Service層學習總結：
	1、在包下新增Service包
	2、在包類新增CategoryService介面，在介面中新增需要用到的方法。
	3、新增CategoryServiceImpl類，並實現CategoryService的方法，在類上添加註解@Service；注入repository.
	4、測試類：在測試類中注入CategoryServiceImpl，寫Service中的各個方法測試
	//Service介面
	package com.dairy.sell.service;

	import com.dairy.sell.dataobject.ProductCategory;

	import java.util.List;

	public interface CategoryService {
	    ProductCategory findOne(Integer categoryId);
	    List<ProductCategory> findAll();
	    List<ProductCategory> findByCategoryTypeIn(List<Integer> categoryTypeId);
	    ProductCategory save(ProductCategory productCategory);

	}

	//Service層實現
	package com.dairy.sell.service.impl;

	import com.dairy.sell.dataobject.ProductCategory;
	import com.dairy.sell.repository.ProductCategoryRepository;
	import com.dairy.sell.service.CategoryService;
	import org.springframework.beans.factory.annotation.Autowired;
	import org.springframework.stereotype.Service;

	import java.util.List;
	@Service
	public class CategoryServiceImpl implements CategoryService {
	    @Autowired
	    private ProductCategoryRepository productCategoryRepository;
	    @Override
	    public ProductCategory findOne(Integer categoryId) {
	        return productCategoryRepository.findByCategoryId(categoryId);

	    }

	    @Override
	    public List<ProductCategory> findAll() {
	        return productCategoryRepository.findAll();
	    }

	    @Override
	    public List<ProductCategory> findByCategoryTypeIn(List<Integer> categoryTypeId) {
	        return productCategoryRepository.findByCategoryTypeIn(categoryTypeId);
	    }

	    @Override
	    public ProductCategory save(ProductCategory productCategory) {
	        return productCategoryRepository.save(productCategory);
	    }
	}

	//測試類

	package com.dairy.sell.service.impl;

	import com.dairy.sell.dataobject.ProductCategory;
	import org.junit.Assert;
	import org.junit.Test;
	import org.junit.runner.RunWith;
	import org.springframework.beans.factory.annotation.Autowired;
	import org.springframework.boot.test.context.SpringBootTest;
	import org.springframework.test.annotation.Rollback;
	import org.springframework.test.context.junit4.SpringRunner;
	import org.springframework.transaction.annotation.Transactional;

	import java.util.Arrays;
	import java.util.Date;
	import java.util.List;

	import static org.junit.Assert.*;

	@RunWith(SpringRunner.class)
	@SpringBootTest
	public class CategoryServiceImplTest {

	    @Autowired
	    private CategoryServiceImpl categoryService;


	    @Test
	    public void findOne() {
	        ProductCategory productCategory = categoryService.findOne(1);
	        Assert.assertNotEquals(new Integer(2), productCategory.getCategoryId());
	    }

	    @Test
	    public void findAll() {
	        List<ProductCategory> productCategory = categoryService.findAll();
	        Assert.assertNotEquals(0, productCategory.size());


	    }

	    @Test
	    public void findByCategoryTypeIn() {
	        List<Integer> list = Arrays.asList(1, 2, 3, 4);
	        List<ProductCategory> productCategory = categoryService.findByCategoryTypeIn(list);
	        Assert.assertNotEquals(0, productCategory.size());
	    }

	    @Test
	    @Transactional
	    @Rollback(true)
	    public void save() {
	        ProductCategory productCategory = new ProductCategory(new Date(), new Date(), "鞋子", new Integer(02));

	        ProductCategory productCategory1 = categoryService.save(productCategory);
	        Assert.assertNotNull(productCategory1);
	    }
	}