Can a non-serialized Java object be stored in mySQL BLob column?

1) Can they still be written to a mySQL BLOB column?

Yes, but you'll need to implement a serialisation algorithm to generate the bytes. Also, you will need to be sure you can access all the required internal state.

2) Is there any other way of persisting them outside of my JVM?

Take a look at XStream

Well, they don't have to be serializable in terms of "Java's default binary serialization scheme" but they have to be serializable somehow, by definition: you've got to have some way of extracting the data into a byte array, and then reconstituting it later from that array.

How you do that is up to you - there are lots of serialization frameworks/protocols/etc around.

1. They can, but not automatically. You'll have to come up with your own code to construct a binary representation of your object, persist the binary data to your database, and then reconstruct the object when you pull the data out of the database.

2. Yes, but again it will not be automatic. You'll have to come up with your own binary representation of the object, decide how you want to store it, and then reconstruct the object when you want to read it.

Serializable doesn't do anything in itself, it's just a way to hint that a class can be serializable. Some tools requires the presence of the interface while some does not.

I haven't looked into storing java objects as mySQL BLOB, but if serializable java objects can be then I see no reason why it wouldn't be possible.

2) Is there any other way of persisting them outside of my JVM?

There are many ways to persist objects outside JVM. Store it to disk, ftp, network storage, etc., and there exist just as many tools for storing in various format (such as XML, etc.).