Design pattern Learning (V) Adapter mode

Structural mode:

---core role: to achieve loose coupling from the structure of the program, so that the whole class structure can be enlarged to solve the larger problem

---categories:

Adapter mode, proxy mode, bridge mode, decoration mode, combo mode, appearance mode, enjoy meta mode

Adapter Mode: Principle:

--Convert a class interface into another interface that the customer wants.

Advantages:

Adapter mode makes it possible for classes to work together because they are incompatible with the interface

Roles in the pattern:

• Destination interface (target): the interface that the customer expects. The target can be a specific or abstract class, or it can be an interface
• Classes that need to be adapted (Adaptee): Classes or adapter classes that need to be adapted
• Adapter (Adapter): By wrapping an object that needs to be adapted. Convert the original interface into a target interface

Implementation mode: 1: Class Adapter:

 Package Com.lp.adpater;  Public class extends Implements Target  {    @Override    publicvoid  handlereq () {        super. Request ();    }}

Class Adapter

2: Object Adapter:

 Package Com.lp.adpater;  Public class adaptee {    publicvoid  request () {        System.out.println ("ability to complete customer needs" );    }}

classes that need to be adapted

 Package Com.lp.adpater;  Public Interface Target {    void  handlereq ();}

Target Interface

 Package Com.lp.adpater;  Public class Implements Target  {    private  adaptee adaptee;    @Override    publicvoid  handlereq () {        adaptee.request ();    }      Public Adapter (adaptee adaptee) {        Super();         this. adaptee = adaptee;    }    }

Adapter

 PackageCom.lp.adpater;//Client Class//equivalent to a laptop computer with only USB interface Public classClient { Public voidtest1 (Target t) {t.handlereq (); }     Public Static voidMain (string[] arg) {Client C=NewClient (); Adaptee a=Newadaptee (); Target T=NewAdapter (a);    C.test1 (t); }    }

Client

Work in the scene:

-often used to retrofit and upgrade old systems

-If we don't need to maintain the system after development, many models are unnecessary, but unfortunately, the cost of maintaining a system is often several times that of developing a system.

The learning scenario is used in adapter mode:

--Java.io.InputStremReader (InputStream)

--Java.io.OutputStremReader (OutputStream)

Design pattern Learning (V) Adapter mode