33 lines
1.1 KiB
Markdown
33 lines
1.1 KiB
Markdown
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---
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layout: pattern
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title: Proxy
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folder: proxy
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categories: pattern_cat
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tags: pattern_tag
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---
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**Intent:** Provide a surrogate or placeholder for another object to control
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access to it.
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**Applicability:** Proxy is applicable whenever there is a need for a more
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versatile or sophisticated reference to an object than a simple pointer. Here
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are several common situations in which the Proxy pattern is applicable
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* a remote proxy provides a local representative for an object in a different address space.
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* a virtual proxy creates expensive objects on demand.
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* a protection proxy controls access to the original object. Protection proxies are useful when objects should have different access rights.
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**Typical Use Case:**
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* control access to another object
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* lazy initialization
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* implement logging
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* facilitate network connection
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* to count references to an object
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**Real world examples:**
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* [java.lang.reflect.Proxy](http://docs.oracle.com/javase/8/docs/api/java/lang/reflect/Proxy.html)
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* [Apache Commons Proxy](https://commons.apache.org/proper/commons-proxy/)
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