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hibernate双向多对多映射关系的配置

1、实体类

package com.yl.bean;

import java.io.Serializable;
import java.util.Set;

/**
 * 商品实体类
 */
public class Goods implements Serializable {
    private Integer id;//商品id
    private String goodsName;//商品名
    private Double price;//商品价格
    private String remark;//备注
    private Set<GoodsOrder> orderSet;//商品所属订单

    public Goods() {
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getGoodsName() {
        return goodsName;
    }

    public void setGoodsName(String goodsName) {
        this.goodsName = goodsName;
    }

    public Double getPrice() {
        return price;
    }

    public void setPrice(Double price) {
        this.price = price;
    }

    public String getRemark() {
        return remark;
    }

    public void setRemark(String remark) {
        this.remark = remark;
    }

    public Set<GoodsOrder> getOrderSet() {
        return orderSet;
    }

    public void setOrderSet(Set<GoodsOrder> orderSet) {
        this.orderSet = orderSet;
    }

    @Override
    public String toString() {
        return "Goods{" +
                "goods_id=" + id +
                ", goodsName=‘" + goodsName + ‘\‘‘ +
                ", price=" + price +
                ", remark=‘" + remark + ‘\‘‘ +
                ", orderSet=" + orderSet +
                ‘}‘;
    }
}

package com.yl.bean;

import java.io.Serializable;
import java.util.Set;

/**
 * 商品订单实体类
 */
public class GoodsOrder implements Serializable {
    private Integer id;//订单id
    private String orderNo;//订单编号
    private Double price;//订单价格
    private Set<Goods> goodsSet;//订单包含的商品

    public GoodsOrder() {
    }

    public Integer getId() {
        return id;
    }

    public void setId(Integer id) {
        this.id = id;
    }

    public String getOrderNo() {
        return orderNo;
    }

    public void setOrderNo(String orderNo) {
        this.orderNo = orderNo;
    }

    public Double getPrice() {
        return price;
    }

    public void setPrice(Double price) {
        this.price = price;
    }

    public Set<Goods> getGoodsSet() {
        return goodsSet;
    }

    public void setGoodsSet(Set<Goods> goodsSet) {
        this.goodsSet = goodsSet;
    }

    @Override
    public String toString() {
        return "GoodsOrder{" +
                "id=" + id +
                ", orderNo=‘" + orderNo + ‘\‘‘ +
                ", price=" + price +
                ", goodsSet=" + goodsSet +
                ‘}‘;
    }
}

2、全局配置文件（hibernate.cfg.xml）

<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <!--数据源配置-->
        <property name="hibernate.connection.driver_class">com.mysql.cj.jdbc.Driver</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hibernate?characterEncoding=utf8&amp;serverTimezone=GMT%2B8</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">123456</property>
        <!--显示sql-->
        <property name="hibernate.show_sql">true</property>
        <!--自动创建表-->
        <property name="hibernate.hbm2ddl.auto">update</property>
        <!--指定映射配置文件的位置-->
        <mapping resource="com/yl/bean/Goods.hbm.xml"></mapping>
        <mapping resource="com/yl/bean/GoodsOrder.hbm.xml"></mapping>
</session-factory>
</hibernate-configuration>

3、商品类映射配置文件（Goods.hbm.xml）

<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
    <!--配置Goods类-->
    <class name="com.yl.bean.Goods" table="t_goods">
        <!--主键-->
        <id name="id" column="id" type="java.lang.Integer">
            <generator class="identity"></generator>
        </id>

        <property name="goodsName" column="goodsName" type="java.lang.String"></property>
        <property name="price" column="price" type="java.lang.Double"></property>
        <property name="remark" column="remark"></property>

        <!--多对多关系映射-->
        <set name="orderSet" table="t_goods_order">
            <key column="goods_id"></key>
            <many-to-many class="com.yl.bean.GoodsOrder" column="order_id"></many-to-many>
        </set>
    </class>
</hibernate-mapping>

4、订单类映射配置文件（GoodsOrder.hbm.xml）

<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
    <!--配置GoodsOrder类-->
    <class name="com.yl.bean.GoodsOrder" table="t_order">
        <!--主键-->
        <id name="id" column="id" type="java.lang.Integer">
            <generator class="identity"></generator>
        </id>

        <property name="orderNo" column="orderNo" type="java.lang.String"></property>
        <property name="price" column="price" type="java.lang.Double"></property>

        <!--多对多关系映射-->
        <set name="goodsSet" table="t_goods_order">
            <key column="order_id"></key>
            <many-to-many class="com.yl.bean.Goods" column="goods_id"></many-to-many>
        </set>
    </class>
</hibernate-mapping>

5、测试

 @Test
    public void addTest(){
        Session session= HibernateUtils.getSession();

        Goods goods=new Goods();
        goods.setGoodsName("小米");
        goods.setPrice(3999.0);
        goods.setRemark("为发烧而生");

        Goods goods1=new Goods();
        goods1.setRemark("中华有为");
        goods1.setPrice(3999.0);
        goods1.setGoodsName("华为");

        GoodsOrder order=new GoodsOrder();
        order.setOrderNo("001");
        order.setPrice(7998.0);

        GoodsOrder order1=new GoodsOrder();
        order1.setOrderNo("002");
        order1.setPrice(7998.0);

        Set<GoodsOrder> orderSet=new HashSet<>();
        orderSet.add(order);
        orderSet.add(order1);
        goods.setOrderSet(orderSet);
        goods1.setOrderSet(orderSet);

      /*  Set<GoodsOrder> orderSet1=new HashSet<>();
        orderSet1.add(order1);
        goods1.setOrderSet(orderSet1);*/

        Set<Goods> goodsSet=new HashSet<>();
        goodsSet.add(goods);
        goodsSet.add(goods1);
//注意这里，只需要一方关联即可（上面已经关联了，所以不需要再次添加商品集合），两方关联会造成主键重复，报错
//        order.setGoodsSet(goodsSet);
//        order1.setGoodsSet(goodsSet);

        Transaction transaction=session.beginTransaction();

        session.save(goods);
        session.save(goods1);
        session.save(order);
        session.save(order1);

        transaction.commit();
        session.close();

    }

hibernate双向多对多映射关系的配置

标签：实体类   报错   多对多关系映射   商品   vat   public   rac   drive   ati   

原文地址：https://www.cnblogs.com/Y-wee/p/13804845.html