Cross-application Concurrent Hashmap

Question

I am trying to share a concurrent hashmap between applications on a Glassfish (v2) server.

First question, is it at all possible? Secondly, if it is, any suggestions?

What I am trying to achieve is a memory store (cache?) which can be quickly referenced and updated by different components on the same instance. Implementation is a standard key/value set.

Thanks in advance!

score 2 · Answer 1 · answered Dec 09 '11 at 14:54

2

Sounds like you want a distributed cache. I'd recommend looking at Ehcache and this documentation on cache topologies.

answered Dec 09 '11 at 14:54

Greg Case

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score 1 · Answer 2 · answered Dec 09 '11 at 17:22

1

I think maybe you can take a look at Hazelcast project.

answered Dec 09 '11 at 17:22

roy

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score 1 · Answer 3 · edited May 23 '17 at 12:24

1

I also recommend Hazelcast. It is deadly simple to use and here some comparison

edited May 23 '17 at 12:24

Community

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answered Dec 12 '11 at 13:55

enesness

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score 0 · Answer 4 · answered Dec 09 '11 at 14:52

0

What worked for me a long time ago was placing the collection as a singleton in a library which is shared across all applications. This way the library is loaded once and all application use that copy (and its collection)

answered Dec 09 '11 at 14:52

Peter Lawrey

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score 0 · Answer 5 · answered Dec 09 '11 at 14:55

If you are talking about 2 "applications" in the same JVM then it should certainly be possible. If they are in the same ClassLoader then you should be able to do:

public class MapHolder {
    private static final ConcurrentHashMap<String, String> cache =
        new ConcurrentHashMap<String, String>();

    public static ConcurrentHashMap<String, String> getCacheSingleTon() {
        return cache;
    }
}

Then each of your modules can say something like:

public class Foo {
    private ConcurrentHashMap<String, String> cache =
        MapHolder.getCacheSingleTon();
}

This said, I'm not experienced with Glassfish. They may already have caching modules that are available.

Cross-application Concurrent Hashmap

5 Answers5