commons-chain

StrategyPattern

package patterns;

import java.util.ArrayList;
import java.util.List;

/**
 * @author [email protected]
 * @date 11/8/19
 * @description patterns
 */
public class StrategyPattern {
    public static void main(String[] args) {
        House house = new iGlassHouse();
        house.build();
        System.out.println("*************");

        house = new iWoodenHouse();
        house.build();
    }
}

interface Strategy{
    void execute();
}

class GlassWindowBuilder implements Strategy{

    @Override
    public void execute() {
        System.out.println("建玻璃窗户");
    }
}

class WoodWindowBuilder implements Strategy{

    @Override
    public void execute() {
        System.out.println("建木窗户");
    }
}

class GlassPillarBuilder implements Strategy{

    @Override
    public void execute() {
        System.out.println("建玻璃支柱");
    }
}

class WoodPillarBuilder implements Strategy{

    @Override
    public void execute() {
        System.out.println("建木支柱");
    }
}

abstract class House {

    // 有顺序的策略
    private List<Strategy> builders = new ArrayList<>();

    // template method, final so subclasses can't override
    abstract void init();

    void addBuilder(Strategy builder){
        builders.add(builder);
    }

    void build(){
        this.init();
        for(Strategy builder: builders){
            builder.execute();
        }
    }
}

class iWoodenHouse extends House {
    @Override
    void init() {
        this.addBuilder(new WoodPillarBuilder());
        this.addBuilder(new WoodWindowBuilder());
    }
}

class iGlassHouse extends House {
    @Override
    void init() {
        this.addBuilder(new GlassPillarBuilder());
        this.addBuilder(new GlassWindowBuilder());
    }
}