package net.jeffrey.hibernate;import java.io.Serializable;import java.util.ArrayList;import java.util.List;import javax.persistence.Entity;import javax.persistence.OneToMany;import net.jeffrey.hibernate.history.Historizable;import org.hibernate.annotations.Cascade;/** * 商品分類 * @author jeffrey */@Entitypublic class Category extends AbstractEntity implements Serializable, Historizable {        private String name;        @OneToMany(mappedBy = "category")    // 定義級聯，必須使用hibernate的級聯annotation，JPA的Cascade不起作用    @Cascade(org.hibernate.annotations.CascadeType.ALL)    private List<Product> products = new ArrayList<Product>();    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public List<Product> getProducts() {        return products;    }    public void setProducts(List<Product> products) {        this.products = products;    }        /* Helper方法，在添加商品的同時建立雙方的關聯關系 */    public void addProduct(Product p) {        if (p != null) {            p.setCategory(this);            this.products.add(p);        }    }        /* Helper方法，在刪除商品的同時解除雙方的關聯關系 */    public void removeProduct(Product p) {        if (p != null) {            p.setCategory(null);            this.products.remove(p);        }    }    @Override    public String toString() {        return "Category[" + id + "," + name + "]";    }    @Override    public boolean equals(Object obj) {        if (obj == null) {            return false;        }        if (getClass() != obj.getClass()) {            return false;        }        final Category other = (Category) obj;        if (this.id != other.id && (this.id == null || !this.id.equals(other.id))) {            return false;        }        return true;    }    @Override    public int hashCode() {        int hash = 3;        return hash = 47 * hash + id;    }}