像Java SE一样编写Java EE（ddd探索）

public interface TreeProduct {
    /**
     * 展示所有产品
     * @return
     */
    List<TreeProduct> allProducts();

    /**
     * 增加一个产品
     * @param product
     * @return
     */
    boolean addProduct(TreeProduct product);

    /**
     * 增加一组产品
     * @param products
     * @return
     */
    boolean addProducts(List<TreeProduct> products);

    /**
     * 移除产品
     * @param product
     * @return
     */
    boolean removeProduct(TreeProduct product);

    /**
     * 保存数据进数据库
     * @param product
     * @return
     */
    int save(TreeProduct product);
}

@Mapper
public interface ProductDao {
    @Insert("insert into type_product (id,name) values (#{id},#{name})")
    int saveType(TypeProduct type);
    @Insert("insert into product (id,name,model,price) values (#{id},#{name},#{model},#{price})")
    int saveProduct(Product product);
    @Update("update type_product t set t.parent_id=#{sourceId} where t.id=#{id}")
    int addType(Param param);
    @Update("update product p set p.type_id=#{sourceId} where p.id=#{id}")
    int addProduct(Param param);
    @Delete("delete from type_product where id=#{id}")
    int removeType(Long id);
    @Delete("delete from product where id=#{id}")
    int removeProduct(Long id);
}

public class SpringBootUtil {
    private static ApplicationContext applicationContext = null;

    public static void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
        if(SpringBootUtil.applicationContext == null){
            SpringBootUtil.applicationContext  = applicationContext;
        }
    }

    //获取applicationContext
    public static ApplicationContext getApplicationContext() {
        return applicationContext;
    }

    //通过name获取 Bean.
    public static Object getBean(String name){
        return getApplicationContext().getBean(name);

    }

    //通过class获取Bean.
    public static <T> T getBean(Class<T> clazz){
        return getApplicationContext().getBean(clazz);
    }

    //通过name,以及Clazz返回指定的Bean
    public static <T> T getBean(String name,Class<T> clazz){
        return getApplicationContext().getBean(name, clazz);
    }
}

@EnableTransactionManagement
@SpringBootApplication
public class ProductApplication {

   public static void main(String[] args) {
      ApplicationContext applicationContext = SpringApplication.run(ProductApplication.class, args);
      SpringBootUtil.setApplicationContext(applicationContext);
   }

}

@NoArgsConstructor
@ToString
public class TypeProduct implements TreeProduct {
    @Getter
    @Setter
    private Long id;
    @Getter
    @Setter
    private String name;
    //下级产品列表
    @Getter
    private List<TreeProduct> treeProducts = new CopyOnWriteArrayList<>();
    public TypeProduct(Long id,String name) {
        this.id = id;
        this.name = name;
    }
    @Override
    public List<TreeProduct> allProducts() {
        return this.treeProducts;
    }

    @Override
    public boolean addProduct(TreeProduct product) {
        ProductDao productDao = SpringBootUtil.getBean(ProductDao.class);
        Param param = null;
        if (product instanceof TypeProduct) {
            param = new Param(this.id,((TypeProduct) product).getId());
            productDao.addType(param);
        }else if (product instanceof Product) {
            param = new Param(this.id,((Product) product).getId());
            productDao.addProduct(param);
        }
        return treeProducts.add(product);
    }

    @Override
    public boolean removeProduct(TreeProduct product) {
        ProductDao productDao = SpringBootUtil.getBean(ProductDao.class);
        if (product instanceof TypeProduct) {
            productDao.removeType(((TypeProduct) product).getId());
        }else if (product instanceof Product) {
            productDao.removeProduct(((Product) product).getId());
        }
        return treeProducts.remove(product);
    }

    @Override
    public boolean addProducts(List<TreeProduct> products) {
        for (TreeProduct product:products) {
            this.addProduct(product);
        }
        return true;
    }

    @Override
    public int save(TreeProduct product) {
        ProductDao productDao = SpringBootUtil.getBean(ProductDao.class);
        if (product instanceof TypeProduct) {
            return productDao.saveType((TypeProduct) product);
        }
        return 0;
    }
}

@Data
@AllArgsConstructor
@NoArgsConstructor
@ToString
public class Product implements TreeProduct {
    private Long id;
    private String name;
    private String model;
    private BigDecimal price;

    @Override
    public List<TreeProduct> allProducts() {
        return Arrays.asList(this);
    }

    @Override
    public boolean addProduct(TreeProduct product) {
        throw new RuntimeException("不支持此方法");
    }

    @Override
    public boolean removeProduct(TreeProduct product) {
        throw new RuntimeException("不支持此方法");
    }

    @Override
    public boolean addProducts(List<TreeProduct> products) {
        throw new RuntimeException("不支持此方法");
    }

    @Override
    public int save(TreeProduct product) {
        ProductDao productDao = SpringBootUtil.getBean(ProductDao.class);
        if (product instanceof Product) {
            return productDao.saveProduct((Product) product);
        }
        return 0;
    }
}

public class ProductFactory {
    public static TreeProduct createType(Long id,String name) {
        TreeProduct product = new TypeProduct(id,name);
        product.save(product);
        return product;
    }
    public static TreeProduct createProduct(Long id, String name, String model, BigDecimal price) {
        TreeProduct product = new Product(id,name,model,price);
        product.save(product);
        return product;
    }
}

@RestController
public class ProductController {
    @Autowired
    private IdService idService;

    @Transactional
    @GetMapping("/showall")
    public TreeProduct showAll() {
        //生产一个根目录
        TreeProduct root = ProductFactory.createType(idService.genId(),"根目录");
        //生产一个可乐的产品类型
        TreeProduct type1 = ProductFactory.createType(idService.genId(),"可乐");
        //生产一个咖啡的产品类型
        TreeProduct type2 = ProductFactory.createType(idService.genId(),"咖啡");
        //产品类型列表
        List<TreeProduct> types1 = new ArrayList<>();
        types1.add(type1);
        types1.add(type2);
        //生产一个可口可乐的产品
        TreeProduct product1 = ProductFactory.createProduct(idService.genId(),"可口可乐","500ml",new BigDecimal(3));
        //生产一个雀巢咖啡的产品
        TreeProduct product2 = ProductFactory.createProduct(idService.genId(),"雀巢咖啡","600ml",new BigDecimal(6));
        //将产品类型列表添加到根目录中
        root.addProducts(types1);
        //将可口可乐放入可乐类型中
        type1.addProduct(product1);
        //将雀巢咖啡放入咖啡类型中
        type2.addProduct(product2);
        //返回整个产品类型和产品
        return root;
    }
}