LoggerFactory is not a Logback LoggerContext but Logback is on the classpath. Either remove Logback or the competing implementation - maven

Question

I try to start my spring boot in tomcat server but when I'm adding some external jars to my project :
appsert-rt.jar
gf-client.jar
javaee.jar
it gives me that error :
Exception in thread "main" java.lang.IllegalArgumentException: LoggerFactory is not a Logback LoggerContext but Logback is on the classpath. Either remove Logback or the competing implementation (class org.slf4j.impl.JDK14LoggerFactory loaded from file:/C:/Users/amar/Documents/glassfish-3.1/glassfish/modules/bean-validator.jar). If you are using Weblogic you will need to add 'org.slf4j' to prefer-application-packages in WEB-INF/weblogic.xml Object of class [org.slf4j.impl.JDK14LoggerFactory] must be an instance of class ch.qos.logback.classic.LoggerContext
at org.springframework.util.Assert.isInstanceOf(Assert.java:339)
at org.springframework.boot.logging.logback.LogbackLoggingSystem.getLoggerContext(LogbackLoggingSystem.java:151)
at org.springframework.boot.logging.logback.LogbackLoggingSystem.getLogger(LogbackLoggingSystem.java:143)
at org.springframework.boot.logging.logback.LogbackLoggingSystem.beforeInitialize(LogbackLoggingSystem.java:89)
at org.springframework.boot.logging.LoggingApplicationListener.onApplicationStartedEvent(LoggingApplicationListener.java:132)
at org.springframework.boot.logging.LoggingApplicationListener.onApplicationEvent(LoggingApplicationListener.java:122)
at org.springframework.context.event.SimpleApplicationEventMulticaster.invokeListener(SimpleApplicationEventMulticaster.java:151)
at org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:128)
at org.springframework.boot.context.event.EventPublishingRunListener.publishEvent(EventPublishingRunListener.java:100)
at org.springframework.boot.context.event.EventPublishingRunListener.started(EventPublishingRunListener.java:54)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:278)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:961)
at org.springframework.boot.SpringApplication.run(SpringApplication.java:950)
at demo.DemoApplication.main(DemoApplication.java:14)
My pom :
<?xml version="1.0" encoding="UTF-8"?>
<projectxmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchemainstance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>org.udev</groupId>
<artifactId>udev</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>war</packaging>
<name>demo</name>
<description>Demo project for Spring Boot</description>
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.2.1.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<start-class>demo.DemoApplication</start-class>
<java.version>1.8</java.version>
</properties>
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-security</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-tomcat</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.apache.tomcat.embed</groupId>
<artifactId>tomcat-embed-jasper</artifactId>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.data</groupId>
<artifactId>spring-data-jpa</artifactId>
<version>1.6.4.RELEASE</version>
<type>jar</type>
</dependency>
<dependency>
<groupId>javax.servlet</groupId>
<artifactId>jstl</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.14.8</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jpa</artifactId>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
</build>
</project>
note : it work perfectly when i remove the jars / One problem could be conflits between classes of slf4j in my maven added jars and those added externelly

Answer 1

There is a conflict between the jars declared in your maven project and those you imported explicitly.
Dependency analysis is one of the great benefits of using a tool like Maven, but it cannot do anything about dependencies that you are manually adding a runtime.
What you should do is add those jars as dependencies to your maven project. Once you do that you can use the Maven Dependency Plugin to find the conflicting packages, and add exclusions for packages that conflict.