Hibernate映射关系

1. Hibernate映射关系

新建项目Hibernate08

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>
        <!--数据库连接设置 -->
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="connection.url">jdbc:mysql://localhost:3306/hibernate4</property>
        <property name="connection.username">root</property>
        <property name="connection.password">root</property>
        <!-- 方言 -->
        <property name="dialect">org.hibernate.dialect.MySQL5Dialect</property>
        <!-- 控制台显示SQL -->
        <property name="show_sql">true</property>
        <!-- 自动更新表结构 -->
        <property name="hbm2ddl.auto">update</property>
        <!-- Mapper -->
        <mapping resource="com/andrew/model/User.hbm.xml"/>
        <mapping resource="com/andrew/model/Address.hbm.xml"/>
        <mapping resource="com/andrew/model/User2.hbm.xml"/>
        <mapping resource="com/andrew/model/Address2.hbm.xml"/>
    </session-factory>
</hibernate-configuration>

HibernateUtil.java

package com.andrew.util;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
public class HibernateUtil {
    private static final SessionFactory sessionFactory = buildSessionFactory();
    private static SessionFactory buildSessionFactory() {
        // 1. 实例化配置文件
        Configuration configuration = new Configuration().configure();
        // 2. 实例化服务登记
        ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder()
                .applySettings(configuration.getProperties()).build();
        // 3. 获取Session工厂
        return configuration.buildSessionFactory(serviceRegistry);
    }
    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }
}

1) Hibernate一对一映射关系实现

1.1) 按照主键映射

User.java

package com.andrew.model;
public class User {
    private int id;
    private String name;
    private Address address;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Address getAddress() {
        return address;
    }
    public void setAddress(Address address) {
        this.address = address;
    }
}

User.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.andrew.model">
    <class name="User" table="t_user">
        <id name="id" column="userId">
            <generator class="native"></generator>
        </id>
        <property name="name" column="userName"></property>
        <one-to-one name="address" class="com.andrew.model.Address" cascade="all"></one-to-one>
    </class>
</hibernate-mapping>

Address.java

package com.andrew.model;
public class Address {
    private int id;
    private String address;
    private String zipcode;
    private User user;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    public String getZipcode() {
        return zipcode;
    }
    public void setZipcode(String zipcode) {
        this.zipcode = zipcode;
    }
    public User getUser() {
        return user;
    }
    public void setUser(User user) {
        this.user = user;
    }
}

Address.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.andrew.model">
    <class name="Address" table="t_address">
        <id name="id" column="addressId">
            <generator class="foreign">
                <param name="property">user</param>
            </generator>
        </id>
        <property name="address" column="address"></property>
        <property name="zipcode" column="zipcode"></property>
        <one-to-one name="user" class="com.andrew.model.User" constrained="true"></one-to-one>
    </class>
</hibernate-mapping>

UserTest.java

package com.andrew.service;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import com.andrew.model.Address;
import com.andrew.model.Address2;
import com.andrew.model.User;
import com.andrew.model.User2;
import com.andrew.util.HibernateUtil;
public class UserTest {
    private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
    private Session session;
    @Before
    public void setUp() throws Exception {
        session=sessionFactory.openSession(); // 1. 生成一个session
        session.beginTransaction(); // 2. 开启事务
    }
    @After
    public void tearDown() throws Exception {
         session.getTransaction().commit(); // 3. 提交事务
         session.close(); // 4. 关闭session
    }
    @Test
    public void testSave1() {
        User user = new User();
        user.setName("张三");
        Address address = new Address();
        address.setAddress("某地方");
        address.setZipcode("43242");
        address.setUser(user);
        user.setAddress(address);
        session.save(user);
    }
}

运行结果：
Hibernate: insert into t_user (userName) values (?)
Hibernate: insert into t_address (address, zipcode, addressId) values (?, ?, ?)
数据库
t_address
addressId    address    zipcode
1            某个地方   43242
t_user
userId    userName
1         张三

1.2) 按照外键映射

User2.java

package com.andrew.model;
public class User2 {
    private int id;
    private String name;
    private Address2 address;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Address2 getAddress() {
        return address;
    }
    public void setAddress(Address2 address) {
        this.address = address;
    }
}

User2.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.andrew.model">
    <class name="User2" table="t_user2">
        <id name="id" column="userId">
            <generator class="native"></generator>
        </id>
        <property name="name" column="userName"></property>
        <many-to-one name="address" class="com.andrew.model.Address2" column="addressId" cascade="all" unique="true"></many-to-one>
    </class>
</hibernate-mapping>

Address2.java

package com.andrew.model;
public class Address2 {
    private int id;
    private String address;
    private String zipcode;
    private User2 user;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getAddress() {
        return address;
    }
    public void setAddress(String address) {
        this.address = address;
    }
    public String getZipcode() {
        return zipcode;
    }
    public void setZipcode(String zipcode) {
        this.zipcode = zipcode;
    }
    public User2 getUser() {
        return user;
    }
    public void setUser(User2 user) {
        this.user = user;
    }
}

Address2.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.andrew.model">
    <class name="Address2" table="t_address2">
        <id name="id" column="addressId">
            <generator class="native">
            </generator>
        </id>
        <property name="address" column="address"></property>
        <property name="zipcode" column="zipcode"></property>
        <one-to-one name="user" class="com.andrew.model.User2" property-ref="address"></one-to-one>
    </class>
</hibernate-mapping>

UserTest.java

package com.andrew.service;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import com.andrew.model.Address;
import com.andrew.model.Address2;
import com.andrew.model.User;
import com.andrew.model.User2;
import com.andrew.util.HibernateUtil;
public class UserTest {
    private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
    private Session session;
    @Before
    public void setUp() throws Exception {
        session=sessionFactory.openSession(); // 1. 生成一个session
        session.beginTransaction(); // 2. 开启事务
    }
    @After
    public void tearDown() throws Exception {
         session.getTransaction().commit(); // 3. 提交事务
         session.close(); // 4. 关闭session
    }
    @Test
    public void testSave2() {
        User2 user = new User2();
        user.setName("李四");
        Address2 address = new Address2();
        address.setAddress("某地方2");
        address.setZipcode("432422");
        address.setUser(user);
        user.setAddress(address);
        session.save(user);
    }
}

运行结果：
Hibernate: insert into t_address2 (address, zipcode) values (?, ?)
Hibernate: insert into t_user2 (userName, addressId) values (?, ?)
数据库：
t_address2
addressId    address    zipcode
1            某个地方   43242
t_user2
userId    userName    addressId
1         李四        1

2) Hibernate多对多映射关系实现

新建项目Hibernate08

2.1) 多对多单向实现

Student.java

package com.andrew.model;
import java.util.HashSet;
import java.util.Set;
public class Student {
    private int id;
    private String name;
    private Set<Course> courses = new HashSet<Course>();
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Set<Course> getCourses() {
        return courses;
    }
    public void setCourses(Set<Course> courses) {
        this.courses = courses;
    }
}

Student.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.andrew.model">
    <class name="Student" table="t_student">
        <id name="id" column="studentId">
            <generator class="native"></generator>
        </id>
        <property name="name" column="studentName"></property>
        <set name="courses" table="student_course" cascade="save-update">
            <key column="student_id"></key>
            <many-to-many class="com.andrew.model.Course" column="course_id"></many-to-many>
        </set>
    </class>
</hibernate-mapping>

Course.java

package com.andrew.model;
public class Course {
    private int id;
    private String name;
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
}

Course.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.andrew.model">
    <class name="Course" table="t_course">
        <id name="id" column="courseId">
            <generator class="native"></generator>
        </id>
        <property name="name" column="courseName"></property>
    </class>
</hibernate-mapping>

StudentTest.java

package com.andrew.service;
import java.util.Iterator;
import java.util.Set;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import com.andrew.model.Course;
import com.andrew.model.Course2;
import com.andrew.model.Student;
import com.andrew.model.Student2;
import com.andrew.util.HibernateUtil;
public class StudentTest {
    private SessionFactory sessionFactory = HibernateUtil.getSessionFactory();
    private Session session;
    @Before
    public void setUp() throws Exception {
        session = sessionFactory.openSession(); // 1. 生成一个session
        session.beginTransaction(); // 2. 开启事务
    }
    @After
    public void tearDown() throws Exception {
        session.getTransaction().commit(); // 3. 提交事务
        session.close(); // 4. 关闭session
    }
    @Test
    public void testSave1() {
        Course course1 = new Course();
        course1.setName("语文");
        Course course2 = new Course();
        course2.setName("数学");
        Student student1 = new Student();
        student1.setName("张三");
        student1.getCourses().add(course1);
        student1.getCourses().add(course2);
        Student student2 = new Student();
        student2.setName("李四");
        student2.getCourses().add(course1);
        student2.getCourses().add(course2);
        session.save(student1);
        session.save(student2);
    }
    @Test
    public void testLoad1() {
        Student student = (Student) session.get(Student.class, 1);
        Set<Course> courses = (Set<Course>) student.getCourses();
        Iterator it = courses.iterator();
        while (it.hasNext()) {
            Course c = (Course) it.next();
            System.out.println(c.getName());
        }
    }
}

运行结果：
Hibernate: insert into t_student (studentName) values (?)
Hibernate: insert into t_course (courseName) values (?)
Hibernate: insert into t_course (courseName) values (?)
Hibernate: insert into t_student (studentName) values (?)
Hibernate: insert into student_course (student_id, course_id) values (?, ?)
Hibernate: insert into student_course (student_id, course_id) values (?, ?)
Hibernate: insert into student_course (student_id, course_id) values (?, ?)
Hibernate: insert into student_course (student_id, course_id) values (?, ?)
数据库：
t_student
studentId    studentName
1            张三
2            李四
t_course
courseId    courseName
1           语文
2           数学
student_course
student_id    course_id
1             1
1             2
2             1
2             2
运行结果：
Hibernate: select student0_.studentId as studentI1_4_0_, student0_.studentName as studentN2_4_0_ from t_student student0_ where student0_.studentId=?
Hibernate: select courses0_.student_id as student_1_4_0_, courses0_.course_id as course_i2_0_0_, course1_.courseId as courseId1_2_1_, course1_.courseName as courseNa2_2_1_ from student_course courses0_ inner join t_course course1_ on courses0_.course_id=course1_.courseId where courses0_.student_id=?
数学
语文

2.2) 多对多双向实现

Student2.java

package com.andrew.model;
import java.util.HashSet;
import java.util.Set;
public class Student2 {
    private int id;
    private String name;
    private Set<Course2> courses = new HashSet<Course2>();
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Set<Course2> getCourses() {
        return courses;
    }
    public void setCourses(Set<Course2> courses) {
        this.courses = courses;
    }
}

Student2.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.andrew.model">
    <class name="Student2" table="t_student2">
        <id name="id" column="studentId">
            <generator class="native"></generator>
        </id>
        <property name="name" column="studentName"></property>
        <set name="courses" table="student_course2" cascade="save-update">
            <key column="student_id"></key>
            <many-to-many class="com.andrew.model.Course2" column="course_id"></many-to-many>
        </set>
    </class>
</hibernate-mapping>

Course2.java

package com.andrew.model;
import java.util.HashSet;
import java.util.Set;
public class Course2 {
    private int id;
    private String name;
    private Set<Student2> students = new HashSet<Student2>();
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public Set<Student2> getStudents() {
        return students;
    }
    public void setStudents(Set<Student2> students) {
        this.students = students;
    }
}

Course2.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.andrew.model">
    <class name="Course2" table="t_course2">
        <id name="id" column="courseId">
            <generator class="native"></generator>
        </id>
        <property name="name" column="courseName"></property>
        <set name="students" table="student_course2" inverse="true" >
            <key column="course_id"></key>
            <many-to-many class="com.andrew.model.Student2" column="student_id"></many-to-many>
        </set>
    </class>
</hibernate-mapping>

StudentTest.java

package com.andrew.service;
import java.util.Iterator;
import java.util.Set;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import com.andrew.model.Course;
import com.andrew.model.Course2;
import com.andrew.model.Student;
import com.andrew.model.Student2;
import com.andrew.util.HibernateUtil;
public class StudentTest {
    private SessionFactory sessionFactory = HibernateUtil.getSessionFactory();
    private Session session;
    @Before
    public void setUp() throws Exception {
        session = sessionFactory.openSession(); // 1. 生成一个session
        session.beginTransaction(); // 2. 开启事务
    }
    @After
    public void tearDown() throws Exception {
        session.getTransaction().commit(); // 3. 提交事务
        session.close(); // 4. 关闭session
    }
    @Test
    public void testSave2() {
        Course2 course1 = new Course2();
        course1.setName("语文");
        Course2 course2 = new Course2();
        course2.setName("数学");
        Student2 student1 = new Student2();
        student1.setName("张三");
        student1.getCourses().add(course1);
        student1.getCourses().add(course2);
        Student2 student2 = new Student2();
        student2.setName("李四");
        student2.getCourses().add(course1);
        student2.getCourses().add(course2);
        session.save(student1);
        session.save(student2);
    }
    @Test
    public void testLoad2() {
        Course2 course = (Course2) session.get(Course2.class, 1);
        Set<Student2> students = (Set<Student2>) course.getStudents();
        Iterator it = students.iterator();
        while (it.hasNext()) {
            Student2 s = (Student2) it.next();
            System.out.println(s.getName());
        }

    }
}

运行结果：
Hibernate: insert into t_student2 (studentName) values (?)
Hibernate: insert into t_course2 (courseName) values (?)
Hibernate: insert into t_course2 (courseName) values (?)
Hibernate: insert into t_student2 (studentName) values (?)
Hibernate: insert into student_course2 (student_id, course_id) values (?, ?)
Hibernate: insert into student_course2 (student_id, course_id) values (?, ?)
Hibernate: insert into student_course2 (student_id, course_id) values (?, ?)
Hibernate: insert into student_course2 (student_id, course_id) values (?, ?)
数据库：
t_student
studentId    studentName
1            张三
2            李四
t_course2
courseId    courseName
1           语文
2           数学
student_course2
student_id    course_id
1             1
1             2
2             1
2             2
运行结果：
Hibernate: select course2x0_.courseId as courseId1_3_0_, course2x0_.courseName as courseNa2_3_0_ from t_course2 course2x0_ where course2x0_.courseId=?
Hibernate: select students0_.course_id as course_i2_3_0_, students0_.student_id as student_1_1_0_, student2x1_.studentId as studentI1_5_1_, student2x1_.studentName as studentN2_5_1_ from student_course2 students0_ inner join t_student2 student2x1_ on students0_.student_id=student2x1_.studentId where students0_.course_id=?
张三
李四