title: Unable to start embedded Tomcat - Spring Boot
body: <p>I am new to Spring Boot trying to learn and now i have a problem in running  Spring Data Rest using Spring boot.</p>
  
  <p>i wanted to build an application using  Spring Data REST with Spring Boot.</p>
  
  <p>Am facing the issue </p>
  
  <pre><code>Exception in thread "main" 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:133)
      at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:474)
      at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118)
      at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:686)
      at org.springframework.boot.SpringApplication.run(SpringApplication.java:320)
      at org.springframework.boot.SpringApplication.run(SpringApplication.java:957)
      at org.springframework.boot.SpringApplication.run(SpringApplication.java:946)
      at com.teamtreehouse.core.Application.main(Application.java:10)
  Caused by: org.springframework.boot.context.embedded.EmbeddedServletContainerException: Unable to start embedded Tomcat
      at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:98)
      at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.&lt;init&gt;(TomcatEmbeddedServletContainer.java:75)
      at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getTomcatEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:378)
      at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:155)
      at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.createEmbeddedServletContainer(EmbeddedWebApplicationContext.java:157)
      at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:130)
      ... 7 more
  Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardServer[-1]]
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
      at org.apache.catalina.startup.Tomcat.start(Tomcat.java:342)
      at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:88)
      ... 12 more
  Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Tomcat]]
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
      at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:739)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
      ... 14 more
  Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat]]
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
      at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
      ... 16 more
  Caused by: org.apache.catalina.LifecycleException: A child container failed during start
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1131)
      at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:300)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
      ... 18 more
  2017-03-24 17:04:07.808 ERROR 8312 --- [           main] o.s.boot.SpringApplication               : Application startup failed
  
  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:133)
      at org.springframework.context.support.AbstractApplicationContext.refresh(AbstractApplicationContext.java:474)
      at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.refresh(EmbeddedWebApplicationContext.java:118)
      at org.springframework.boot.SpringApplication.refresh(SpringApplication.java:686)
      at org.springframework.boot.SpringApplication.run(SpringApplication.java:320)
      at org.springframework.boot.SpringApplication.run(SpringApplication.java:957)
      at org.springframework.boot.SpringApplication.run(SpringApplication.java:946)
      at com.teamtreehouse.core.Application.main(Application.java:10)
  Caused by: org.springframework.boot.context.embedded.EmbeddedServletContainerException: Unable to start embedded Tomcat
      at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:98)
      at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.&lt;init&gt;(TomcatEmbeddedServletContainer.java:75)
      at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getTomcatEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:378)
      at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainerFactory.getEmbeddedServletContainer(TomcatEmbeddedServletContainerFactory.java:155)
      at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.createEmbeddedServletContainer(EmbeddedWebApplicationContext.java:157)
      at org.springframework.boot.context.embedded.EmbeddedWebApplicationContext.onRefresh(EmbeddedWebApplicationContext.java:130)
      ... 7 common frames omitted
  Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardServer[-1]]
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
      at org.apache.catalina.startup.Tomcat.start(Tomcat.java:342)
      at org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.initialize(TomcatEmbeddedServletContainer.java:88)
      ... 12 common frames omitted
  Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Tomcat]]
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
      at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:739)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
      ... 14 common frames omitted
  Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat]]
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
      at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
      ... 16 common frames omitted
  Caused by: org.apache.catalina.LifecycleException: A child container failed during start
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1131)
      at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:300)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
      ... 18 common frames omitted
  </code></pre>
  
  <p>pom.xml</p>
  
  <pre><code>&lt;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/maven-v4_0_0.xsd"&gt;
      &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
      &lt;groupId&gt;com.team&lt;/groupId&gt;
      &lt;artifactId&gt;course-reviews-api&lt;/artifactId&gt;
      &lt;version&gt;0.0.1-SNAPSHOT&lt;/version&gt;
      &lt;name&gt;course-reviews-api Maven Webapp&lt;/name&gt;
      &lt;url&gt;http://maven.apache.org&lt;/url&gt;
  
      &lt;properties&gt;
          &lt;maven.compiler.source&gt;1.8&lt;/maven.compiler.source&gt;
          &lt;maven.compiler.target&gt;1.8&lt;/maven.compiler.target&gt;
      &lt;/properties&gt;
      &lt;dependencies&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;junit&lt;/groupId&gt;
              &lt;artifactId&gt;junit&lt;/artifactId&gt;
              &lt;version&gt;3.8.1&lt;/version&gt;
              &lt;scope&gt;test&lt;/scope&gt;
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;javax.servlet&lt;/groupId&gt;
              &lt;artifactId&gt;servlet-api&lt;/artifactId&gt;
              &lt;version&gt;2.5&lt;/version&gt;
          &lt;/dependency&gt;
          &lt;!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-data-rest --&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-starter-data-rest&lt;/artifactId&gt;
              &lt;/dependency&gt;
          &lt;!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-data-jpa --&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;org.springframework.boot&lt;/groupId&gt;
              &lt;artifactId&gt;spring-boot-starter-data-jpa&lt;/artifactId&gt;
  
          &lt;/dependency&gt;
          &lt;dependency&gt;
              &lt;groupId&gt;com.h2database&lt;/groupId&gt;
              &lt;artifactId&gt;h2&lt;/artifactId&gt;
  
              &lt;scope&gt;runtime&lt;/scope&gt;
          &lt;/dependency&gt;
      &lt;/dependencies&gt;
      &lt;dependencyManagement&gt;
          &lt;dependencies&gt;
              &lt;dependency&gt;
                  &lt;groupId&gt;io.spring.platform&lt;/groupId&gt;
                  &lt;artifactId&gt;platform-bom&lt;/artifactId&gt;
                  &lt;version&gt;1.1.2.RELEASE&lt;/version&gt;
                  &lt;type&gt;pom&lt;/type&gt;
                  &lt;scope&gt;import&lt;/scope&gt;
              &lt;/dependency&gt;
          &lt;/dependencies&gt;
      &lt;/dependencyManagement&gt;
      &lt;build&gt;
          &lt;finalName&gt;course-reviews-api&lt;/finalName&gt;
  
    &lt;plugins&gt;
        &lt;plugin&gt;
            &lt;groupId&gt;org.apache.maven.plugins&lt;/groupId&gt;
            &lt;artifactId&gt;maven-compiler-plugin&lt;/artifactId&gt;
            &lt;version&gt;3.1&lt;/version&gt;
            &lt;configuration&gt;
                &lt;source&gt;1.8&lt;/source&gt;
                &lt;target&gt;1.8&lt;/target&gt;
            &lt;/configuration&gt;
        &lt;/plugin&gt;
    &lt;/plugins&gt;
  &lt;/build&gt;
  
  &lt;/project&gt;
  </code></pre>