2
votes

first i had a small issue with this class brave.sampler.Sampler

could not import this class, only imported when i added this dependency

   <dependency>
        <groupId>io.zipkin.brave</groupId>
        <artifactId>brave</artifactId>
        <version>4.0.5</version>
    </dependency>  

and my big problem is, when i tried to use zipkin for disturbed tracing, i added the required dependency but whenever i start the applications, it through an exception in start.

and this is the stack trace.

java.lang.IllegalStateException: Failed to introspect Class [org.springframework.cloud.sleuth.zipkin2.sender.ZipkinRabbitSenderConfiguration] from ClassLoader [sun.misc.Launcher$AppClassLoader@764c12b6]
    at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:659) ~[spring-core-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:556) ~[spring-core-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.util.ReflectionUtils.doWithMethods(ReflectionUtils.java:541) ~[spring-core-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.util.ReflectionUtils.getUniqueDeclaredMethods(ReflectionUtils.java:599) ~[spring-core-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.getTypeForFactoryMethod(AbstractAutowireCapableBeanFactory.java:718) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.determineTargetType(AbstractAutowireCapableBeanFactory.java:659) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.beans.factory.support.AbstractAutowireCapableBeanFactory.predictBeanType(AbstractAutowireCapableBeanFactory.java:627) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.beans.factory.support.AbstractBeanFactory.isFactoryBean(AbstractBeanFactory.java:1489) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.doGetBeanNamesForType(DefaultListableBeanFactory.java:419) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeanNamesForType(DefaultListableBeanFactory.java:389) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java:510) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.beans.factory.support.DefaultListableBeanFactory.getBeansOfType(DefaultListableBeanFactory.java:502) ~[spring-beans-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.getBeansOfType(AbstractApplicationContext.java:1198) ~[spring-context-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.boot.SpringApplication.getExitCodeFromMappedException(SpringApplication.java:892) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    at org.springframework.boot.SpringApplication.getExitCodeFromException(SpringApplication.java:878) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    at org.springframework.boot.SpringApplication.handleExitCode(SpringApplication.java:864) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    at org.springframework.boot.SpringApplication.handleRunFailure(SpringApplication.java:813) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:341) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1258) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1246) [spring-boot-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    at com.tutoriel.microservices.CurrencyExchangeServiceApplication.main(CurrencyExchangeServiceApplication.java:15) [classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_181]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_181]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_181]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_181]
    at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.0.4.RELEASE.jar:2.0.4.RELEASE]
Caused by: java.lang.NoClassDefFoundError: zipkin2/reporter/Sender
    at java.lang.Class.getDeclaredMethods0(Native Method) ~[na:1.8.0_181]
    at java.lang.Class.privateGetDeclaredMethods(Class.java:2701) ~[na:1.8.0_181]
    at java.lang.Class.getDeclaredMethods(Class.java:1975) ~[na:1.8.0_181]
    at org.springframework.util.ReflectionUtils.getDeclaredMethods(ReflectionUtils.java:641) ~[spring-core-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    ... 25 common frames omitted
Caused by: java.lang.ClassNotFoundException: zipkin2.reporter.Sender
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381) ~[na:1.8.0_181]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424) ~[na:1.8.0_181]
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:349) ~[na:1.8.0_181]
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357) ~[na:1.8.0_181]
    ... 29 common frames omitted

my pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<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.example.microservices</groupId>
    <artifactId>user-service</artifactId>
    <version>0.0.1</version>
    <packaging>jar</packaging>

    <name>user-service</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.4.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>Finchley.SR1</spring-cloud.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
           <groupId>com.h2database</groupId>
           <artifactId>h2</artifactId>
        </dependency>

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


       <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-sleuth-zipkin</artifactId>
        </dependency> 


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

           <!--  dependency required to use Sampler -->        
         <dependency>
            <groupId>io.zipkin.brave</groupId>
            <artifactId>brave</artifactId>
            <version>4.0.5</version>
        </dependency> 

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


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

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>


</project>

i would someone to help me fix those issues, also i want to understand why this exception comes, and why the sampler class does not imported only when i add it's dependency, but i see in other projects codes there are no needs for the dependency.

3
Looks like the class zipkin2.reporter.Sender is not on your classpath. It may be caused by version conflicts between the libraries you use. Pls check the zipkin2 upgrade notes, those may be helpful. - Vladimir Vagaytsev

3 Answers

3
votes

after many searches, i found that there are a version conflicts between the dependencies. and thanks for vladimir-vagaytsev

so, i see that spring-cloud-starter-sleuth imported as a different version.

to fix it i have added sleuth.version to properties in pom.xml like so.

<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>Finchley.SR1</spring-cloud.version>
        <sleuth.version>2.0.1.RELEASE</sleuth.version>
    </properties> 

then in dependency management we need to specify the version like so

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

after then remove unused dependencies build and run.

-1
votes

This class comes from zipkin-2. You can try adding this dependency.

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-sleuth-zipkin2</artifactId>
    <version>2.0.0.M3</version>
</dependency>
-1
votes

Cleare Issue Of Mismatching Dependencies Just Try To Adjust Dependencies Version Up and Down It Will Work...Mine Worked Like This