适配器模式

package com.example.xpj.adapters;

import com.example.xpj.DPConstants;

public class DPFoodFactory {
    // 食物生产者，每种类型只能生产自己擅长的食物
    public interface DPFood<T> {
        T produceFood();
    }

    public static class DPIntFood implements DPFood<Integer> {
        @Override
        public Integer produceFood() {
            return 2333;
        }
    }

    public static class DPLongFood implements DPFood<Long> {
        @Override
        public Long produceFood() {
            return 6666L;
        }
    }

    // adapter 的 接口，有两个泛型一个输入一个输出
    public interface DPAdapter<T, R> {
        R adapt(T t);
    }

    public static class DPInt2StringAdapter implements DPAdapter<Integer, String> {
        @Override
        public String adapt(Integer t) {
            return t.toString() + " im from Int. ";
        }
    }

    public static class DPLong2StringAdapter implements DPAdapter<Long, String> {
        @Override
        public String adapt(Long t) {
            return t.toString() + " im From Long. ";
        }
    }

    // 这里用户只能吃 String 的食物
    public static class DPAdapterUser {
        public void feedMe(String food) {
            DPConstants.PRTMsg("yes this food is i like! " + food + " thank you!!");
        }
    }

    public void testAdapter() {
        DPAdapterUser user = new DPAdapterUser();
        // 调用对应的 adapter 去转换为用户能够消化的食物
        user.feedMe(new DPInt2StringAdapter().adapt(new DPIntFood().produceFood()));
        user.feedMe(new DPLong2StringAdapter().adapt(new DPLongFood().produceFood()));
    }
}