使用Spring Boot和Spring云的ClassNotFoundException

Question

我试图在Spring Boot微服务中使用Spring Cloud的特性（例如：Faign或Zipkin客户端）。每当我在pom中引入Spring云依赖时。xml I在启动时出现以下错误：

java.lang.ClassNotFoundException: com.fasterxml.jackson.core.Versioned
    at java.net.URLClassLoader.findClass(Unknown Source) ~[na:1.8.0_162]
    at java.lang.ClassLoader.loadClass(Unknown Source) ~[na:1.8.0_162]
    at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) ~[na:1.8.0_162]
    at java.lang.ClassLoader.loadClass(Unknown Source) ~[na:1.8.0_162]
    ... 36 common frames omitted

以下是导致此问题的示例pom.xml。我目前使用Spring Boot 2.0.0。RELEASE和Spring Cloud Finchley。M8。

我做错了什么？我应该切换到另一个版本的Spring Cloud吗？

更新：不是我做错了，甚至Spring Initializer项目也证明了这个问题。重新编程：

1. 转到https://start.spring.io/.

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>io.urig</groupId>
    <artifactId>inventory</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

    <name>inventory</name>
    <description>Demo project for Spring Boot</description>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.0.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.M8</spring-cloud.version>

    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.retry</groupId>
            <artifactId>spring-retry</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-zipkin</artifactId>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</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>

Answer 1

原来问题是Maven软件包损坏。删除我的<代码>。m2\repository文件夹和运行mvn spring boot：运行下载的依赖项并运行我的应用程序解决了问题。