OpenMRS Version Error

gistfile1.txt

The following error occurred at startup:
OpenMRS requires Java 6, but is running under 1.8.0_20
org.openmrs.api.APIException: OpenMRS requires Java 6, but is running under 1.8.0_20
	at org.openmrs.util.OpenmrsUtil.validateJavaVersion(OpenmrsUtil.java:1203)
	at org.openmrs.web.Listener.contextInitialized(Listener.java:121)
	at org.eclipse.jetty.server.handler.ContextHandler.callContextInitialized(ContextHandler.java:787)
	at org.eclipse.jetty.servlet.ServletContextHandler.callContextInitialized(ServletContextHandler.java:434)
	at org.eclipse.jetty.server.handler.ContextHandler.startContext(ContextHandler.java:779)
	at org.eclipse.jetty.servlet.ServletContextHandler.startContext(ServletContextHandler.java:284)
	at org.eclipse.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1322)
	at org.eclipse.jetty.server.handler.ContextHandler.doStart(ContextHandler.java:731)
	at org.eclipse.jetty.webapp.WebAppContext.doStart(WebAppContext.java:490)
	at org.eclipse.jetty.maven.plugin.JettyWebAppContext.doStart(JettyWebAppContext.java:280)
	at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:69)
	at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:108)
	at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:90)
	at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:58)
	at org.eclipse.jetty.server.handler.ContextHandlerCollection.doStart(ContextHandlerCollection.java:175)
	at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:69)
	at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:108)
	at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:90)
	at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:58)
	at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:69)
	at org.eclipse.jetty.util.component.ContainerLifeCycle.start(ContainerLifeCycle.java:108)
	at org.eclipse.jetty.server.Server.start(Server.java:342)
	at org.eclipse.jetty.util.component.ContainerLifeCycle.doStart(ContainerLifeCycle.java:90)
	at org.eclipse.jetty.server.handler.AbstractHandler.doStart(AbstractHandler.java:58)
	at org.eclipse.jetty.server.Server.doStart(Server.java:290)
	at org.eclipse.jetty.maven.plugin.JettyServer.doStart(JettyServer.java:68)
	at org.eclipse.jetty.util.component.AbstractLifeCycle.start(AbstractLifeCycle.java:69)
	at org.eclipse.jetty.maven.plugin.AbstractJettyMojo.startJetty(AbstractJettyMojo.java:556)
	at org.eclipse.jetty.maven.plugin.AbstractJettyMojo.execute(AbstractJettyMojo.java:352)
	at org.eclipse.jetty.maven.plugin.JettyRunWarMojo.execute(JettyRunWarMojo.java:69)
	at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:106)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59)
	at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183)
	at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161)
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:318)
	at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:153)
	at org.apache.maven.cli.MavenCli.execute(MavenCli.java:555)
	at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:214)
	at org.apache.maven.cli.MavenCli.main(MavenCli.java:158)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:483)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:290)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:230)
	at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:414)
	at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:357)