java.lang.SecurityException: sealing violation:

Question

I am using GWT for my Java application. When I try to run it as web application, I get the following error:

java.lang.SecurityException: sealing violation: can't seal package org.mortbay.util: already loaded

I can't find anything helpful if I Google for the error. Am I missing something?

Solution 1

It means the package is sealed and you tried to load another jar also containing the package.

See Sealing Packages within a JAR File.

Solution 2

Your current exception shows that you are using Jetty in your project. Possible problem might be that you have this jar available twice in your classpath.

Comments

[Sandro]

org.mortbay.util is a package of jetty, so you can look, if you have multiple jars of jetty in your classpath. As you are using GWT, I think it could include jetty by itself, so try removing all jetty jars from your classpath.

[Dime]

Better find the source of a duplicated jar. What will you do if one of your components gets updated? You will get a mess at the end.