Maven打包后报错NoClassDefFoundError: org/slf4j/LoggerFactory

Question

<?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.project</groupId>
    <packaging>pom</packaging>
    <artifactId>encircle</artifactId>
    <version>1.0-SNAPSHOT</version>

    <modules>
        <module>project-service</module>
        <module>project-start</module>
    </modules>

    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <java.version>1.8</java.version>
        <io.vertx>3.5.1</io.vertx>
    </properties>


    <dependencyManagement>
        <dependencies>

            <dependency>
                <groupId>io.vertx</groupId>
                <artifactId>vertx-core</artifactId>
                <version>${io.vertx}</version>
            </dependency>

            <dependency>
                <groupId>org.slf4j</groupId>
                <artifactId>jcl-over-slf4j</artifactId>
                <version>1.7.25</version>
            </dependency>

            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>1.16.20</version>
            </dependency>

            <dependency>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-simple</artifactId>
                <version>1.8.0-alpha2</version>
            </dependency>

        </dependencies>
    </dependencyManagement>

    <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>1.8</source>
                    <target>1.8</target>
                </configuration>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-jar-plugin</artifactId>
                <configuration>
                    <archive>
                        <manifest>
                            <addClasspath>true</addClasspath>
                            <useUniqueVersions>false</useUniqueVersions>
                            <classpathPrefix>lib/</classpathPrefix>
                            <mainClass>com.project.start.GraduationMain</mainClass>
                        </manifest>
                    </archive>
                </configuration>
            </plugin>
        </plugins>
    </build>

</project>

补充

项目地址

https://github.com/wohuifude1...

加了之后依然不好使

打包还是那个错误

Answer 1

检查一下有没有slf4j-api.jar?如果没有加上依赖

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-api</artifactId>
    <version>1.6.1</version>
</dependency>

如果有了检查一下是否存在多个版本？