CODEWITHSUNDEEP
javaserializationdeserialization
huican
huican

Reputation: 505

Read serialized java object from disk with newer class?

Just a simple question:

If I saved a java object on disk, but after that I added some more data member (String type), can new class read those old java object back with those new String member as null?

Upvotes: 0

Views: 269

Answers (1)

Christian Hujer
Christian Hujer

Reputation: 17945

This is possible, but for that you need to manage compatibility actively. You need to ensure that the new class has the same serialVersionUID value as the old class. This private static final long serialVersionUID field can be auto-generated - or manually assigned. See http://docs.oracle.com/javase/8/docs/api/java/io/Serializable.html

If you already have a serialVersionUID, the new field will be null.

If you don't, you want to create one and use the same value as the auto-generated value of the old class. That's what the tool serialver is for.

Upvotes: 1

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