Closure 閉包 封裝特定的業務功能

員工類

    //員工類
    static class Staff {
        private String name;
        private double money;

        @Override
        public String toString() {
            return "staff{" +
                    "name='" + name + '\'' +
                    ", money=" + money +
                    '}';
        }

        public Staff() {

        }

        public Staff(String name, int money) {
            this.name = name;
            this.money = money;
        }

        public String getName() {
            return name;
        }

        public void setName(String name) {
            this.name = name;
        }

        public double getMoney() {
            return money;
        }

        public void setMoney(double money) {
            this.money = money;
        }
    }
 

Closure使用如下

    public static void baseic() {
        //建立容器
        List<Staff> list = new ArrayList<>();
        list.add(new Staff("zs", 2000));
        list.add(new Staff("lisi", 1000));
        list.add(new Staff("www", 3000));

        Closure<Staff> closure = new Closure<Staff>() {
            @Override
            public void execute(Staff s) {
                //工資全部上漲1.2
                s.setMoney(s.getMoney() * 1.2);
            }
        };
        //工具類  方法已經過時 IterableUtils.forEach取代
        //CollectionUtils.forAllDo(list, closure);

        IterableUtils.forEach(list, closure);

        //迴圈輸出
        list.stream().forEach(System.out::println);


    }
 

 IfClosure的簡單使用

建立商品實體

package com.hp.common;

/**
 * 商品實體類
 */
public class Goods {
    private String name;

    private double price;
    //是否打折
    private boolean discount;


    public Goods(String name, double price, boolean discount) {
        this.name = name;
        this.price = price;
        this.discount = discount;
    }

    public Goods(){}

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    public boolean isDiscount() {
        return discount;
    }

    public void setDiscount(boolean discount) {
        this.discount = discount;
    }

    @Override
    public String toString() {
        return "Goods{" +
                "name='" + name + '\'' +
                ", price=" + price +
                ", discount=" + discount +
                '}';
    }
}
 

 IfClosure的簡單使用使用如下

    //如果商品 打折 則打九折  否則滿100 減20
    public static void IfClosure() {

        List<Goods> list = new ArrayList<>();
        list.add(new Goods("javase", 120, true));
        list.add(new Goods("c++", 100, false));
        list.add(new Goods("c#", 80, false));

        //滿100 -20
        Closure<Goods> closure = new Closure<Goods>() {
            @Override
            public void execute(Goods input) {
                if (input.getPrice() >= 100) {
                    input.setPrice(input.getPrice() - 20);
                }
            }
        };
        //打九折
        Closure<Goods> closure1 = new Closure<Goods>() {
            @Override
            public void execute(Goods input) {
                if (input.isDiscount()) {
                    input.setPrice(input.getPrice() * 0.9);
                }
            }
        };


        Predicate<Goods> predicate = new Predicate<Goods>() {
            @Override
            public boolean evaluate(Goods goods) {
                return goods.isDiscount();
            }
        };
        //二選一的操作   IfClosure.ifClosure(斷言,為true執行,為false執行)
        Closure<Goods> ifClosure = IfClosure.ifClosure(predicate, closure1, closure);
        //
        IterableUtils.forEach(list, ifClosure);

        //迴圈輸出
        list.stream().forEach(System.out::println);


    }

WhileClosure使用如下

  //員工的工資 最低不超過1w 如果超過什麼也不變
    public static void minimumWage() {
        List<Staff> list = new ArrayList<>();
        list.add(new Staff("張三", 10000));
        list.add(new Staff("李四", 8000));
        list.add(new Staff("王五", 5000));
        //業務邏輯
        Closure<Staff> closure = new Closure<Staff>() {
            @Override
            public void execute(Staff input) {
                input.setMoney(input.getMoney() * 1.2);
            }
        };

        Predicate<Staff> predicate = new Predicate<Staff>() {
            @Override
            public boolean evaluate(Staff staff) {
                return staff.getMoney() < 10000;
            }
        };
        // dolop 為false  先執行,後判斷     為true 先判斷後執行
        Closure<Staff> staffClosure = WhileClosure.whileClosure(predicate, closure, false);


        IterableUtils.forEach(list,staffClosure);

        //迴圈
        list.stream().forEach(System.out::println);


    }

ChainedClosure使用如下

 //如果商品打折   則打九折  九折後超過100  -20  滿百-20
    public static void checkClosure(){
        List<Goods> list = new ArrayList<>();
        list.add(new Goods("javase", 120, true));
        list.add(new Goods("c++", 100, false));
        list.add(new Goods("c#", 80, false));


        //打折商品 打九折
        Closure<Goods> closure=new Closure<Goods>() {
            @Override
            public void execute(Goods input) {
                if (input.isDiscount()) {
                    input.setPrice(input.getPrice() * 0.9);
                }
            }
        };

        //滿一百減20
        Closure<Goods> closure1=new Closure<Goods>() {
            @Override
            public void execute(Goods input) {
                if (input.getPrice()>=100) {
                    input.setPrice(input.getPrice() -20);
                }
            }
        };

        Closure<Goods> goodsClosure = ChainedClosure.chainedClosure(closure, closure1);


        IterableUtils.forEach(list,goodsClosure);

        list.forEach(System.out::println);


    }