[ERROR] Failed to execute goal org.codehaus.mojo:apt-maven-plugin:1.0-alpha-5:process (default) on project jenkins-core: Unable to locate the apt compiler in:
[ERROR] /usr/lib/jvm/java-8-jdk/jre/../lib/tools.jar
[ERROR] Please ensure you are using JDK 1.5 or above and
[ERROR] not a JRE (the com.sun.tools.apt.Main class is required).
[ERROR] In most cases you can change the location of your Java
[ERROR] installation by setting the JAVA_HOME environment variable.
[ERROR] -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal org.codehaus.mojo:apt-maven-plugin:1.0-alpha-5:process (default) on project jenkins-core: Unable to locate the apt compiler in:
  /usr/lib/jvm/java-8-jdk/jre/../lib/tools.jar
Please ensure you are using JDK 1.5 or above and
not a JRE (the com.sun.tools.apt.Main class is required).
In most cases you can change the location of your Java
installation by setting the JAVA_HOME environment variable.
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:212)
	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:116)
	at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80)
	at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51)
	at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:128)
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307)
	at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193)
	at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106)
	at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863)
	at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288)
	at org.apache.maven.cli.MavenCli.main(MavenCli.java:199)
	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:498)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289)
	at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229)
	at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415)
	at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356)
Caused by: org.apache.maven.plugin.MojoExecutionException: Unable to locate the apt compiler in:
  /usr/lib/jvm/java-8-jdk/jre/../lib/tools.jar
Please ensure you are using JDK 1.5 or above and
not a JRE (the com.sun.tools.apt.Main class is required).
In most cases you can change the location of your Java
installation by setting the JAVA_HOME environment variable.
	at org.codehaus.mojo.apt.AptUtils.getAptClass(AptUtils.java:220)
	at org.codehaus.mojo.apt.AptUtils.invoke(AptUtils.java:76)
	at org.codehaus.mojo.apt.AbstractAptMojo.executeApt(AbstractAptMojo.java:389)
	at org.codehaus.mojo.apt.AbstractAptMojo.executeImpl(AbstractAptMojo.java:277)
	at org.codehaus.mojo.apt.AbstractAptMojo.execute(AbstractAptMojo.java:254)
	at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:134)
	at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:207)
	... 20 more