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

Question

I'm new to Spring and Maven. I'm trying to run the jar of a simple application but I'm receiving the following error:

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

This is the 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>

And this is the main class where SpringApplication is required:

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);
    }
}

Also I can see that the org.springframework.boot.SpringApplication is located exatly where it should be, within the Maven Dependencies library. So I'm not really sure what is going on which is causing this error.

Any idea?

Answer 1

This issue is due to spring-boot maven dependencies issue with your maven local repository

Try to delete local maven repository for spring-boot dependencies

{mvn_repo}\repository\org\springframework\boot - delete only boot dependencies.

From command line

mvn -U install

mvn spring-boot:run

Hope this helps

Answer 2

Copying and pasting the exact pom.xml written in the guide, made it work: 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 3

try below 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 4

you can try to upgrade the version of maven-jar-plugin to 3.0.2 and

<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>

if stile this occurring error then you can follow this stackoverflow link, question by soemirno where you can get may suitable answers by experts on this issue .

Answer 5

Add the spring boot plugin for maven

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