35 lines
1.2 KiB
Markdown
35 lines
1.2 KiB
Markdown
---
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layout: pattern
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title: Memento
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folder: memento
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permalink: /patterns/memento/
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categories: Behavioral
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tags:
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- Gang of Four
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---
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## Also known as
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Token
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## Intent
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Without violating encapsulation, capture and externalize an
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object's internal state so that the object can be restored to this state later.
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## Class diagram
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## Applicability
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Use the Memento pattern when
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* a snapshot of an object's state must be saved so that it can be restored to that state later, and
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* a direct interface to obtaining the state would expose implementation details and break the object's encapsulation
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## Real world examples
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* [java.util.Date](http://docs.oracle.com/javase/8/docs/api/java/util/Date.html)
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## Credits
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* [Design Patterns: Elements of Reusable Object-Oriented Software](https://www.amazon.com/gp/product/0201633612/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0201633612&linkCode=as2&tag=javadesignpat-20&linkId=675d49790ce11db99d90bde47f1aeb59)
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* [Head First Design Patterns: A Brain-Friendly Guide](https://www.amazon.com/gp/product/0596007124/ref=as_li_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=0596007124&linkCode=as2&tag=javadesignpat-20&linkId=6b8b6eea86021af6c8e3cd3fc382cb5b)
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