Unable to start embedded tomcat Spring boot

I’m working on Spring Boot Gradle application. My app is throwing error when i try to run it as a war by doing booRun. The error says : Unable to start embedded tomcat.
The contents of build.gradle file :

    group 'com.example'
    version '1.0-SNAPSHOT'



bootRepackage {
    mainClass = 'com.ex.MainClass'
}


apply plugin: 'war'
apply plugin: 'propdeps'

war {
    baseName = 'abc'
    archiveName 'abc.war'

}

repositories{
//    mavenLocal()
    mavenCentral()
}


dependencies {

        compile("org.springframework.boot:spring-boot-starter-web")
        compile("org.springframework.boot:spring-boot-starter-data-jpa")
        compile("io.springfox:springfox-swagger2:2.7.0")
        compile("io.springfox:springfox-swagger-ui:2.7.0")
        compile fileTree(dir:"lib", include:"*.jar")
        compile('org.springframework.boot:spring-boot-starter-mail')
        optional("org.springframework.boot:spring-boot-configuration-processor")
        compile("org.springframework.boot:spring-boot-starter-tomcat")
        compile "io.springfox:springfox-swagger2:2.7.0"
        compile 'io.springfox:springfox-swagger-ui:2.7.0'
        compile("org.springframework.boot:spring-boot-starter-amqp")
    }

   compileJava.dependsOn(processResources)

The whole stack trace is given below :

org.springframework.context.ApplicationContextException: Unable to start embedded container; nested exception is org.springframework.boot.context.embedded.EmbeddedServletContainerException: Unable to start embedded Tomcat
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:137) ~[spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
    at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:536) ~[spring-context-4.3.8.RELEASE.jar:4.3.8.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:122) ~[spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
    at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:737) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
    at org.springframework.boot.SpringApplication.refreshContext(SpringApplication.java:370) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:314) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1162) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
    at org.springframework.boot.SpringApplication.run(SpringApplication.java:1151) [spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
    at com.ex.MainClass.main(MainClass.java:38) [main/:na]
Caused by: org.springframework.boot.context.embedded.EmbeddedServletContainerException: Unable to start embedded Tomcat
    at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:123) ~[spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
    at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.<init>(TomcatEmbeddedServletContainer.java:84) ~[spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
    at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getTomcatEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:554) ~[spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
    at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:179) ~[spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.createEmbeddedServletContainer(EmbeddedWebApplicationContext.java:164) ~[spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
    at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:134) ~[spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
    ... 8 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardServer[-1]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.startup.Tomcat.start(Tomcat.java:344) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:99) ~[spring-boot-1.5.3.RELEASE.jar:1.5.3.RELEASE]
    ... 13 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Tomcat]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:793) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    ... 15 common frames omitted
Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:167) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.core.StandardService.startInternal(StandardService.java:422) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    ... 17 common frames omitted
Caused by: org.apache.catalina.LifecycleException: A child container failed during start
    at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:947) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ~[tomcat-embed-core-8.5.14.jar:8.5.14]
    ... 19 common frames omitted

bootRun FAILED

Can anybody please tell me why my app fails to start on embedded tomcat?

Thanks