2015-08-13 23:54:40 +02:00
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---
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layout: pattern
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title: Lazy Loading
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folder: lazy-loading
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2015-08-15 18:03:05 +02:00
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permalink: /patterns/lazy-loading/
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2019-12-13 21:09:28 +02:00
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categories: Idiom
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2021-05-19 10:49:05 -06:00
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language: en
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2015-12-28 15:52:44 +02:00
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tags:
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2015-12-28 16:07:43 +02:00
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- Performance
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2015-08-13 23:54:40 +02:00
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---
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2016-01-03 21:14:30 +01:00
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## Intent
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Lazy loading is a design pattern commonly used to defer
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2015-08-13 23:54:40 +02:00
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initialization of an object until the point at which it is needed. It can
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contribute to efficiency in the program's operation if properly and
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appropriately used.
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2019-12-07 20:01:13 +02:00
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## Class diagram
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2015-08-13 23:54:40 +02:00
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2016-01-03 21:14:30 +01:00
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## Applicability
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Use the Lazy Loading idiom when
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* eager loading is expensive or the object to be loaded might not be needed at all
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2016-01-03 21:14:30 +01:00
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## Real world examples
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2015-08-13 23:54:40 +02:00
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2015-08-15 18:03:05 +02:00
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* JPA annotations @OneToOne, @OneToMany, @ManyToOne, @ManyToMany and fetch = FetchType.LAZY
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2016-01-27 12:55:59 +05:30
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2016-04-16 08:52:16 +03:00
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## Credits
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2016-04-15 08:38:08 +03:00
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2020-07-06 13:31:07 +03:00
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* [J2EE Design Patterns](https://www.amazon.com/gp/product/0596004273/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596004273&linkCode=as2&tag=javadesignpat-20&linkId=48d37c67fb3d845b802fa9b619ad8f31)
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2020-07-07 21:19:14 +03:00
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* [Patterns of Enterprise Application Architecture](https://www.amazon.com/gp/product/0321127420/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0321127420&linkCode=as2&tag=javadesignpat-20&linkId=d9f7d37b032ca6e96253562d075fcc4a)
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