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Java Google App Engine: what does @Persistent (valueStrategy = IdGeneratorStrategy.IDENTITY) do?

I was just starting to learn server / database stuff in Java, and I was wondering what the @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) piece of code @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY) means / does. I am using google app engine

Thanks!

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That Java annotation defines the strategy that the annotated object will use.

This means that, for example, if you have a class Employee , it will be permanent, and the way that its primary key is generated will have a mechanism called IDENTITY , which automatically creates the following value for you,

This whole part of the API is called the Java Persistence API.

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Source: https://habr.com/ru/post/1313792/

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