Question

更新：如果我只是将extension项目添加为master的依赖项，则会出现同样的错误。

更新2 ：我创建了一个Github仓库来重现错误：https://github.com/papagno/spring-factories-test

我正在尝试使用Spring Boot和spring.factories文件。所以我创建了两个简单的项目：

站长：
- 这是一个Spring Boot应用程序（1.4.3），其中包含starter-web和starter-actuator作为依赖项。
- 我还添加了<layout>ZIP</layout>作为spring-boot-maven-plugin的配置。
扩展
- 这是一个简单的Spring Boot应用程序（1.4.3），只有spring-boot-starter作为依赖项。
- 它包含resources/META-INF中的以下spring.factories文件： org.springframework.boot.autoconfigure.EnableAutoConfiguration=\ my.package.extension.ExtensionAutoConfiguration
- 它还包含仅my.package.ExtensionAutoConfiguration注释的@Configuration类，并声明@Bean：
```
package my.package.extension;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class ExtensionAutoConfiguration
{
    @Bean
    ExtensionService extensionService()
    {
        return new ExtensionService();
    }
}
```

我使用maven编译两个项目，将两个jar放在同一个文件夹中，然后使用以下命令运行master： java -Dloader.path=. -jar master-0.0.1-SNAPSHOT.jar

spring.factories已被识别，但当Spring尝试实例化我的自动配置类时，我得到该类的FileNotFoundException。

这是堆栈跟踪：

org.springframework.beans.factory.BeanDefinitionStoreException: Failed to process import candidates for configuration class [my.package.master.MasterApplication]; nested exception is java.lang.IllegalStateException: java.io.FileNotFoundException: class path resource [my/package/extension/ExtensionAutoConfiguration.class] cannot be opened because it does not exist
    at org.springframework.context.annotation.ConfigurationClassParser.processDeferredImportSelectors(ConfigurationClassParser.java:482) ~[spring-context-4.3.5.RELEASE.jar!/:4.3.5.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassParser.parse(ConfigurationClassParser.java:184) ~[spring-context-4.3.5.RELEASE.jar!/:4.3.5.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.processConfigBeanDefinitions(ConfigurationClassPostProcessor.java:308) ~[spring-context-4.3.5.RELEASE.jar!/:4.3.5.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassPostProcessor.postProcessBeanDefinitionRegistry(ConfigurationClassPostProcessor.java:228) ~[spring-context-4.3.5.RELEASE.jar!/:4.3.5.RELEASE]
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanDefinitionRegistryPostProcessors(PostProcessorRegistrationDelegate.java:270) ~[spring-context-4.3.5.RELEASE.jar!/:4.3.5.RELEASE]
    at org.springframework.context.support.PostProcessorRegistrationDelegate.invokeBeanFactoryPostProcessors(PostProcessorRegistrationDelegate.java:93) ~[spring-context-4.3.5.RELEASE.jar!/:4.3.5.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.invokeBeanFactoryPostProcessors(AbstractApplicationContext.java:686) ~[spring-context-4.3.5.RELEASE.jar!/:4.3.5.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:524) ~[spring-context-4.3.5.RELEASE.jar!/:4.3.5.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.4.3.RELEASE.jar!/:1.4.3.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:761) [spring-boot-1.4.3.RELEASE.jar!/:1.4.3.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:371) [spring-boot-1.4.3.RELEASE.jar!/:1.4.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:315) [spring-boot-1.4.3.RELEASE.jar!/:1.4.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1186) [spring-boot-1.4.3.RELEASE.jar!/:1.4.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1175) [spring-boot-1.4.3.RELEASE.jar!/:1.4.3.RELEASE]
    at my.package.master.MasterApplication.main(MasterApplication.java:10) [classes!/:0.0.1-SNAPSHOT]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_101]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_101]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_101]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_101]
    at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48) [master-0.0.1-SNAPSHOT.jar:0.0.1-SNAPSHOT]
    at org.springframework.boot.loader.Launcher.launch(Launcher.java:87) [master-0.0.1-SNAPSHOT.jar:0.0.1-SNAPSHOT]
    at org.springframework.boot.loader.Launcher.launch(Launcher.java:50) [master-0.0.1-SNAPSHOT.jar:0.0.1-SNAPSHOT]
    at org.springframework.boot.loader.PropertiesLauncher.main(PropertiesLauncher.java:521) [master-0.0.1-SNAPSHOT.jar:0.0.1-SNAPSHOT]
Caused by: java.lang.IllegalStateException: java.io.FileNotFoundException: class path resource [my/package/extension/ExtensionAutoConfiguration.class] cannot be opened because it does not exist
    at org.springframework.boot.autoconfigure.EnableAutoConfigurationImportSelector.selectImports(EnableAutoConfigurationImportSelector.java:94) ~[spring-boot-autoconfigure-1.4.3.RELEASE.jar!/:1.4.3.RELEASE]
    at org.springframework.context.annotation.ConfigurationClassParser.processDeferredImportSelectors(ConfigurationClassParser.java:474) ~[spring-context-4.3.5.RELEASE.jar!/:4.3.5.RELEASE]
    ... 22 common frames omitted
Caused by: java.io.FileNotFoundException: class path resource [my/package/extension/ExtensionAutoConfiguration.class] cannot be opened because it does not exist
    at org.springframework.core.io.ClassPathResource.getInputStream(ClassPathResource.java:172) ~[spring-core-4.3.5.RELEASE.jar!/:4.3.5.RELEASE]
    at org.springframework.core.type.classreading.SimpleMetadataReader.<init>(SimpleMetadataReader.java:50) ~[spring-core-4.3.5.RELEASE.jar!/:4.3.5.RELEASE]
    at org.springframework.core.type.classreading.SimpleMetadataReaderFactory.getMetadataReader(SimpleMetadataReaderFactory.java:98) ~[spring-core-4.3.5.RELEASE.jar!/:4.3.5.RELEASE]
    at org.springframework.boot.type.classreading.ConcurrentReferenceCachingMetadataReaderFactory.createMetadataReader(ConcurrentReferenceCachingMetadataReaderFactory.java:89) ~[spring-boot-1.4.3.RELEASE.jar!/:1.4.3.RELEASE]
    at org.springframework.boot.type.classreading.ConcurrentReferenceCachingMetadataReaderFactory.getMetadataReader(ConcurrentReferenceCachingMetadataReaderFactory.java:76) ~[spring-boot-1.4.3.RELEASE.jar!/:1.4.3.RELEASE]
    at org.springframework.core.type.classreading.SimpleMetadataReaderFactory.getMetadataReader(SimpleMetadataReaderFactory.java:93) ~[spring-core-4.3.5.RELEASE.jar!/:4.3.5.RELEASE]
    at org.springframework.boot.autoconfigure.AutoConfigurationSorter$AutoConfigurationClasses.<init>(AutoConfigurationSorter.java:110) ~[spring-boot-autoconfigure-1.4.3.RELEASE.jar!/:1.4.3.RELEASE]
    at org.springframework.boot.autoconfigure.AutoConfigurationSorter.getInPriorityOrder(AutoConfigurationSorter.java:54) ~[spring-boot-autoconfigure-1.4.3.RELEASE.jar!/:1.4.3.RELEASE]
    at org.springframework.boot.autoconfigure.EnableAutoConfigurationImportSelector.sort(EnableAutoConfigurationImportSelector.java:193) ~[spring-boot-autoconfigure-1.4.3.RELEASE.jar!/:1.4.3.RELEASE]
    at org.springframework.boot.autoconfigure.EnableAutoConfigurationImportSelector.selectImports(EnableAutoConfigurationImportSelector.java:89) ~[spring-boot-autoconfigure-1.4.3.RELEASE.jar!/:1.4.3.RELEASE]
    ... 23 common frames omitted

我做错了吗？我该怎么做才能了解发生了什么？谢谢。

Answer 1

您的扩展程序不能是Spring Boot应用程序（没有父spring-boot-starter-parent）。

当您将spring-boot-starter-parent声明为父级时，生成的jar将使用Sring-Boot风格重新打包，并且这些类不在预期的文件夹中。如果打开extension-0.0.1-SNAPSHOT.jar，则类在BOOT-INF / classes中，因此当jar用作库时，不会找到任何类。这些类需要位于jar内部的根目录。

对扩展项目使用以下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</groupId>
    <artifactId>extension</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <packaging>jar</packaging>

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

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>

    <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-parent</artifactId>
                <version>1.4.3.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
        </dependencies>
    </dependencyManagement>

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

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

        <dependency>
            <groupId>com.example</groupId>
            <artifactId>api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
    </dependencies>
</project>

在上面的代码示例中，我仍然将spring-boot-starter-parent声明为dependencyManagement - import，因此继承了版本声明。但是，spring-boot-maven-plugin将不会被执行，jar将不会被重新打包，它将可用作库。

使用spring.factories加载自定义自动配置时出现FileNotFoundException

1 个答案: