Eu sou novo na inicialização por mola e quando tento iniciar meu servidor, recebo a seguinte exceção. Entendo que isso tem algo a ver com conflitos de dependência, mas ainda não consigo descobrir. Estou usando o maven para gerenciar minhas dependências.

 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.Log4jLoggerFactory) Object of class
 [org.slf4j.impl.Log4jLoggerFactory] 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.initialize(LogbackLoggingSystem.java:93)
        at
org.springframework.boot.logging.AbstractLoggingSystem.initializeWithSensibleDefaults(AbstractLoggingSystem.java:62)
        at

 org.springframework.boot.logging.AbstractLoggingSystem.beforeInitialize(AbstractLoggingSystem.java:45)
    at

org.springframework.boot.logging.logback.LogbackLoggingSystem.beforeInitialize(LogbackLoggingSystem.java:69)
    at

 org.springframework.boot.logging.LoggingApplicationListener.onApplicationEvent(LoggingApplicationListener.java:135)
    at

 org.springframework.context.event.SimpleApplicationEventMulticaster.multicastEvent(SimpleApplicationEventMulticaster.java:98)
    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:276)
    at

 org.springframework.boot.SpringApplication.run(SpringApplication.java:952)
    at

 org.springframework.boot.SpringApplication.run(SpringApplication.java:941)
    at org.magnum.mobilecloud.video.Application.main(Application.java:30)

Resolvido: adicione o seguinte ao POM.xml

    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-web</artifactId>
        <exclusions>
            <exclusion>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-tomcat</artifactId>
            </exclusion>
            <exclusion>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-logging</artifactId>
            </exclusion>
    </exclusions>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-log4j</artifactId>
    </dependency>