Java design pattern--Behavioral mode--strategy mode

Policy mode:

　　

1 Policy Mode2 Overview3 define a series of algorithms, encapsulate them one by one, and make them interchangeable with each other. This mode allows the algorithm to be independent of the customers who use it. 4  5 Applicability61many of the related classes are simply behavior-specific. Policy provides a way to configure a class with one behavior in multiple behaviors. 7 82. You need to use different variants of an algorithm. 9 Ten3the algorithm uses data that the customer should not know about. You can use the policy mode to avoid exposing complex, algorithmic-related data structures.  One  A4. A class defines a variety of behaviors, and these behaviors appear as multiple conditional statements in the operation of this class.  - The related conditional branches are moved into their respective strategy classes in place of these conditional statements.  -   the   - participants -1. Strategy - defines the public interface for all supported algorithms. The context uses this interface to invoke an algorithm defined by a concretestrategy.


 +  -2. Concretestrategy + a specific algorithm is implemented with strategy interface.  A  at3. Context - configured with a Concretestrategy object.  - maintains a reference to the Strategy object.  -You can define an interface to let stategy access its data.


Test class:

1  Public classTest {2     3      Public Static voidMain (string[] args) {4Context CTX =NewContext (NewStrategyimpla ());5 Ctx.domethod ();6         7CTX =NewContext (NewSTRATEGYIMPLB ());8 Ctx.domethod ();9         TenCTX =NewContext (NewSTRATEGYIMPLC ()); One Ctx.domethod (); A     } -}

1  Public classContext {2 3 strategy stra;4     5      PublicContext (Strategy stra) {6          This. Stra =Stra;7     }8     9      Public voidDomethod () {Ten Stra.method (); One     } A}

1  Public Abstract class Strategy {23      Public Abstract void method (); 4 }

1  Public class extends Strategy {23      Public void method () {4         System.out.println ("This is the first implementation"); 5     }6 }

1  Public class extends Strategy {23      Public void method () {4         System.out.println ("This is a second implementation"); 5     }6 }

1  Public class extends Strategy {23      Public void method () {4         System.out.println ("This is a third implementation"); 5     }6 }

The great God wrote the code is not the same

Java design pattern--Behavioral mode--strategy mode