Can't start Liferay tomcat server - apache

Question

I'm trying to start Liferay tomcat server on Ubuntu 14.04.
To install Liferay 6.1.1, I used the following tutoriel:
http://www.youtube.com/watch?v=3uLWkqCg6kg
However, I couldn't start the tomcat server. I got ERROR:
10:19:23,067 ERROR [http-bio-8080-exec-3][MainServlet:1224] com.liferay.portal.kernel.events.ActionException: java.lang.NullPointerException
.
.
.
Caused by: java.lang.NullPointerException
at com.liferay.portal.model.impl.LayoutSetImpl.getColorScheme(LayoutSetImpl.java:50)
at com.liferay.portal.model.impl.LayoutImpl.getColorScheme(LayoutImpl.java:241)
at com.liferay.portal.events.ThemeServicePreAction.servicePre(ThemeServicePreAction.java:80)
at com.liferay.portal.events.ThemeServicePreAction.run(ThemeServicePreAction.java:44)
... 111 more
juil. 06, 2014 10:19:23 AM org.apache.catalina.core.ApplicationDispatcher invoke
GRAVE: "Servlet.service()" pour la servlet jsp a lancé une exception
org.apache.jasper.JasperException: Impossible de compiler la classe pour la JSP:
An error occurred at line: 1 in the generated java file
The type java.util.Map$Entry cannot be resolved. It is indirectly referenced from required .class files
An error occurred at line: 176 in the generated java file
The import java.util.Arrays cannot be resolved
Stacktrace:
at org.apache.jasper.compiler.DefaultErrorHandler.javacError(DefaultErrorHandler.java:102)
.
.
.
I don't know what's wrong.

Answer 1

Even if you want to run your portlet on Java 8.
Follow steps
Steps to fix:-
1.Go to Lib folder of Liferay Tomcat .
2.Replace :- ecj-3.7.2.jar with ecj-4.4.2.
3.Restart the Server.

Answer 2

First of all, the tutorial says that you should install OpenJDK. That is not true, Liferay works well only on Sun/Oracle Java. My guess is that this is the cause of the problem.
There are a lot of tutorials about how to install Oracle Java on Ubuntu, check this for example.
Secondly this tutorial says about 6.1.2 version and you are trying to install 6.1.1. That's also quite important as Java 7 is supported exclusively since 6.1.2 (check James Falkner's blog post). For 6.1.1 you should use Java 6.
Hope that helps,
KG