Interpreting Design Patterns----Proxy patterns (proxy pattern)

One of those things about buying a computer

I have been using the desktop, can always feel inconvenient, especially carry, take a tenant after the move to say, the cost of a lot of strength. For a variety of reasons there is a desire to change the idea of a notebook. 5.1 Holiday and a good friend to the computer city to stroll a circle, a computer city will see: "HP Notebook XX General agent, IBM notebook monopoly, XX computer yy general agent ...".

See a lot of home sales shop, give me the deepest impression is everywhere is XX brand computer monopoly and agents, on the same floor I saw the same brand has 6 agents sales shops. Oh, it seems that we buy a computer directly to find sales agents can be, there is no need to find manufacturers, manufacturers to produce a computer is to sell products to the market, and agents in the process to replace the manufacturer to sell products. This reminds me of the object-oriented design pattern-proxy model.

Ii. talking about proxy model

1, the agent mode of intent:

Provides a proxy for other objects to control access to this object.

As a computer sales agent, he is responsible for providing an agent to control how computers are sold to computer manufacturers.

2, Agent mode UML diagram (the following figure selected from http://www.dofactory.com/):