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NOTICE: This version of the NSF Unidata web site (archive.unidata.ucar.edu) is no longer being updated.
Current content can be found at unidata.ucar.edu.
To learn about what's going on, see About the Archive Site.
Hi Nils:Default Java serialization has serious problems. See chapter 11 of "Effective Java" for details. Early versions of Netcdf-Java had lots of serialization, but I have removed it mostly.
If you want to do serialization, I would create specialized objects that take the original object as an argument, and transfer the contents.
Recently Ive been using Google's "protocol buffer" library to do the encoding, and I like that approach. Fast, and the serialized objects are readable from other languages besides java.
May seem like more work, but in the long run, IMO default java serialization is not a good persistence solution except in certain limited cases.
John On 11/13/2012 2:13 AM, Nils Hoffmann wrote:
Hi netcdf-java developers, I recently had the requirement of serializing/deserializing a ucar.ma2.Array instance for local client-side caching and was wondering why the current implementation (4.2.32) does not implement java.io.Serializable or java.io.Externalizable? Are there any particular reasons for this, or am I overlooking something? In order to check whether any severe problems would wait down the road, I created a delegate for ucar.ma2.Array and wrote an associated unit test, showing that it is possible to successfully serialize and deserialize arbitrary arrays. I would however prefer to be able to extend ucar.ma2.Array directly, which is currently not possible unless I create the new class within the ucar.ma2 namespace. This is due to three methods in ucar.ma2.Array that are using default visibility (abstract Array createView(Index index), abstract void copyFrom1DJavaArray(IndexIterator iter, Object javaArray), and abstract void copyTo1DJavaArray(IndexIterator iter, Object javaArray)). Their visibility effectively disallows extension of ucar.ma2.Array from outside the ucar.ma2 package. Would it be possible to set the visibility of these methods to public in the netcdf-java api without other negative side effects or would anyone propose a different approach? Maybe someone else has experience with Array serialization and would be interested in sharing or providing me some further pointers? I would greatly appreciate any help on this. Sincerely, Nils
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