productDao类中的save方法一定要static化？ 代码如下：

package com.vae.dao;

import com.vae.entity.Product;

public class ProductDao {

public static  void save(Product product){

System.out.println("Dao中的方法被执行");

}

}

package com.vae.service;

import com.vae.dao.ProductDao;

import com.vae.entity.Product;

public class ProductService {

private ProductDao productDao;

public void setProductDao(ProductDao productDao) {

this.productDao = productDao;

}

public void save(Product product){

System.out.println("Service中的方法被执行");

ProductDao.save(product);

}

}