product.java

用struts2＋jpa来实现了对音乐

package net.jeffrey.hibernate;

import java.io.Serializable;
import java.util.HashSet;
import java.util.Set;
import javax.persistence.Entity;
import javax.persistence.JoinColumn;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.ManyToOne;
import net.jeffrey.hibernate.history.Historizable;

/**
 * 商品类
 * @author jeffrey
 */
@Entity
public class Product extends AbstractEntity implements Serializable, Historizable {
    private String name;
    @ManyToOne
    private Category category;
    @ManyToMany
    @JoinTable(
        name = "product_tag",
        joinColumns = {@JoinColumn(name = "product_id")},
        inverseJoinColumns = {@JoinColumn(name = "tag_id")}
    )
    private Set<Tag> tags = new HashSet<Tag>();
    
    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Category getCategory() {
        return category;
    }

    public void setCategory(Category category) {
        if (this.category != null) {
            this.category.getProducts().remove(this);
        }
        this.category = category;
        if (category != null) {
            category.getProducts().add(this);
        }
    }

    public Set<Tag> getTags() {
        return tags;
    }

    public void setTags(Set<Tag> tags) {
        this.tags = tags;
    }
    
    public void addTag(Tag tag) {
        if (tag != null) {
            this.tags.add(tag);
            tag.getProducts().add(this);
        }
    }
    
    public void removeTag(Tag tag) {
        if (tag != null) {
            this.tags.remove(tag);
            tag.getProducts().remove(this);
        }
    }
    
    @Override
    public String toString() {
        return "Product[" + id + "," + name + "]";
    }
    
    @Override
    public boolean equals(Object obj) {
        if (obj == null) {
            return false;
        }
        if (getClass() != obj.getClass()) {
            return false;
        }
        final Product other = (Product) obj;
        return getId().equals(other.getId());
    }

    @Override
    public int hashCode() {
        int hash = 7;
        return hash = 47 * hash + id;
    }
}