Servlet not working :Error 500

i'm new to tomcat and i try access to my project located at http://ift.tt/1JZ5d2C , I get the following error...

javax.servlet.ServletException: "Servlet.init ()" for the EB-api servlet threw an exception
org.apache.catalina.authenticator.AuthenticatorBase.invoke (AuthenticatorBase.java:501)
org.apache.catalina.valves.ErrorReportValve.invoke (ErrorReportValve.java:98)
org.apache.catalina.valves.AccessLogValve.invoke (AccessLogValve.java:950)
org.apache.catalina.connector.CoyoteAdapter.service (CoyoteAdapter.java:408)
org.apache.coyote.http11.AbstractHttp11Processor.process (AbstractHttp11Processor.java:1040)
org.apache.coyote.AbstractProtocol $ AbstractConnectionHandler.process (AbstractProtocol.java:607)
org.apache.tomcat.util.net.JIoEndpoint $ SocketProcessor.run (JIoEndpoint.java:313)
java.util.concurrent.ThreadPoolExecutor $ Worker.runTask (ThreadPoolExecutor.java:886)
java.util.concurrent.ThreadPoolExecutor $ Worker.run (ThreadPoolExecutor.java:908)
java.lang.Thread.run (Thread.java:619)

mother cause

java.lang.UnsupportedClassVersionError: telecom / SudParis / eu / paas / core / server / resources / manager / application / ApplicationManagerRessource: Unsupported major.minor Version 51.0 (Unable to load class telecom.sudparis.eu.paas.core.server.ressources .manager.application.ApplicationManagerRessource)
org.apache.catalina.loader.WebappClassLoader.findClassInternal (WebappClassLoader.java:2948)
org.apache.catalina.loader.WebappClassLoader.findClass (WebappClassLoader.java:1208)
org.apache.catalina.loader.WebappClassLoader.loadClass (WebappClassLoader.java:1688)
org.apache.catalina.loader.WebappClassLoader.loadClass (WebappClassLoader.java:1569)
java.lang.Class.forName0 (Native Method)
java.lang.Class.forName (Class.java:247)
com.sun.jersey.core.reflection.ReflectionHelper.classForNameWithException (ReflectionHelper.java:238)
com.sun.jersey.spi.scanning.AnnotationScannerListener$AnnotatedClassVisitor.getClassForName(AnnotationScannerListener.java:214)
com.sun.jersey.spi.scanning.AnnotationScannerListener$AnnotatedClassVisitor.visitEnd(AnnotationScannerListener.java:183)
org.objectweb.asm.ClassReader.accept (Unknown Source)
org.objectweb.asm.ClassReader.accept (Unknown Source)
com.sun.jersey.spi.scanning.AnnotationScannerListener.onProcess (AnnotationScannerListener.java:133)
com.sun.jersey.core.spi.scanning.uri.FileSchemeScanner $ 1.f (FileSchemeScanner.java:86)
com.sun.jersey.core.util.Closing.f (Closing.java:71)
com.sun.jersey.core.spi.scanning.uri.FileSchemeScanner.scanDirectory (FileSchemeScanner.java:83)
com.sun.jersey.core.spi.scanning.uri.FileSchemeScanner.scanDirectory (FileSchemeScanner.java:80)
com.sun.jersey.core.spi.scanning.uri.FileSchemeScanner.scan (FileSchemeScanner.java:71)
com.sun.jersey.core.spi.scanning.PackageNamesScanner.scan (PackageNamesScanner.java:225)
com.sun.jersey.core.spi.scanning.PackageNamesScanner.scan (PackageNamesScanner.java:141)
com.sun.jersey.api.core.ScanningResourceConfig.init (ScanningResourceConfig.java:80)
com.sun.jersey.api.core.PackagesResourceConfig.init (PackagesResourceConfig.java:104)
com.sun.jersey.api.core.PackagesResourceConfig. <init> (PackagesResourceConfig.java:78)
com.sun.jersey.api.core.PackagesResourceConfig. <init> (PackagesResourceConfig.java:89)
com.sun.jersey.spi.container.servlet.WebComponent.createResourceConfig (WebComponent.java:700)
com.sun.jersey.spi.container.servlet.WebComponent.createResourceConfig (WebComponent.java:678)
com.sun.jersey.spi.container.servlet.WebComponent.init (WebComponent.java:203)
com.sun.jersey.spi.container.servlet.ServletContainer.init (ServletContainer.java:373)
com.sun.jersey.spi.container.servlet.ServletContainer.init (ServletContainer.java:556)
javax.servlet.GenericServlet.init (GenericServlet.java:158)
org.apache.catalina.authenticator.AuthenticatorBase.invoke (AuthenticatorBase.java:501)
org.apache.catalina.valves.ErrorReportValve.invoke (ErrorReportValve.java:98)
org.apache.catalina.valves.AccessLogValve.invoke (AccessLogValve.java:950)
org.apache.catalina.connector.CoyoteAdapter.service (CoyoteAdapter.java:408)
org.apache.coyote.http11.AbstractHttp11Processor.process (AbstractHttp11Processor.java:1040)
org.apache.coyote.AbstractProtocol $ AbstractConnectionHandler.process (AbstractProtocol.java:607)
org.apache.tomcat.util.net.JIoEndpoint $ SocketProcessor.run (JIoEndpoint.java:313)
java.util.concurrent.ThreadPoolExecutor $ Worker.runTask (ThreadPoolExecutor.java:886)
java.util.concurrent.ThreadPoolExecutor $ Worker.run (ThreadPoolExecutor.java:908)
java.lang.Thread.run (Thread.java:619)

I've got a web.xml file for this project...

web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://ift.tt/ra1lAU" xmlns="http://ift.tt/nSRXKP" xmlns:web="http://ift.tt/nSRXKP" xsi:schemaLocation="http://ift.tt/nSRXKP http://ift.tt/LU8AHS" id="WebApp_ID" version="2.5">
  <display-name>EB-PaaS REST API</display-name>
  <servlet>
    <servlet-name>EB-api</servlet-name>
    <servlet-class>com.sun.jersey.spi.container.servlet.ServletContainer</servlet-class>
    <init-param>
      <param-name>com.sun.jersey.config.property.packages</param-name>
      <param-value>telecom.sudparis.eu.paas.core.server.ressources.manager</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup>
  </servlet>
  <servlet-mapping>
    <servlet-name>EB-api</servlet-name>
    <url-pattern>/rest/*</url-pattern>
  </servlet-mapping>
  <welcome-file-list>
    <welcome-file>index.html</welcome-file>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

Please can anybody help me as soon as possible , i extremely need it for my project...