NoClassDefFoundError: ConcurrentHashMap

  • Anonymous - 2012-07-25

    Hi all,

    I am trying to maintain some old code that I wrote back in 2008 and import the current 1.0.3 ical4j version.

    At runtime it fails with:

    Exception in thread "main" java.lang.NoClassDefFoundError: edu/emory/mathcs/backport/java/util/concurrent/ConcurrentHashMap
        at net.fortuna.ical4j.util.CompatibilityHints.<clinit>(
        at net.fortuna.ical4j.model.Iso8601.<init>(
        at net.fortuna.ical4j.model.Date.<init>(
        at net.fortuna.ical4j.model.DateTime.<init>(
        at jdiary.Main.main(
    Caused by: java.lang.ClassNotFoundException:
        at Method)
        at java.lang.ClassLoader.loadClass(
        at sun.misc.Launcher$AppClassLoader.loadClass(
        at java.lang.ClassLoader.loadClass(
        ... 5 more

    I can't remember how I built this before, but now I am using Eclipse.

    Can anyone help me understand what I need to do?

    Many thanks,
    - jon.

  • JonEK

    JonEK - 2012-07-25

    Hi all,
    sorry, I was being a bit thick! I have it now.
    I need to add the other external JARs to my build/run classpath.

    Thanks for reading this far,
    - jon.


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