Design Patterns | Proxy

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1. References
2. Example
   • The Subject
   • The Real Subject
   • The Proxy
   • A simple class to test the Proxy design pattern

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1. References
   • Definition: (source: http://en.wikipedia.org/wiki/Proxy_pattern)
     
     A proxy, in its most general form, is a class functioning as an interface to something else.
     The proxy could interface to anything: a network connection, a large object in memory, a file, or some other resource that is expensive or impossible to duplicate.
     
     
   • Class diagram: (source: http://en.wikipedia.org/wiki/Proxy_pattern)
     
     
2. Example
   • The Subject:
     
     public interface Logger { void log(); }
     
   • The Real Subject:
     
     public class FileLogger implements Logger { public void log() { System.out.println("FileLogger-log"); } }
     
   • The Proxy:
     
     public class ProxyFileLogger implements Logger { private final Logger logger = new FileLogger(); public void log() { logger.log(); } }
     
   • A simple class to test the Proxy design pattern:
     
     public class ProxyPatternTest { public static void main(String[] args) { // create the proxy Logger logger = new ProxyFileLogger(); // call method logger.log(); } }