Question

我是Spring和Maven的新手。我试图运行简单应用程序的jar但我收到以下错误：

java -jar target/gs-rest-service-0.0.1-SNAPSHOT.jar 
Exception in thread "main" java.lang.NoClassDefFoundError: org/springframework/boot/SpringApplication
    at hello.Application.main(Application.java:10)
Caused by: java.lang.ClassNotFoundException: org.springframework.boot.SpringApplication
    at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
    at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:335)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:357)
    ... 1 more

这是pom.xml：

<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>gs-rest-service</groupId>
  <artifactId>gs-rest-service</artifactId>
  <version>0.0.1-SNAPSHOT</version>
  <name>MyApp</name>
  <build>
    <plugins>
        <plugin>
            <groupId>org.apache.maven.plugins</groupId>
            <artifactId>maven-jar-plugin</artifactId>
            <version>2.4</version>
            <configuration>
                <archive>
                    <manifest>
                        <mainClass>hello.Application</mainClass>
                    </manifest>
                </archive>
            </configuration>
        </plugin>
    </plugins>
  </build>
  <dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-web</artifactId>
        <version>4.3.10.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot</artifactId>
        <version>1.5.5.RELEASE</version>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-autoconfigure</artifactId>
        <version>1.5.5.RELEASE</version>
    </dependency>
  </dependencies>
</project>

这是需要SpringApplication的主要类：

package hello;

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

@SpringBootApplication
public class Application {

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

此外，我可以看到org.springframework.boot.SpringApplication位于Maven依赖项库中的应有位置。因此，我不确定导致此错误的是什么。

有什么想法吗？

Answer 1

您可以尝试将maven-jar-plugin的版本升级为3.0.2和

<project>
  ...
  <build>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-jar-plugin</artifactId>
        <version>3.0.2</version>
        <configuration>
          <archive>
            <manifestFile>${project.build.outputDirectory}/META-INF/MANIFEST.MF</manifestFile>
          </archive>
        </configuration>
        ...
      </plugin>
    </plugins>
  </build>
  ...
</project>

如果出现这种错误，那么您可以按照this stackoverflow链接，soemirno提问，您可以在这个问题上获得专家的合适答案。

Answer 2

为maven添加spring boot插件

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

Answer 3

复制并粘贴指南中写的确切pom.xml，使其工作： https://spring.io/guides/gs/rest-service/

<?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>org.springframework</groupId>
    <artifactId>gs-rest-service</artifactId>
    <version>0.1.0</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>1.5.5.RELEASE</version>
    </parent>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>com.jayway.jsonpath</groupId>
            <artifactId>json-path</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <properties>
        <java.version>1.8</java.version>
    </properties>


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

    <repositories>
        <repository>
            <id>spring-releases</id>
            <url>https://repo.spring.io/libs-release</url>
        </repository>
    </repositories>
    <pluginRepositories>
        <pluginRepository>
            <id>spring-releases</id>
            <url>https://repo.spring.io/libs-release</url>
        </pluginRepository>
    </pluginRepositories>
</project>

Answer 4

尝试下面的pom： -

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.5.3.RELEASE</version>
</parent>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
    </dependency>
    <!-- tag::actuator[] -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-actuator</artifactId>
    </dependency>
    <!-- end::actuator[] -->
    <!-- tag::tests[] -->
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-test</artifactId>
        <scope>test</scope>
    </dependency>
    <!-- end::tests[] -->
</dependencies>

Answer 5

此问题是由于您的maven本地存储库存在spring-boot maven依赖项

尝试删除本地Maven存储库中的Spring-boot依赖项

{mvn_repo} \ repository \ org \ springframework \ boot-仅删除启动依赖项。

从命令行

mvn -U install

mvn spring-boot:run

希望这会有所帮助

java.lang.ClassNotFoundException：org.springframework.boot.SpringApplication with maven-jar-plugin

5 个答案: