原因：java.io.IOException：无法打开根 Jar 文件'file:/.../Sample/my-app/target/lib/spring-boot-actuator-autocon

Question

我使用maven创建了一个简单的SpringBoot项目，我唯一存在的类是包含

的App.java

package com.mycompany.app;
// import org.slf4j.Logger;
// import org.slf4j.LoggerFactory;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
@RestController
public class App {
// Logger logger = LoggerFactory.getLogger(App.class);

@GetMapping("/test-docker")
public String getData() {
return "in docker tutorial project of example";
}
public static void main( String[] args )
{
// System.out.println("SOP method");
SpringApplication.run(App.class, args);
}
}

这是我的pom.xml文件:

<?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>2.1.0.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<groupId>com.mycompany.app</groupId>
<artifactId>my-app</artifactId>
<version>1.0-SNAPSHOT</version>
<name>my-app</name>
<!-- FIXME change it to the project's website -->
<url>http://www.example.com</url>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<maven.compiler.source>11</maven.compiler.source>
<maven.compiler.target>11</maven.compiler.target>
<java.version>11</java.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.boot</groupId>
<artifactId>spring-boot-devtools</artifactId>
<scope>runtime</scope>
<optional>true</optional>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-api</artifactId>
<version>2.14.1</version>
</dependency>
<dependency>
<groupId>org.apache.logging.log4j</groupId>
<artifactId>log4j-core</artifactId>
<version>2.14.1</version>
</dependency>
</dependencies>
<build>
<!-- <pluginManagement>lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
<plugins>
<plugin>
<artifactId>maven-dependency-plugin</artifactId>
<executions>
<execution>
<phase>install</phase>
<goals>
<goal>copy-dependencies</goal>
</goals>
<configuration>
<outputDirectory>${project.build.directory}/lib</outputDirectory>
</configuration>
</execution>
</executions>
</plugin>
<plugin>
<!-- Build an executable JAR -->
<groupId>org.apache.maven.plugins</groupId>
<artifactId>maven-jar-plugin</artifactId>
<version>3.1.0</version>
<configuration>
<archive>
<manifest>
<addClasspath>true</addClasspath>
<classpathPrefix>lib/</classpathPrefix>
<mainClass>com.mycompany.app.App</mainClass>
</manifest>
</archive>
</configuration>
</plugin>
<!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle -->
<plugin>
<artifactId>maven-clean-plugin</artifactId>
<version>3.1.0</version>
</plugin>
<!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
<plugin>
<artifactId>maven-resources-plugin</artifactId>
<version>3.0.2</version>
</plugin>
<plugin>
<artifactId>maven-compiler-plugin</artifactId>
<version>3.8.0</version>
</plugin>
<plugin>
<artifactId>maven-surefire-plugin</artifactId>
<version>2.22.1</version>
</plugin>
<plugin>
<artifactId>maven-jar-plugin</artifactId>
<version>3.0.2</version>
</plugin>
<plugin>
<artifactId>maven-install-plugin</artifactId>
<version>2.5.2</version>
</plugin>
<plugin>
<artifactId>maven-deploy-plugin</artifactId>
<version>2.8.2</version>
</plugin>
<!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle -->
<plugin>
<artifactId>maven-site-plugin</artifactId>
<version>3.7.1</version>
</plugin>
<plugin>
<artifactId>maven-project-info-reports-plugin</artifactId>
<version>3.0.0</version>
</plugin>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
<!-- </pluginManagement> -->
</build>
</project>

当我执行mvn安装时，jar文件将在我的目标目录中创建。当我运行以下命令时，

java -jar target/my-app-1.0-SNAPSHOT.jar

我得到错误:

lrd72218673:my-app subnara$ java -jar target/my-app-1.0-SNAPSHOT.jar 
ERROR StatusLogger Log4j2 could not find a logging implementation. Please add log4j-core to the classpath. Using SimpleLogger to log to the console...
Exception in thread "main" java.lang.reflect.InvocationTargetException
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:78)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:567)
at org.springframework.boot.loader.MainMethodRunner.run(MainMethodRunner.java:48)
at org.springframework.boot.loader.Launcher.launch(Launcher.java:87)
at org.springframework.boot.loader.Launcher.launch(Launcher.java:50)
at org.springframework.boot.loader.JarLauncher.main(JarLauncher.java:51)
Caused by: java.lang.IllegalArgumentException: Unable to load factories from location [META-INF/spring.factories]
at org.springframework.core.io.support.SpringFactoriesLoader.loadSpringFactories(SpringFactoriesLoader.java:151)
at org.springframework.core.io.support.SpringFactoriesLoader.loadFactoryNames(SpringFactoriesLoader.java:122)
at org.springframework.boot.SpringApplication.getSpringFactoriesInstances(SpringApplication.java:428)
at org.springframework.boot.SpringApplication.getSpringFactoriesInstances(SpringApplication.java:420)
at org.springframework.boot.SpringApplication.<init>(SpringApplication.java:268)
at org.springframework.boot.SpringApplication.<init>(SpringApplication.java:249)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1260)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:1248)
at com.mycompany.app.App.main(App.java:24)
... 8 more
Caused by: java.io.IOException: Unable to open root Jar file 'file:/Users/subnara/Documents/Code/DevOps/MicroServices+Docker+Kubernetes/Sample/my-app/target/lib/spring-boot-actuator-autoconfigure-2.1.0.RELEASE.jar'
at org.springframework.boot.loader.jar.Handler.getRootJarFile(Handler.java:344)
at org.springframework.boot.loader.jar.Handler.getRootJarFileFromUrl(Handler.java:325)
at org.springframework.boot.loader.jar.Handler.openConnection(Handler.java:99)
at java.base/java.net.URL.openConnection(URL.java:1126)
at org.springframework.core.io.UrlResource.getInputStream(UrlResource.java:170)
at org.springframework.core.io.support.PropertiesLoaderUtils.fillProperties(PropertiesLoaderUtils.java:133)
at org.springframework.core.io.support.PropertiesLoaderUtils.loadProperties(PropertiesLoaderUtils.java:122)
at org.springframework.core.io.support.SpringFactoriesLoader.loadSpringFactories(SpringFactoriesLoader.java:139)
... 16 more
Caused by: java.lang.IllegalArgumentException: File /Users/subnara/Documents/Code/DevOps/MicroServices Docker Kubernetes/Sample/my-app/target/lib/spring-boot-actuator-autoconfigure-2.1.0.RELEASE.jar must exist
at org.springframework.boot.loader.data.RandomAccessDataFile$FileAccess.openIfNecessary(RandomAccessDataFile.java:234)
at org.springframework.boot.loader.data.RandomAccessDataFile$FileAccess.<init>(RandomAccessDataFile.java:216)
at org.springframework.boot.loader.data.RandomAccessDataFile$FileAccess.<init>(RandomAccessDataFile.java:206)
at org.springframework.boot.loader.data.RandomAccessDataFile.<init>(RandomAccessDataFile.java:49)
at org.springframework.boot.loader.jar.JarFile.<init>(JarFile.java:88)
at org.springframework.boot.loader.jar.Handler.getRootJarFile(Handler.java:338)
... 23 more

在这方面我是个新手，任何帮助都是非常感谢的。

Answer 1

TL;使用spring-boot-maven-pluginmaven插件并查看https://start.spring.io/。

当我试图重现这个问题时:

• 创建一个文件夹，其中包含指定的pom.xml和App.java文件
• runmvn install in the folder
• runjava -jar target/my-app-1.0-SNAPSHOT.jar

我没有遇到这个问题。

由于我们使用相同的代码(假设您的问题包含与您使用的相同的代码)，我想知道问题是否可能与您的Maven和Java版本有关。我使用的是Maven 3.6.3和java 11.0.11。

话虽如此，我注意到您的pom中的构建配置相当复杂。使用spring-boot-maven-plugin可以显著简化。

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

由于你的问题似乎与缺少库有关，并且这个spring-boot插件也处理将这些库添加到生成的jar中，切换到这个插件也可能解决你的问题。

既然你提到你刚刚创建了这个项目，我想建议你看看https://start.spring.io/。引导新的春季启动项目是一件很困难的事情。一个优点，也是我向您推荐它的原因，是它生成一个应该工作的项目。你不需要弄清楚要添加哪些插件或依赖项，生成器会为你做这些。