博文

package cc.www.hibernateproject.model;


public class Student {
  private int id;
  private String name;
  private Teacher teacher;


  public Teacher getTeacher() {
    return teacher;
  }

  public void setTeacher(Teacher teacher) {
    this.teacher = teacher;
  }

  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 Student() {
    // TODO Auto-generated constructor stub
  }

  public Student(String name) {
    this.name = name;
  }

  @Override
  public String toString() {
    return "Student [id=" + id + ", name=" + name + ", teacher=" + teacher + "]";
  }

}

Teacher.java

package cc.www.hibernateproject.model;

import java.util.HashSet;
import java.util.Set;


public class Teacher {
  private int id;

  private String name;

  private Set<Student> student=new HashSet<Student>();
  

  public Set<Student> getStudent() {
    return student;
  }

  public void setStudent(Set<Student> student) {
    this.student = student;
  }

  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 Teacher() {
    // TODO Auto-generated constructor stub
  }

  public Teacher(String name) {
    this.name = name;
  }

  @Override
  public String toString() {
    return "Teacher [id=" + id + ", name=" + name + "]";
  }

}

Student.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2020-1-2 12:38:04 by Hibernate Tools 3.5.0.Final -->
<hibernate-mapping>
    <class name="cc.www.hibernateproject.model.Student" table="t_student">
        <id name="id" type="int">
            <column name="id" />
            <generator class="native" />
        </id>
        <property name="name" type="java.lang.String">
            <column name="name" />
        </property>
        <many-to-one name="teacher" class="cc.www.hibernateproject.model.Teacher">
            <column name="student_id" />
        </many-to-one>
    </class>
</hibernate-mapping>

Teacher.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2020-1-2 12:38:04 by Hibernate Tools 3.5.0.Final -->
<hibernate-mapping>
    <class name="cc.www.hibernateproject.model.Teacher" table="t_teacher">
        <id name="id" type="int">
            <column name="id" />
            <generator class="native" />
        </id>
        <property name="name" type="java.lang.String">
            <column name="name" />
        </property>
        <set name="student" table="t_student" inverse="false" lazy="true" fetch="join">
            <key>
                <column name="student_id" />
            </key>
            <one-to-many class="cc.www.hibernateproject.model.Student" />
        </set>
    </class>
</hibernate-mapping>

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>
  <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
  <property name="hibernate.connection.url">jdbc:mysql://127.0.0.1:3306/hibernateproject?characterEncoding=utf8&amp;amp;useSSL=false</property>
  <property name="hibernate.connection.username">root</property>
  <property name="hibernate.connection.password">123456</property>
  <property name="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>
  <property name="hibernate.show_sql">true</property>
  <property name="hibernate.format_sql">true</property>
  <!-- 选择使用C3P0连接池 -->
  <property name="hibernate.connection.provider_class">org.hibernate.c3p0.internal.C3P0ConnectionProvider</property>
  <!-- 最大连接数 -->
  <property name="hibernate.c3p0.max_size">20</property>
  <!-- 最小连接数 -->
  <property name="hibernate.c3p0.min_size">5</property>
  <!-- 获得连接的超时时间,如果超过这个时间,会抛出异常，单位毫秒 -->
  <property name="hibernate.c3p0.timeout">120</property>
  <!-- 最大的PreparedStatement的数量 -->
  <property name="hibernate.c3p0.max_statements">100</property>
  <!-- 每隔120秒检查连接池里的空闲连接 ，单位是秒 -->
  <property name="hibernate.c3p0.idle_test_period">120</property>
  <!-- 当连接池里面的连接用完的时候，C3P0一下获取的新的连接数 -->
  <property name="hibernate.c3p0.acquire_increment">2</property>
  <property name="hibernate.hbm2ddl.auto">update</property>


  <mapping resource="cc/www/hibernateproject/model/Teacher.hbm.xml"/>
  <mapping resource="cc/www/hibernateproject/model/Student.hbm.xml"/>


 </session-factory>
</hibernate-configuration>

StudentEntityTest.java

package cc.www.hibernatedemo.model;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.query.Query;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

import com.mysql.fabric.xmlrpc.base.Array;

import cc.www.hibernateproject.model.Student;
import cc.www.hibernateproject.model.Teacher;

import java.util.Arrays;
import java.util.Date;
import java.util.HashSet;
import java.util.List;
import java.util.Set;

import javax.xml.transform.Source;

@SuppressWarnings("unused")
public class StudentEntityTest {
    private SessionFactory sessionFactory=null;
    private Session session =null;
    private Transaction transaction =null;
    
    @Before
    public void init(){
      //测试同步21
        //System.out.println("开始测试文件");
        //返回的configureation,包含有配置文件里的具体信息
      
        Configuration configure = new Configuration().configure();
        //创建一个SessionFactory工厂类,通过它建立一个数据库连接会话,Session
        sessionFactory= configure.buildSessionFactory();
        
        //通过工厂类开启Session对
        session = sessionFactory.openSession();
        
        //开始事务
        transaction = session.beginTransaction();
    }
    
    
    @After
    public void destroy(){
        //System.out.println("结束");
        //提交事务
        transaction.commit();
        
        //关闭
        session.close();
        
        //关闭工厂
        sessionFactory.close();
    }
    
    
    @Test
    public void test() {
      
//      Student student1 = new Student("张三");
//      Student student2 = new Student("张四");
//      Student student3 = new Student("张五");
//      Student student4 = new Student("张六");
//      
//      
//      HashSet<Student> students = new HashSet<Student>();
//      students.add(student1);
//      students.add(student2);
//      
//         
//      HashSet<Student> students2 = new HashSet<Student>();
//      students.add(student3);
//      students.add(student4);
//      
//      
//      Teacher teacher = new Teacher("黄老师");
//      teacher.setStudent(students);
//      Teacher teacher1 = new Teacher("张老师");
//      teacher.setStudent(students2);
//
//      student1.setTeacher(teacher);
//      student2.setTeacher(teacher);
//      student3.setTeacher(teacher1);
//      student4.setTeacher(teacher1);
//
//      session.save(student1);
//      session.save(student2);
//      session.save(student3);
//      session.save(student4);
//      
//      session.save(teacher);
//      session.save(teacher1);
      

      
      //form Teacher是类
//      String hqlString ="from Teacher";
//      @SuppressWarnings("unchecked")
//    Query<Teacher> query =session.createQuery(hqlString);
//      List<Teacher> teachers = query.list();
//      System.out.println(teachers);
//   
//      
//      //遍历Tercher
//      for(Teacher t:teachers) {
//        System.out.println(t.getStudent().size());
//      }
      
      Teacher teacher =session.load(Teacher.class, 1);
      System.out.println(teacher.getStudent().size());
          
      
    }
}

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