract=false; lazyInit=false; autowireMode=3; dependencyCheck=0; autowireCandidate=true; primary=false; factoryBeanName=org.springframework.session.data.redis.config.annotation.web.http.RedisHttpSessionConfiguration; factoryMethodName=sessionRepository; initMethodName=null; destroyMethodName=(inferred); defined in class path resource [org/springframework/session/data/redis/config/annotation/web/http/RedisHttpSessionConfiguration.class]] bound.

at  org.springframework.beans.factory.support.DefaultListableBeanFactory.registerBeanDefinition (DefaultListableBeanFactory.java:894)

Here is the pom.xml for the gateway app:

<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>

<artifactId>elszamolas-gateway</artifactId>
<packaging>jar</packaging>

<name>elszamolas-gateway</name>
<description>TAO elszamolas GATEWAY service</description>

<parent>
    <groupId>com.besztercekk.tao</groupId>
    <artifactId>tao-elszamolas</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <relativePath>../pom.xml</relativePath>
</parent>


<dependencies>
    <!-- Spring Cloud Gateway service -->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-gateway</artifactId>
    </dependency>

    <!-- Spring Cloud Eureka client -->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
    </dependency>

    <!-- Spring Cloud config client -->
    <dependency>
        <groupId>org.springframework.cloud</groupId>
        <artifactId>spring-cloud-config-client</artifactId>
    </dependency>

    <!-- Spring Boot reactive web -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-webflux</artifactId>
    </dependency>

    <!-- Spring Boot share session via Redis -->
    <dependency>
        <groupId>org.springframework.session</groupId>
        <artifactId>spring-session-data-redis</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-redis-reactive</artifactId>
    </dependency>

    <!-- Servlet API -->
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <scope>provided</scope>
    </dependency>
</dependencies>

<dependencyManagement>
    <dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-dependencies</artifactId>
            <version>${spring-cloud.version}</version>
            <type>pom</type>
            <scope>import</scope>
        </dependency>
    </dependencies>
</dependencyManagement>
</project>

And this is its parent pom.xml:

<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>

<groupId>com.besztercekk.tao</groupId>
<artifactId>tao-elszamolas</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>pom</packaging>

<name>elszamolas</name>
<description>TAO elszámolás szülő project</description>

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>2.1.1.RELEASE</version>
    <relativePath/> <!-- lookup parent from repository -->
</parent>

<properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
    <java.version>1.8</java.version>
    <spring-cloud.version>Greenwich.M3</spring-cloud.version>
    <spring-session.version>1.3.4.RELEASE</spring-session.version>
    <spring-session-core.version>2.1.2.RELEASE</spring-session-core.version>
</properties>

<modules>
    <module>elszamolas-config</module>
    <module>elszamolas-discovery</module>
    <module>elszamolas-gateway</module>
</modules>

<dependencies>

    <!-- Common Spring Boot Dependencies -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>

    <!-- Spring Security -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-security</artifactId>
    </dependency>

    <!-- Java 11 required dependencies -->
    <dependency>
        <groupId>javax.xml.bind</groupId>
        <artifactId>jaxb-api</artifactId>
    </dependency>
    <dependency>
        <groupId>com.sun.xml.bind</groupId>
        <artifactId>jaxb-core</artifactId>
        <version>2.3.0</version>
    </dependency>
    <dependency>
        <groupId>com.sun.xml.bind</groupId>
        <artifactId>jaxb-impl</artifactId>
        <version>2.3.1</version>
    </dependency>
    <dependency>
        <groupId>javax.activation</groupId>
        <artifactId>activation</artifactId>
        <version>1.1.1</version>
    </dependency>
</dependencies>

<repositories>
    <repository>
        <id>spring-milestones</id>
        <name>Spring Milestones</name>
        <url>https://repo.spring.io/milestone</url>
        <snapshots>
            <enabled>false</enabled>
        </snapshots>
    </repository>
</repositories>

<build>
    <plugins>
        <plugin>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-maven-plugin</artifactId>
        </plugin>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-compiler-plugin</artifactId>
            <configuration>
                <release>11</release>
            </configuration>
        </plugin>   
    </plugins>
</build>
</project>

Any help would be very much appreciated. I can't really find out why this " sessionRepository " bean is loaded multiple times, from multiple places. Did I mix up the necessary dependencies?

Answer 1

UPDATE:

I had a closer look on this issue. The exception is pretty clear the bean called, it says the bean sessionRepository is defined twice. If you check the classes where they defined, and where they are coming from, you'll find out that one of them is coming from autoconfigurator and the other one is from the Redis session data dependency.

At this point it pretty much looks like you need to allow the bean overriding, what you can easily do by adding this to bootstrap.yml :

spring:
  main:
    allow-bean-definition-overriding: true

But if you do that couple of other exceptions what you'll need to face. There is a point behind the guys made this option false by default. Here is a sample exception what you cab get:

2018-12-20 00:37:22.965 ERROR 3089 --- [           main] o.s.boot.SpringApplication               : Application run failed

org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'redisMessageListenerContainer' defined in class path resource     org/springframework/session/data/redis/config/annotation/web/http/RedisHttpSessionConfiguration.class]: Bean instantiation via factory method failed; nested exception is org.springframework.beans.BeanInstantiationException: Failed to instantiate [org.springframework.data.redis.listener.RedisMessageListenerContainer]: Factory method 'redisMessageListenerContainer' threw exception; nested exception is java.lang.IllegalStateException: @Bean method RedisHttpSessionConfiguration.sessionRepository called as bean reference for type [org.springframework.session.data.redis.RedisOperationsSessionRepository] but overridden by non-compatible bean instance of type [org.springframework.session.data.redis.ReactiveRedisOperationsSessionRepository]. Overriding bean of same name declared in: class path resource [org/springframework/boot/autoconfigure/session/RedisReactiveSessionConfiguration$SpringBootRedisWebSessionConfiguration.class]

Please, correct me if I'm wrong. I'd really appreciate that. But when you need the Spring boot auto configuration feature you just can't use Redis for session storage and distribution to microservices. It is just not working together. It's a bit hard to believe that, because there must be something what you can use in a Spring Boot 2.1.1 application when you really not want to authenticate your user in each and every microservice.