Java Learning notes-design pattern nine. Builder mode

Builder mode, which separates the construction of a complex object from its representation, so that the same build process can create different representations.

Product class:

1 Package Cn.happy.design_pattern._09builder;2 3 import java.util.ArrayList;4 import java.util.List;5 6  Public classProduct {7 8list<string> parts =NewArraylist<>();9     Ten      Public voidAdd (String part) { One Parts.add (part); A     } -      -      Public voidShow () { theSystem. out. println ("Create product ..."); -          for(String item:parts) { -System. out. println (item); -         } +     } -}

Builder class:

1 Package Cn.happy.design_pattern._09builder;2 3  Public Abstract classBuilder {4 5      Public Abstract voidBuildparta ();6      Public Abstract voidBUILDPARTB ();7      Public AbstractProduct GetResult ();8}

Builder sub-class:

1 Package Cn.happy.design_pattern._09builder;2 3  Public classConcreteBuilder1 extends Builder {4 5     PrivateProduct Product =NewProduct ();6 @Override7      Public voidBuildparta () {8Product.add ("Part A");9 Ten     } One  A @Override -      Public voidBUILDPARTB () { -Product.add ("Part B"); the  -     } -  - @Override +      PublicProduct GetResult () { -         //TODO auto-generated Method Stub +         returnproduct; A     } at  - } -  -  Public classConcreteBuilder2 extends Builder { -  -     PrivateProduct Product =NewProduct (); in @Override -      Public voidBuildparta () { toProduct.add ("Part x"); +  -     } the  * @Override $      Public voidBUILDPARTB () {Panax NotoginsengProduct.add ("Part y"); -  the     } +  A @Override the      PublicProduct GetResult () { +         //TODO auto-generated Method Stub -         returnproduct; $     } $  -}

Director class:

1 Package Cn.happy.design_pattern._09builder; 2 3  Public class Director {45      Public void Construct (Builder builder) {6        Builder. Buildparta (); 7         Builder. BUILDPARTB (); 8     }9 }

Test class:

1 Package Cn.happy.design_pattern._09builder;2 3  Public classMmain {4      Public Static voidMain (string[] args) {5Director Director =NewDirector ();6Builder B1 =NewConcreteBuilder1 ();7Builder B2 =NewConcreteBuilder2 ();8 Director. Construct (B1);9 B1. GetResult (). Show ();Ten Director. Construct (B2); One B2. GetResult (). Show (); A     } -}

Java Learning Note-design pattern nine. Builder mode