【Hibernate 一对多】

OneToMany

public class OneToMany {

    @Test
    public void testAdd1() {
        SessionFactory sessionFactory = null;
        Session session = null;
        Transaction tx = null;
        try {
            sessionFactory = HibernateUtils.getSessionFactory();
            session = sessionFactory.openSession();
            tx = session.beginTransaction();

            Customer customer = new Customer();
            customer.setCustName("顾客1");
            customer.setCustLevel("vip");
            customer.setCustSource("网络");
            customer.setCustPhone("138");
            customer.setCustMobile("999");

            LinkMan linkman = new LinkMan();
            linkman.setLkm_name("联系人1");
            linkman.setLkm_gender("男");
            linkman.setLkm_phone("109");

            customer.getSetLinkMan().add(linkman);
            linkman.setCustomer(customer);

            session.save(customer);
            // session.save(linkman);
            tx.commit();
            System.out.println("====================");
        } catch (Exception e) {
            e.printStackTrace();
            tx.rollback();
        } finally {
            if (session != null)
                session.close();
            if (sessionFactory != null)
                sessionFactory.close();
        }
    }

    @Test
    public void testDelete1() {
        SessionFactory sessionFactory = null;
        Session session = null;
        Transaction tx = null;
        try {
            sessionFactory = HibernateUtils.getSessionFactory();
            session = sessionFactory.openSession();
            tx = session.beginTransaction();

            Customer customer = session.get(Customer.class, 1);
            if (null != customer) {
                session.delete(customer);
            }
            tx.commit();
            System.out.println("====================");
        } catch (Exception e) {
            e.printStackTrace();
            tx.rollback();
        } finally {
            if (session != null)
                session.close();
            if (sessionFactory != null)
                sessionFactory.close();
        }
    }
}

 Customer

public class Customer {
    //客户id
    private Integer cid;
    //客户名称
    private String custName;
    //客户级别
    private String custLevel;
    //客户来源
    private String custSource;
    //联系电话
    private String custPhone;
    //手机
    private String custMobile;

    //在客户实体类里面表示多个联系人，一个客户有多个联系人
    //hibernate要求使用集合表示多的数据，使用set集合
    private Set<LinkMan> setLinkMan = new HashSet<LinkMan>();

    public Set<LinkMan> getSetLinkMan() {
        return setLinkMan;
    }

    public void setSetLinkMan(Set<LinkMan> setLinkMan) {
        this.setLinkMan = setLinkMan;
    }

    public Integer getCid() {
        return cid;
    }

    public void setCid(Integer cid) {
        this.cid = cid;
    }

    public String getCustName() {
        return custName;
    }

    public void setCustName(String custName) {
        this.custName = custName;
    }

    public String getCustLevel() {
        return custLevel;
    }

    public void setCustLevel(String custLevel) {
        this.custLevel = custLevel;
    }

    public String getCustSource() {
        return custSource;
    }

    public void setCustSource(String custSource) {
        this.custSource = custSource;
    }

    public String getCustPhone() {
        return custPhone;
    }

    public void setCustPhone(String custPhone) {
        this.custPhone = custPhone;
    }

    public String getCustMobile() {
        return custMobile;
    }

    public void setCustMobile(String custMobile) {
        this.custMobile = custMobile;
    }
}
View Code

Customer.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
    <!-- 1 配置类和表对应
        class标签
        name属性：实体类全路径
        table属性：数据库表名称
    -->
    <class name="k.entity.Customer" table="t_customer">
        <id name="cid" column="cid">
            <generator class="native"></generator>
        </id>
        <property name="custName" column="custName"></property>
        <property name="custLevel" column="custLevel"></property>
        <property name="custSource" column="custSource"></property>
        <property name="custPhone" column="custPhone"></property>
        <property name="custMobile" column="custMobile"></property>

        <!-- 在客户映射文件中，表示所有联系人
            使用set标签表示所有联系人
            set标签里面有name属性：
                 属性值写在客户实体类里面表示联系人的set集合名称

             inverse属性默认值：false不放弃关系维护
                            true表示放弃关系维护
        -->
        <set name="setLinkMan" inverse="true" cascade="save-update,delete">
            <!-- 一对多建表，有外键
                hibernate机制：双向维护外键，在一和多那一方都配置外键
                column属性值：外键名称
             -->
            <key column="clid"></key>
            <!-- 客户所有的联系人，class里面写联系人实体类全路径 -->
            <one-to-many class="k.entity.LinkMan"/>
        </set>
    </class>
</hibernate-mapping>

LinkMan

public class LinkMan {
    private Integer lkm_id; // 联系人编号(主键)
    private String lkm_name;// 联系人姓名
    private String lkm_gender;// 联系人性别
    private String lkm_phone;// 联系人办公电话

    // 在联系人实体类里面表示所属客户,一个联系人只能属于一个客户
    private Customer customer;
    public Customer getCustomer() {
        return customer;
    }
    public void setCustomer(Customer customer) {
        this.customer = customer;
    }

    public Integer getLkm_id() {
        return lkm_id;
    }
    public void setLkm_id(Integer lkm_id) {
        this.lkm_id = lkm_id;
    }
    public String getLkm_name() {
        return lkm_name;
    }
    public void setLkm_name(String lkm_name) {
        this.lkm_name = lkm_name;
    }
    public String getLkm_gender() {
        return lkm_gender;
    }
    public void setLkm_gender(String lkm_gender) {
        this.lkm_gender = lkm_gender;
    }
    public String getLkm_phone() {
        return lkm_phone;
    }
    public void setLkm_phone(String lkm_phone) {
        this.lkm_phone = lkm_phone;
    }
}
View Code

LinkMan.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
    <!-- 1 配置类和表对应
        class标签
        name属性：实体类全路径
        table属性：数据库表名称
    -->
    <class name="k.entity.LinkMan" table="t_linkman">
        <id name="lkm_id" column="lkm_id">
            <generator class="native"></generator>
        </id>
        <property name="lkm_name" column="lkm_name"></property>
        <property name="lkm_gender" column="lkm_gender"></property>
        <property name="lkm_phone" column="lkm_phone"></property>

        <!-- 表示联系人所属客户
            name属性：因为在联系人实体类使用customer对象表示，写customer名称
            class属性：customer全路径
            column属性：外键名称
        -->
        <many-to-one name="customer" class="k.entity.Customer" column="clid"></many-to-one>
    </class>
</hibernate-mapping>

HibernateUtils

public class HibernateUtils {

    static Configuration cfg = null;
    static SessionFactory sessionFactory = null;
    //静态代码块实现
    static {
        //加载核心配置文件
        cfg = new Configuration();
        cfg.configure();
        sessionFactory = cfg.buildSessionFactory();
    }

    //提供返回与本地线程帮的session的方法
    public static Session getSessionobject() {
        return sessionFactory.getCurrentSession();
    }

    //提供方法返回sessionFactory
    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }

    public static void main(String[] args) {

    }
}

hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
    "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <!-- 第一部分： 配置数据库信息 必须的 -->
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.url">jdbc:mysql:///hibernate_day01</property>
        <property name="hibernate.connection.useUnicode">true</property>
        <property name="hibernate.connection.characterEncoding">UTF-8</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">root3306</property>
        
        <!-- 第二部分： 配置hibernate信息  可选的-->
        <!-- 输出底层sql语句 -->
        <property name="hibernate.show_sql">true</property>
        <!-- 输出底层sql语句格式 -->
        <property name="hibernate.format_sql">true</property>
        <!-- hibernate帮创建表，需要配置之后 
            update: 如果已经有表，更新，如果没有，创建
        -->
        <property name="hibernate.hbm2ddl.auto">update</property>
        <!-- 配置数据库方言
            在mysql里面实现分页 关键字 limit，只能使用mysql里面
            在oracle数据库，实现分页rownum
            让hibernate框架识别不同数据库的自己特有的语句
         -->
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
        
        <!-- 第三部分： 把映射文件放到核心配置文件中 必须的-->
        <!--<mapping resource="k/entity/User.hbm.xml"/>-->
        <mapping resource="k/entity/Customer.hbm.xml"/>
        <mapping resource="k/entity/LinkMan.hbm.xml"/>
    </session-factory>
</hibernate-configuration>
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原文地址：https://www.cnblogs.com/kikyoqiang/p/12292611.html