[JAVA] abstract Factory Pattern

user gets the object using only abstract class and interface By using the Factory Pattern, the user does not need to be aware of the various objects required for the composition of the target object and their combinations. </ Font>

Below is the sample code of the abstract Factory Pattern.

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The class structure is as follows

class	Explanation
abstract factory.class	Define abstract create method
samFactoryA.class	Extend the factory Generate and combine the parts classes required to compose the target
samFactoryB.class	Same as above
interface face1 interface face2	Interface for parts
parts1.class ～ parts4.class	Parts class required for the composition of the target product
user(Main.class)	Check the operation

User Includes the meaning that other developers use this pattern

The sample code below uses two factories Because abstract Factory Pattern makes it easy to create multiple factories There is a feature that improves the convenience of the user

`factory.class`


abstract class factory{
  String msg;
  int    len;

  factory(String msg){
    this.msg = msg;
    len =msg.length();
  }

  abstract String create();
}

`samFactoryA.class`


class samFactoryA extends factory{
  samFactoryA(String msg){super(msg);}

  String create(){
    String partsA = new partsA().s;
    String partsB = new partsB().s;
    return partsA+super.msg+partsB;
}}

`samFactoryB.class`


class samFactoryB extends factory{
  samFactoryB(String msg){super(msg);}
  
  String create(){
    String partsA = new partsA().s;
    String partsB = new partsB().s;
    String partsC = new partsC().s;
    String partsD = new partsD().s;
    return partsA+partsC + super.msg + partsD+partsB;
}}

`interface_face1`


interface face1{}
class partsA implements face1{String s="<<< ";}
class partsB implements face1{String s=" >>>";}

interface face2{}
class partsC implements face2{String s="[[[ ";}
class partsD implements face2{String s=" ]]]";}

`user(Main.class)`


public static void main(String[] args){
  factory f1 = new samFactoryA("Hello java");
    System.out.println(f1.create());
  
  factory f2 = new samFactoryB("HELLO JAVA");
    System.out.println(f2.create());
}}