title: I am getting java.util.concurrent.ExecutionException error when i try to run my web service using jersey framework
body: <p>I am using Jersey Framework and postgresql as a database.creating a webservice for the employee management.
  I am using Eclipse neon, jeresy framework v1.8 ,jre7 and tomcat 7 for the Developement Environment.</p>
  
  <p><strong>Getting below Error on eclipse console :</strong></p>
  
  <pre><code>&lt;?xml version="1.0" encoding="UTF-8"?&gt;
  &lt;web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://java.sun.com/xml/ns/javaee" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd" id="WebApp_ID" version="3.0"&gt;
    &lt;display-name&gt;employee&lt;/display-name&gt;
    &lt;welcome-file-list&gt;
      &lt;welcome-file&gt;index.html&lt;/welcome-file&gt;
      &lt;welcome-file&gt;index.htm&lt;/welcome-file&gt;
      &lt;welcome-file&gt;index.jsp&lt;/welcome-file&gt;
      &lt;welcome-file&gt;default.html&lt;/welcome-file&gt;
      &lt;welcome-file&gt;default.htm&lt;/welcome-file&gt;
      &lt;welcome-file&gt;default.jsp&lt;/welcome-file&gt;
    &lt;/welcome-file-list&gt;
    &lt;servlet&gt;
          &lt;servlet-name&gt;Employee-servlet&lt;/servlet-name&gt;
          &lt;servlet-class&gt;
                       com.sun.jersey.spi.container.servlet.ServletContainer
                  &lt;/servlet-class&gt;
          &lt;init-param&gt;
               &lt;param-name&gt;com.sun.jersey.config.property.packages&lt;/param-name&gt;
               &lt;param-value&gt;employee&lt;/param-value&gt;
          &lt;/init-param&gt;
          &lt;load-on-startup&gt;1&lt;/load-on-startup&gt;
      &lt;/servlet&gt;
  
      &lt;servlet-mapping&gt;
          &lt;servlet-name&gt;jersey-servlet&lt;/servlet-name&gt;
          &lt;url-pattern&gt;/rest/*&lt;/url-pattern&gt;
      &lt;/servlet-mapping&gt;
  &lt;/web-app&gt;
  </code></pre>
  
  <hr>
  
  <pre><code>java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/employee]]
      at java.util.concurrent.FutureTask.report(Unknown Source)
      at java.util.concurrent.FutureTask.get(Unknown Source)
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:915)
      at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:871)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1407)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1397)
      at java.util.concurrent.FutureTask.run(Unknown Source)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
      at java.lang.Thread.run(Unknown Source)
  Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/employee]]
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:162)
      ... 6 more
  Caused by: java.lang.IllegalArgumentException: Servlet mapping specifies an unknown servlet name jersey-serlvet
      at org.apache.catalina.core.StandardContext.addServletMappingDecoded(StandardContext.java:3191)
      at org.apache.catalina.core.StandardContext.addServletMappingDecoded(StandardContext.java:3182)
      at org.apache.catalina.startup.ContextConfig.configureContext(ContextConfig.java:1385)
      at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1193)
      at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:783)
      at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:307)
      at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:95)
      at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
      at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5213)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
      ... 6 more
  
  Sep 25, 2016 5:52:04 PM org.apache.catalina.core.ContainerBase startInternal
  SEVERE: A child container failed during start
  java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
      at java.util.concurrent.FutureTask.report(Unknown Source)
      at java.util.concurrent.FutureTask.get(Unknown Source)
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:915)
      at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
      at org.apache.catalina.core.StandardService.startInternal(StandardService.java:441)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
      at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:787)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
      at org.apache.catalina.startup.Catalina.start(Catalina.java:629)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
      at java.lang.reflect.Method.invoke(Unknown Source)
      at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:351)
      at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:485)
  Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost]]
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:162)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1407)
      at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1397)
      at java.util.concurrent.FutureTask.run(Unknown Source)
      at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
      at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
      at java.lang.Thread.run(Unknown Source)
  Caused by: org.apache.catalina.LifecycleException: A child container failed during start
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:923)
      at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:871)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
      ... 6 more
  
  Sep 25, 2016 5:52:04 PM org.apache.catalina.startup.Catalina start
  SEVERE: The required Server component failed to start so Tomcat is unable to start.
  org.apache.catalina.LifecycleException: Failed to start component [StandardServer[8005]]
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:162)
      at org.apache.catalina.startup.Catalina.start(Catalina.java:629)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
      at java.lang.reflect.Method.invoke(Unknown Source)
      at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:351)
      at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:485)
  Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardService[Catalina]]
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:162)
      at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:787)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
      ... 7 more
  Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina]]
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:162)
      at org.apache.catalina.core.StandardService.startInternal(StandardService.java:441)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
      ... 9 more
  Caused by: org.apache.catalina.LifecycleException: A child container failed during start
      at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:923)
      at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:262)
      at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
      ... 11 more
  
  Sep 25, 2016 5:52:04 PM org.apache.coyote.AbstractProtocol pause
  INFO: Pausing ProtocolHandler ["http-nio-8080"]
  Sep 25, 2016 5:52:04 PM org.apache.coyote.AbstractProtocol pause
  INFO: Pausing ProtocolHandler ["ajp-nio-8009"]
  Sep 25, 2016 5:52:04 PM org.apache.catalina.core.StandardService stopInternal
  INFO: Stopping service Catalina
  Sep 25, 2016 5:52:04 PM org.apache.coyote.AbstractProtocol destroy
  INFO: Destroying ProtocolHandler ["http-nio-8080"]
  Sep 25, 2016 5:52:04 PM org.apache.coyote.AbstractProtocol destroy
  SEVERE: Failed to destroy end point associated with ProtocolHandler ["http-nio-8080"]
  java.lang.NullPointerException
      at org.apache.tomcat.util.net.NioEndpoint.releaseCaches(NioEndpoint.java:316)
      at org.apache.tomcat.util.net.NioEndpoint.unbind(NioEndpoint.java:492)
      at org.apache.tomcat.util.net.AbstractEndpoint.destroy(AbstractEndpoint.java:821)
      at org.apache.coyote.AbstractProtocol.destroy(AbstractProtocol.java:551)
      at org.apache.catalina.connector.Connector.destroyInternal(Connector.java:1023)
      at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:292)
      at org.apache.catalina.core.StandardService.destroyInternal(StandardService.java:589)
      at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:292)
      at org.apache.catalina.core.StandardServer.destroyInternal(StandardServer.java:877)
      at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:292)
      at org.apache.catalina.startup.Catalina.start(Catalina.java:633)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
      at java.lang.reflect.Method.invoke(Unknown Source)
      at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:351)
      at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:485)
  
  Sep 25, 2016 5:52:04 PM org.apache.coyote.AbstractProtocol destroy
  INFO: Destroying ProtocolHandler ["ajp-nio-8009"]
  Sep 25, 2016 5:52:04 PM org.apache.coyote.AbstractProtocol destroy
  SEVERE: Failed to destroy end point associated with ProtocolHandler ["ajp-nio-8009"]
  java.lang.NullPointerException
      at org.apache.tomcat.util.net.NioEndpoint.releaseCaches(NioEndpoint.java:316)
      at org.apache.tomcat.util.net.NioEndpoint.unbind(NioEndpoint.java:492)
      at org.apache.tomcat.util.net.AbstractEndpoint.destroy(AbstractEndpoint.java:821)
      at org.apache.coyote.AbstractProtocol.destroy(AbstractProtocol.java:551)
      at org.apache.catalina.connector.Connector.destroyInternal(Connector.java:1023)
      at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:292)
      at org.apache.catalina.core.StandardService.destroyInternal(StandardService.java:589)
      at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:292)
      at org.apache.catalina.core.StandardServer.destroyInternal(StandardServer.java:877)
      at org.apache.catalina.util.LifecycleBase.destroy(LifecycleBase.java:292)
      at org.apache.catalina.startup.Catalina.start(Catalina.java:633)
      at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
      at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
      at java.lang.reflect.Method.invoke(Unknown Source)
      at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:351)
      at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:485)
  </code></pre>