使用XML Hibernate多对一映射 Hibernate多对一|Hibernate

本文概述

1）一对一映射的持久类
2）持久类的映射文件
3）配置文件
4）用于存储和获取数据的用户类

在多对一映射中, 各种属性只能称为一个属性。
在此示例中, 每个员工只有一个公司地址, 而一个地址属于许多员工。在这里, 我们将使用XML执行多对一映射。
1）一对一映射的持久类有两个持久性类Employee.java和Address.java。雇员类包含地址类引用, 反之亦然。
Employee.java

package com.srcmini; public class Employee { private int employeeId; private String name, email; private Address address; //setters and getters }

Address.java

package com.srcmini; public class Address { private int addressId; private String addressLine1, city, state, country; private int pincode; private Employee employee; //setters and getters }

2）持久类的映射文件这两个映射文件是employee.hbm.xml和address.hbm.xml。
employee.hbm.xml

< ?xml version='1.0' encoding='UTF-8'?> < !DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 5.3//EN" "http://hibernate.sourceforge.net/hibernate-mapping-5.3.dtd"> < hibernate-mapping> < class name="com.srcmini.Employee" table="emp22"> < id name="employeeId"> < generator class="increment"> < /generator> < /id> < property name="name"> < /property> < property name="email"> < /property> < many-to-one name="address" cascade="all"> < /many-to-one> < /class> < /hibernate-mapping>

address.hbm.xml

< ?xml version='1.0' encoding='UTF-8'?> < !DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 5.3//EN" "http://hibernate.sourceforge.net/hibernate-mapping-5.3.dtd"> < hibernate-mapping> < class name="com.srcmini.Address" table="address22"> < id name="addressId"> < generator class="increment"> < /generator> < /id> < property name="addressLine1"> < /property> < property name="city"> < /property> < property name="state"> < /property> < property name="country"> < /property> < property name="pincode"> < /property> < /class> < /hibernate-mapping>

3）配置文件 【使用XML Hibernate多对一映射】该文件包含有关数据库和映射文件的信息。

< ?xml version='1.0' encoding='UTF-8'?> < !DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 5.3//EN" "http://hibernate.sourceforge.net/hibernate-configuration-5.3.dtd"> < hibernate-configuration> < session-factory> < property name="hbm2ddl.auto"> update< /property> < property name="dialect"> org.hibernate.dialect.Oracle9Dialect< /property> < property name="connection.url"> jdbc:oracle:thin:@localhost:1521:xe< /property> < property name="connection.username"> system< /property> < property name="connection.password"> jtp< /property> < property name="connection.driver_class"> oracle.jdbc.driver.OracleDriver< /property> < mapping resource="employee.hbm.xml"/> < mapping resource="address.hbm.xml"/> < /session-factory> < /hibernate-configuration>

4）用于存储和获取数据的用户类 Store.java

package com.srcmini; import org.hibernate.*; import org.hibernate.boot.Metadata; import org.hibernate.boot.MetadataSources; import org.hibernate.boot.registry.StandardServiceRegistry; import org.hibernate.boot.registry.StandardServiceRegistryBuilder; public class Store { public static void main(String[] args) { StandardServiceRegistry ssr=new StandardServiceRegistryBuilder().configure("hibernate.cfg.xml").build(); Metadata meta=new MetadataSources(ssr).getMetadataBuilder().build(); SessionFactory factory=meta.getSessionFactoryBuilder().build(); Session session=factory.openSession(); Transaction t=session.beginTransaction(); Employee e1=new Employee(); e1.setName("Ravi Malik"); e1.setEmail("ravi@gmail.com"); Employee e2=new Employee(); e2.setName("Anuj Verma"); e2.setEmail("anuj@gmail.com"); Address address1=new Address(); address1.setAddressLine1("G-13, Sector 3"); address1.setCity("Noida"); address1.setState("UP"); address1.setCountry("India"); address1.setPincode(201301); e1.setAddress(address1); e2.setAddress(address1); session.persist(e1); session.persist(e2); t.commit(); session.close(); System.out.println("success"); } }

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Fetch.java

package com.srcmini; import java.util.Iterator; import java.util.List; import javax.persistence.TypedQuery; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.boot.Metadata; import org.hibernate.boot.MetadataSources; import org.hibernate.boot.registry.StandardServiceRegistry; import org.hibernate.boot.registry.StandardServiceRegistryBuilder; public class Fetch { public static void main(String[] args) { StandardServiceRegistry ssr=new StandardServiceRegistryBuilder().configure("hibernate.cfg.xml").build(); Metadata meta=new MetadataSources(ssr).getMetadataBuilder().build(); SessionFactory factory=meta.getSessionFactoryBuilder().build(); Session session=factory.openSession(); TypedQuery query=session.createQuery("from Employee e"); List< Employee> list=query.getResultList(); Iterator< Employee> itr=list.iterator(); while(itr.hasNext()){ Employee emp=itr.next(); System.out.println(emp.getEmployeeId()+" "+emp.getName()+" "+emp.getEmail()); Address address=emp.getAddress(); System.out.println(address.getAddressLine1()+" "+address.getCity()+" "+ address.getState()+" "+address.getCountry()+" "+address.getPincode()); }session.close(); System.out.println("success"); } }

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