新创建的 Spring boot starter 项目启动时抛出 ClassNotFoundException

Question

我在 Eclipse 中使用 Spring Tools 3 add on 创建了一个新的 Spring Boot 项目。当我尝试运行基本应用程序时，它会抛出 ClassNotFoundExcecption。

我正在尝试将此应用程序用作 Spring Cloud Config Server。最初它还显示了 TextEncyptor 类的 ClassNotFoundException，然后我添加了解决它的 spring-security 支持。但是有了这个，我无法弄清楚我缺少哪个依赖项。我尝试添加对网络、执行器的支持，但没有任何效果。是版本问题吗？如果是这样，我该如何解决？此外，这是一个自动生成的项目。

Here's 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>
           <parent>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-parent</artifactId>
                <version>2.1.1.RELEASE</version>
                <relativePath/> <!-- lookup parent from repository -->
            </parent>
            <groupId>com.microservices</groupId>
            <artifactId>spring-cloud-config-server</artifactId>
            <version>0.0.1-SNAPSHOT</version>
            <name>spring-cloud-config-server</name>
            <description>Demo project for Spring Boot</description>

        <properties>
            <java.version>1.8</java.version>
            <spring-cloud.version>Greenwich.RC2</spring-cloud.version>
        </properties>

        <dependencies>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-config-server</artifactId>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-security</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>

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

这是 StackTrace：

java.lang.ClassCastException: java.lang.ClassNotFoundException cannot be cast to [Ljava.lang.Object;
at org.springframework.boot.context.properties.EnableConfigurationPropertiesImportSelector$ConfigurationPropertiesBeanRegistrar.lambda$collectClasses$1(EnableConfigurationPropertiesImportSelector.java:83) ~[spring-boot-2.1.1.RELEASE.jar:2.1.1.RELEASE]
at java.util.stream.ReferencePipeline$7$1.accept(Unknown Source) ~[na:1.8.0_181]
at java.util.LinkedList$LLSpliterator.forEachRemaining(Unknown Source) ~[na:1.8.0_181]
at java.util.stream.AbstractPipeline.copyInto(Unknown Source) ~[na:1.8.0_181]
at java.util.stream.AbstractPipeline.wrapAndCopyInto(Unknown Source) ~[na:1.8.0_181]
at java.util.stream.ReduceOps$ReduceOp.evaluateSequential(Unknown Source) ~[na:1.8.0_181]
at java.util.stream.AbstractPipeline.evaluate(Unknown Source) ~[na:1.8.0_181]
at java.util.stream.ReferencePipeline.collect(Unknown Source) ~[na:1.8.0_181]
at org.springframework.boot.context.properties.EnableConfigurationPropertiesImportSelector$ConfigurationPropertiesBeanRegistrar.collectClasses(EnableConfigurationPropertiesImportSelector.java:85) ~[spring-boot-2.1.1.RELEASE.jar:2.1.1.RELEASE]
at org.springframework.boot.context.properties.EnableConfigurationPropertiesImportSelector$ConfigurationPropertiesBeanRegistrar.getTypes(EnableConfigurationPropertiesImportSelector.java:78) ~[spring-boot-2.1.1.RELEASE.jar:2.1.1.RELEASE]
at org.springframework.boot.context.properties.EnableConfigurationPropertiesImportSelector$ConfigurationPropertiesBeanRegistrar.registerBeanDefinitions(EnableConfigurationPropertiesImportSelector.java:70) ~[spring-boot-2.1.1.RELEASE.jar:2.1.1.RELEASE]
at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.lambda$loadBeanDefinitionsFromRegistrars$1(ConfigurationClassBeanDefinitionReader.java:364) ~[spring-context-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at java.util.LinkedHashMap.forEach(Unknown Source) ~[na:1.8.0_181]
at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsFromRegistrars(ConfigurationClassBeanDefinitionReader.java:363) ~[spring-context-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitionsForConfigurationClass(ConfigurationClassBeanDefinitionReader.java:145) ~[spring-context-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at org.springframework.context.annotation.ConfigurationClassBeanDefinitionReader.loadBeanDefinitions(ConfigurationClassBeanDefinitionReader.java:117) ~[spring-context-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:327) ~[spring-context-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:232) ~[spring-context-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:275) ~[spring-context-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:95) ~[spring-context-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:691) ~[spring-context-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:528) ~[spring-context-5.1.3.RELEASE.jar:5.1.3.RELEASE]
at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:775) [spring-boot-2.1.1.RELEASE.jar:2.1.1.RELEASE]
at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:397) [spring-boot-2.1.1.RELEASE.jar:2.1.1.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:316) [spring-boot-2.1.1.RELEASE.jar:2.1.1.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260) [spring-boot-2.1.1.RELEASE.jar:2.1.1.RELEASE]
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248) [spring-boot-2.1.1.RELEASE.jar:2.1.1.RELEASE]
at com.microservices.springcloudconfigserver.SpringCloudConfigServerApplication.main(SpringCloudConfigServerApplication.java:10) [classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_181]
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_181]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_181]
at java.lang.reflect.Method.invoke(Unknown Source) ~[na:1.8.0_181]
at org.springframework.boot.devtools.restart.RestartLauncher.run(RestartLauncher.java:49) [spring-boot-devtools-2.1.1.RELEASE.jar:2.1.1.RELEASE]

主类：

  import org.springframework.boot.SpringApplication;
  import org.springframework.boot.autoconfigure.SpringBootApplication;

  @SpringBootApplication
    public class SpringCloudConfigServerApplication {
        public static void main(String[] args) {
            SpringApplication.run(SpringCloudConfigServerApplication.class, args);
        }
    }

Answer 1

基于其他类似的问题 - 这可能是一个 Maven 缓存问题。我建议清除 .m2 文件夹并尝试重新构建。

在此处查看类似问题： https://github.com/spring-io/initializr/issues/457

另一个但没有反馈： https://github.com/spring-projects/spring-boot/issues/12466

我能够使用您的 pom.xml 以及 application.yml 中的主类和基本配置在本地运行该项目。

另一个建议 - 尝试排除 IDE 可能出现的问题，尝试使用

运行您的项目

mvn spring-boot:run 

希望这会有所帮助。