（十）Hibernate 查询方式

 所有项目导入对应的hibernate的jar包、mysql的jar包和添加每次都需要用到的HibernateUtil.java

第一节：Hibernate 查询方式简介

1，导航对象图查询方式；

2，OID 查询方式；

3，本地SQL 查询方式；

4，HQL 查询方式；

5，QBC 查询方式；(Query By Criteria)

第二节：本地SQL 查询方式

Student.java

 package com.wishwzp.model;

 public class Student {

     private int id;
     private String name;
     private int age;

     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 int getAge() {
         return age;
     }
     public void setAge(int age) {
         this.age = age;
     }
     @Override
     public String toString() {
         return "Student [id=" + id + ", name=" + name + ", age=" + age + "]";
     }

 }

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.wishwzp.model">

     <class name="Student" table="t_student">
         <id name="id" column="stuId">
             <generator class="native"></generator>
         </id>

         <property name="name" column="stuName"></property>
         <property name="age" column="stuAge"></property>
     </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>

         <!--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/hibernate</property>
         <property name="connection.username">root</property>
         <property name="connection.password">123456</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>

           <mapping resource="com/wishwzp/model/Student.hbm.xml"/>

     </session-factory>

 </hibernate-configuration>

StudentTest.java

 package com.wishwzp.service;

 import java.util.Iterator;
 import java.util.List;

 import org.hibernate.Query;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;

 import com.wishwzp.model.Student;
 import com.wishwzp.util.HibernateUtil;

 public class StudentTest {

     private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
     private Session session;

     @Before
     public void setUp() throws Exception {
         session=sessionFactory.openSession(); // 生成一个session
         session.beginTransaction(); // 开启事务
     }

     @After
     public void tearDown() throws Exception {
          session.getTransaction().commit(); // 提交事务
          session.close(); // 关闭session
     }

     @Test
     public void testSQLQuery() {

     }

 }

运行结果生成了数据库信息：

我们插入一些数据：

再次写代码查询里面的数据：

StudentTest.java

 package com.wishwzp.service;

 import java.util.Iterator;
 import java.util.List;

 import org.hibernate.Query;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;

 import com.wishwzp.model.Student;
 import com.wishwzp.util.HibernateUtil;

 public class StudentTest {

     private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
     private Session session;

     @Before
     public void setUp() throws Exception {
         session=sessionFactory.openSession(); // 生成一个session
         session.beginTransaction(); // 开启事务
     }

     @After
     public void tearDown() throws Exception {
          session.getTransaction().commit(); // 提交事务
          session.close(); // 关闭session
     }

     @Test
     public void testSQLQuery() {
         String sql="select * from t_student";
         Query query=session.createSQLQuery(sql).addEntity(Student.class);
         List studentList=query.list();
         Iterator it=studentList.iterator();
         while(it.hasNext()){
             Student s=(Student)it.next();
             System.out.println(s);
         }
     }

 }

运行结果显示：

我们写一个带参数的查询语句查询：

StudentTest.java

 package com.wishwzp.service;

 import java.util.Iterator;
 import java.util.List;

 import org.hibernate.Query;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;

 import com.wishwzp.model.Student;
 import com.wishwzp.util.HibernateUtil;

 public class StudentTest {

     private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
     private Session session;

     @Before
     public void setUp() throws Exception {
         session=sessionFactory.openSession(); // 生成一个session
         session.beginTransaction(); // 开启事务
     }

     @After
     public void tearDown() throws Exception {
          session.getTransaction().commit(); // 提交事务
          session.close(); // 关闭session
     }

     @Test
     public void testSQLQuery2() {
         String sql="select * from t_student where stuName like :stuName and stuAge=:stuAge";
         Query query=session.createSQLQuery(sql).addEntity(Student.class);
         query.setString("stuName", "张%");
         query.setInteger("stuAge", 10);
         List studentList=query.list();
         Iterator it=studentList.iterator();
         while(it.hasNext()){
             Student s=(Student)it.next();
             System.out.println(s);
         }
     }

 }

运行结果显示：

第三节：HQL 查询方式

HQL（Hibernate Query Language）是面向对象的查询语言；是使用最广的一种查询方式；

1，普通查询；

2，带条件查询；

3，使用别名；

4，对结果排序；

5，分页查询；

6，查询单个对象；

7，链式写法；

1，普通查询；

StudentTest.java

 package com.wishwzp.service;

 import java.util.Iterator;
 import java.util.List;

 import org.hibernate.Query;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;

 import com.wishwzp.model.Student;
 import com.wishwzp.util.HibernateUtil;

 public class StudentTest {

     private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
     private Session session;

     @Before
     public void setUp() throws Exception {
         session=sessionFactory.openSession(); // 生成一个session
         session.beginTransaction(); // 开启事务
     }

     @After
     public void tearDown() throws Exception {
          session.getTransaction().commit(); // 提交事务
          session.close(); // 关闭session
     }

     @Test
     public void testHQLQuery() {
         String hql="from Student";
         Query query=session.createQuery(hql);
         List<Student> studentList=(List<Student>)query.list();
         Iterator it=studentList.iterator();
         while(it.hasNext()){
             Student s=(Student)it.next();
             System.out.println(s);
         }
     }

 }

运行结果显示：

2，带条件查询；

StudentTest.java

 package com.wishwzp.service;

 import java.util.Iterator;
 import java.util.List;

 import org.hibernate.Query;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;

 import com.wishwzp.model.Student;
 import com.wishwzp.util.HibernateUtil;

 public class StudentTest {

     private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
     private Session session;

     @Before
     public void setUp() throws Exception {
         session=sessionFactory.openSession(); // 生成一个session
         session.beginTransaction(); // 开启事务
     }

     @After
     public void tearDown() throws Exception {
          session.getTransaction().commit(); // 提交事务
          session.close(); // 关闭session
     }

     @Test
     public void testHQLQuery2() {
         String hql="from Student where name like :stuName and age=:stuAge";
         Query query=session.createQuery(hql);
         query.setString("stuName", "张%");
         query.setInteger("stuAge", 10);
         List<Student> studentList=(List<Student>)query.list();
         Iterator it=studentList.iterator();
         while(it.hasNext()){
             Student s=(Student)it.next();
             System.out.println(s);
         }
     }

 }

运行结果显示：

Hibernate: select student0_.stuId as stuId1_0_, student0_.stuName as stuName2_0_, student0_.stuAge as stuAge3_0_ from t_student student0_ where (student0_.stuName like ?) and student0_.stuAge=?
Student [id=1, name=张三, age=10]

3，使用别名；

StudentTest.java

 package com.wishwzp.service;

 import java.util.Iterator;
 import java.util.List;

 import org.hibernate.Query;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;

 import com.wishwzp.model.Student;
 import com.wishwzp.util.HibernateUtil;

 public class StudentTest {

     private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
     private Session session;

     @Before
     public void setUp() throws Exception {
         session=sessionFactory.openSession(); // 生成一个session
         session.beginTransaction(); // 开启事务
     }

     @After
     public void tearDown() throws Exception {
          session.getTransaction().commit(); // 提交事务
          session.close(); // 关闭session
     }

     @Test
     public void testHQLQuery3() {
         String hql="from Student as s where s.name like :stuName and s.age=:stuAge";
         Query query=session.createQuery(hql);
         query.setString("stuName", "张%");
         query.setInteger("stuAge", 10);
         List<Student> studentList=(List<Student>)query.list();
         Iterator it=studentList.iterator();
         while(it.hasNext()){
             Student s=(Student)it.next();
             System.out.println(s);
         }
     }

 }

运行结果显示：

Hibernate: select student0_.stuId as stuId1_0_, student0_.stuName as stuName2_0_, student0_.stuAge as stuAge3_0_ from t_student student0_ where (student0_.stuName like ?) and student0_.stuAge=?
Student [id=1, name=张三, age=10]

4，对结果排序；

StudentTest.java

 package com.wishwzp.service;

 import java.util.Iterator;
 import java.util.List;

 import org.hibernate.Query;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;

 import com.wishwzp.model.Student;
 import com.wishwzp.util.HibernateUtil;

 public class StudentTest {

     private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
     private Session session;

     @Before
     public void setUp() throws Exception {
         session=sessionFactory.openSession(); // 生成一个session
         session.beginTransaction(); // 开启事务
     }

     @After
     public void tearDown() throws Exception {
          session.getTransaction().commit(); // 提交事务
          session.close(); // 关闭session
     }

     @Test
     public void testHQLQuery4() {
         String hql="from Student order by age desc";
         Query query=session.createQuery(hql);
         List<Student> studentList=(List<Student>)query.list();
         Iterator it=studentList.iterator();
         while(it.hasNext()){
             Student s=(Student)it.next();
             System.out.println(s);
         }
     }

 }

运行结果显示：

Hibernate: select student0_.stuId as stuId1_0_, student0_.stuName as stuName2_0_, student0_.stuAge as stuAge3_0_ from t_student student0_ order by student0_.stuAge desc
Student [id=2, name=李四, age=15]
Student [id=3, name=王五, age=13]
Student [id=1, name=张三, age=10]

5，分页查询；

StudentTest.java

 package com.wishwzp.service;

 import java.util.Iterator;
 import java.util.List;

 import org.hibernate.Query;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;

 import com.wishwzp.model.Student;
 import com.wishwzp.util.HibernateUtil;

 public class StudentTest {

     private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
     private Session session;

     @Before
     public void setUp() throws Exception {
         session=sessionFactory.openSession(); // 生成一个session
         session.beginTransaction(); // 开启事务
     }

     @After
     public void tearDown() throws Exception {
          session.getTransaction().commit(); // 提交事务
          session.close(); // 关闭session
     }

     @Test
     public void testHQLQuery5() {
         String hql="from Student";
         Query query=session.createQuery(hql);
         query.setFirstResult(1);
         query.setMaxResults(2);
         List<Student> studentList=(List<Student>)query.list();
         Iterator it=studentList.iterator();
         while(it.hasNext()){
             Student s=(Student)it.next();
             System.out.println(s);
         }
     }

 }

运行结果显示：

Hibernate: select student0_.stuId as stuId1_0_, student0_.stuName as stuName2_0_, student0_.stuAge as stuAge3_0_ from t_student student0_ limit ?, ?
Student [id=2, name=李四, age=15]
Student [id=3, name=王五, age=13]

6，查询单个对象；

StudentTest.java

 package com.wishwzp.service;

 import java.util.Iterator;
 import java.util.List;

 import org.hibernate.Query;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;

 import com.wishwzp.model.Student;
 import com.wishwzp.util.HibernateUtil;

 public class StudentTest {

     private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
     private Session session;

     @Before
     public void setUp() throws Exception {
         session=sessionFactory.openSession(); // 生成一个session
         session.beginTransaction(); // 开启事务
     }

     @After
     public void tearDown() throws Exception {
          session.getTransaction().commit(); // 提交事务
          session.close(); // 关闭session
     }

     @Test
     public void testHQLQuery6() {
         String hql="from Student";
         Query query=session.createQuery(hql);
         query.setFirstResult(1);
         query.setMaxResults(1);
         Student student=(Student)query.uniqueResult();
         System.out.println(student);
     }

 }

运行结果显示：

Hibernate: select student0_.stuId as stuId1_0_, student0_.stuName as stuName2_0_, student0_.stuAge as stuAge3_0_ from t_student student0_ limit ?, ?
Student [id=2, name=李四, age=15]

7，链式写法；

StudentTest.java

 package com.wishwzp.service;

 import java.util.Iterator;
 import java.util.List;

 import org.hibernate.Query;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;

 import com.wishwzp.model.Student;
 import com.wishwzp.util.HibernateUtil;

 public class StudentTest {

     private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
     private Session session;

     @Before
     public void setUp() throws Exception {
         session=sessionFactory.openSession(); // 生成一个session
         session.beginTransaction(); // 开启事务
     }

     @After
     public void tearDown() throws Exception {
          session.getTransaction().commit(); // 提交事务
          session.close(); // 关闭session
     }

     @Test
     public void testHQLQuery7() {
         String hql="from Student as s where s.name like :stuName and s.age=:stuAge";
         Query query=session.createQuery(hql);
         List<Student> studentList=(List<Student>)query
                 .setString("stuName", "张%")
                 .setInteger("stuAge", 10)
                 .list();
         Iterator it=studentList.iterator();
         while(it.hasNext()){
             Student s=(Student)it.next();
             System.out.println(s);
         }
     }
 }

运行结果显示：

Hibernate: select student0_.stuId as stuId1_0_, student0_.stuName as stuName2_0_, student0_.stuAge as stuAge3_0_ from t_student student0_ where (student0_.stuName like ?) and student0_.stuAge=?
Student [id=1, name=张三, age=10]

第四节：QBC 查询方式

QBC 查询方式(Query By Criteria)是用一套接口来实现的查询方式；

1，普通查询；

2，带条件查询；

3，对结果排序；

4，分页查询；

5，查询单个对象；

6，链式写法；

1，普通查询；

StudentTest.java

 package com.wishwzp.service;

 import java.util.Iterator;
 import java.util.List;

 import org.hibernate.Criteria;
 import org.hibernate.Query;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.hibernate.criterion.Criterion;
 import org.hibernate.criterion.Order;
 import org.hibernate.criterion.Restrictions;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;

 import com.wishwzp.model.Student;
 import com.wishwzp.util.HibernateUtil;

 public class StudentTest {

     private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
     private Session session;

     @Before
     public void setUp() throws Exception {
         session=sessionFactory.openSession(); // 生成一个session
         session.beginTransaction(); // 开启事务
     }

     @After
     public void tearDown() throws Exception {
          session.getTransaction().commit(); // 提交事务
          session.close(); // 关闭session
     }

     @Test
     public void testQBCQuery1(){
         Criteria criteria=session.createCriteria(Student.class);
         List<Student> studentList=criteria.list();
         Iterator it=studentList.iterator();
         while(it.hasNext()){
             Student s=(Student)it.next();
             System.out.println(s);
         }
     }

 }

运行结果显示：

Hibernate: select this_.stuId as stuId1_0_0_, this_.stuName as stuName2_0_0_, this_.stuAge as stuAge3_0_0_ from t_student this_
Student [id=1, name=张三, age=10]
Student [id=2, name=李四, age=15]
Student [id=3, name=王五, age=13]

2，带条件查询；

StudentTest.java

 package com.wishwzp.service;

 import java.util.Iterator;
 import java.util.List;

 import org.hibernate.Criteria;
 import org.hibernate.Query;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.hibernate.criterion.Criterion;
 import org.hibernate.criterion.Order;
 import org.hibernate.criterion.Restrictions;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;

 import com.wishwzp.model.Student;
 import com.wishwzp.util.HibernateUtil;

 public class StudentTest {

     private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
     private Session session;

     @Before
     public void setUp() throws Exception {
         session=sessionFactory.openSession(); // 生成一个session
         session.beginTransaction(); // 开启事务
     }

     @After
     public void tearDown() throws Exception {
          session.getTransaction().commit(); // 提交事务
          session.close(); // 关闭session
     }

     @Test
     public void testQBCQuery2(){
         Criteria criteria=session.createCriteria(Student.class);
         Criterion c1=Restrictions.like("name", "张%");
         Criterion c2=Restrictions.eq("age", 10);
         criteria.add(c1);
         criteria.add(c2);
         List<Student> studentList=criteria.list();
         Iterator it=studentList.iterator();
         while(it.hasNext()){
             Student s=(Student)it.next();
             System.out.println(s);
         }
     }

 }

运行结果显示：

Hibernate: select this_.stuId as stuId1_0_0_, this_.stuName as stuName2_0_0_, this_.stuAge as stuAge3_0_0_ from t_student this_ where this_.stuName like ? and this_.stuAge=?
Student [id=1, name=张三, age=10]

3，对结果排序；

StudentTest.java

 package com.wishwzp.service;

 import java.util.Iterator;
 import java.util.List;

 import org.hibernate.Criteria;
 import org.hibernate.Query;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.hibernate.criterion.Criterion;
 import org.hibernate.criterion.Order;
 import org.hibernate.criterion.Restrictions;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;

 import com.wishwzp.model.Student;
 import com.wishwzp.util.HibernateUtil;

 public class StudentTest {

     private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
     private Session session;

     @Before
     public void setUp() throws Exception {
         session=sessionFactory.openSession(); // 生成一个session
         session.beginTransaction(); // 开启事务
     }

     @After
     public void tearDown() throws Exception {
          session.getTransaction().commit(); // 提交事务
          session.close(); // 关闭session
     }

     @Test
     public void testQBCQuery3(){
         Criteria criteria=session.createCriteria(Student.class);
         criteria.addOrder(Order.desc("age"));
         List<Student> studentList=criteria.list();
         Iterator it=studentList.iterator();
         while(it.hasNext()){
             Student s=(Student)it.next();
             System.out.println(s);
         }
     }

 }

运行结果显示：

Hibernate: select this_.stuId as stuId1_0_0_, this_.stuName as stuName2_0_0_, this_.stuAge as stuAge3_0_0_ from t_student this_ order by this_.stuAge desc
Student [id=2, name=李四, age=15]
Student [id=3, name=王五, age=13]
Student [id=1, name=张三, age=10]

4，分页查询；

StudentTest.java

 package com.wishwzp.service;

 import java.util.Iterator;
 import java.util.List;

 import org.hibernate.Criteria;
 import org.hibernate.Query;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.hibernate.criterion.Criterion;
 import org.hibernate.criterion.Order;
 import org.hibernate.criterion.Restrictions;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;

 import com.wishwzp.model.Student;
 import com.wishwzp.util.HibernateUtil;

 public class StudentTest {

     private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
     private Session session;

     @Before
     public void setUp() throws Exception {
         session=sessionFactory.openSession(); // 生成一个session
         session.beginTransaction(); // 开启事务
     }

     @After
     public void tearDown() throws Exception {
          session.getTransaction().commit(); // 提交事务
          session.close(); // 关闭session
     }

     @Test
     public void testQBCQuery4(){
         Criteria criteria=session.createCriteria(Student.class);
         criteria.setFirstResult(2);
         criteria.setMaxResults(2);
         List<Student> studentList=criteria.list();
         Iterator it=studentList.iterator();
         while(it.hasNext()){
             Student s=(Student)it.next();
             System.out.println(s);
         }
     }

 }

运行结果显示：

Hibernate: select this_.stuId as stuId1_0_0_, this_.stuName as stuName2_0_0_, this_.stuAge as stuAge3_0_0_ from t_student this_ limit ?, ?
Student [id=3, name=王五, age=13]

5，查询单个对象；

StudentTest.java

 package com.wishwzp.service;

 import java.util.Iterator;
 import java.util.List;

 import org.hibernate.Criteria;
 import org.hibernate.Query;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.hibernate.criterion.Criterion;
 import org.hibernate.criterion.Order;
 import org.hibernate.criterion.Restrictions;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;

 import com.wishwzp.model.Student;
 import com.wishwzp.util.HibernateUtil;

 public class StudentTest {

     private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
     private Session session;

     @Before
     public void setUp() throws Exception {
         session=sessionFactory.openSession(); // 生成一个session
         session.beginTransaction(); // 开启事务
     }

     @After
     public void tearDown() throws Exception {
          session.getTransaction().commit(); // 提交事务
          session.close(); // 关闭session
     }

     @Test
     public void testQBCQuery5(){
         Criteria criteria=session.createCriteria(Student.class);
         criteria.setFirstResult(2);
         criteria.setMaxResults(1);
         Student student=(Student)criteria.uniqueResult();
         System.out.println(student);
     }

 }

运行结果显示：

Hibernate: select this_.stuId as stuId1_0_0_, this_.stuName as stuName2_0_0_, this_.stuAge as stuAge3_0_0_ from t_student this_ limit ?, ?
Student [id=3, name=王五, age=13]

6，链式写法；

StudentTest.java

 package com.wishwzp.service;

 import java.util.Iterator;
 import java.util.List;

 import org.hibernate.Criteria;
 import org.hibernate.Query;
 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.hibernate.criterion.Criterion;
 import org.hibernate.criterion.Order;
 import org.hibernate.criterion.Restrictions;
 import org.junit.After;
 import org.junit.Before;
 import org.junit.Test;

 import com.wishwzp.model.Student;
 import com.wishwzp.util.HibernateUtil;

 public class StudentTest {

     private SessionFactory sessionFactory=HibernateUtil.getSessionFactory();
     private Session session;

     @Before
     public void setUp() throws Exception {
         session=sessionFactory.openSession(); // 生成一个session
         session.beginTransaction(); // 开启事务
     }

     @After
     public void tearDown() throws Exception {
          session.getTransaction().commit(); // 提交事务
          session.close(); // 关闭session
     }

     @Test
     public void testQBCQuery6(){
         Criteria criteria=session.createCriteria(Student.class);
         List<Student> studentList=criteria
                 .setFirstResult(0)
                 .setMaxResults(2)
                 .list();
         Iterator it=studentList.iterator();
         while(it.hasNext()){
             Student s=(Student)it.next();
             System.out.println(s);
         }
     }

 }

运行结果显示：

Hibernate: select this_.stuId as stuId1_0_0_, this_.stuName as stuName2_0_0_, this_.stuAge as stuAge3_0_0_ from t_student this_ limit ?
Student [id=1, name=张三, age=10]
Student [id=2, name=李四, age=15]

---

END