Hibernate CRUD操作

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博客地址：http://www.cnblogs.com/caoyc/p/5594789.html 

对于Hibernate的增删改查，我们还是用一个案例来说明

下面是整个项目的目录结构：

一、com.mypro.domain包

1、封装person域模型

 package com.mypro.domain;

 public class Person {

     private int id;
     private String name;
     private int age;
     private String gender;
     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;
     }
     public String getGender() {
         return gender;
     }
     public void setGender(String gender) {
         this.gender = gender;
     }
     @Override
     public String toString() {
         return "Person [id=" + id + ", name=" + name + ", age=" + age
                 + ", gender=" + gender + "]";
     }
     public Person(int id, String name, int age, String gender) {
         super();
         this.id = id;
         this.name = name;
         this.age = age;
         this.gender = gender;
     }
     public Person() {
         super();
     }

 }

Person.java

2、定义QueryResult用来返回分页查询结果集以及表总所有记录数据的封装

 package com.mypro.domain;

 import java.util.List;

 public class QueryResult {

     //返回数据库中某表总的记录数
     private long count;
     //返回结果集
     private List list;
     public long getCount() {
         return count;
     }
     public void setCount(long count) {
         this.count = count;
     }
     public List getList() {
         return list;
     }
     public void setList(List list) {
         this.list = list;
     }
     public QueryResult(long count, List list) {
         super();
         this.count = count;
         this.list = list;
     }
     public QueryResult() {
         super();
     }

 }

QueryResult.java

3、定义Person类和数据库表的映射关系

 <?xml version="1.0"?>

 <!DOCTYPE hibernate-mapping PUBLIC
         "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
         "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
 <hibernate-mapping package="com.mypro.domain">
     <class name="Person" table="person">
         <id name="id" column="Id" type="int">
             <generator class="native"></generator>
         </id>
         <property name="name" column="name" type="string"></property>
         <property name="age" column="Age" type="int"></property>
         <property name="gender" column="Gender" type="string"></property>
     </class>
 </hibernate-mapping>

Person.hbm.xml

二、com.mypro.dao包

1、定一个IPerson的接口，以及接口需要实现的方法

 package com.mypro.dao;

 import java.util.List;

 import com.mypro.domain.Person;
 import com.mypro.domain.QueryResult;

 public interface IPerson {

     /**
      * 添加Person
      * @param person
      */
      void add(Person person);

      /**
       * 通过ID删除Person
       * @param id
       */
      void delete(int id);

      /**
       * 修改Person信息
       * @param person
       */
      void update(Person person);

      /**
       * 通过ID获取Person
       * @param id
       * @return
       */
      Person get(int id);

      /**
       * 获取所有的Person
       * @return List集合
       */
      List<Person> getAll();

      /**
       * 分页查询显示
       * @param firstResult 第一条记录从哪里开始
       * @param maxResults 最多包含多少条记录
       * @return 该返回值包含了一个表的总记录数和一个List结果集
       */
       QueryResult query(int firstResult,int maxResults);

 }

IPerson.java

三、com.mypro.util包

1、定一个HibernateUtils工具类，该类封装了SessionFactory对象

 package com.mypro.util;

 import org.hibernate.Session;
 import org.hibernate.SessionFactory;
 import org.hibernate.cfg.Configuration;

 public class HibernateUtils {

     //声明一个静态变量，并在静态代码块中给该对象赋值
     private static SessionFactory sessionFactory;
     static{
         /*方式一
         Configuration cfg=new Configuration();
         cfg.configure("hibernate.cfg.xml"); //加载指定位置的配置
         sessionFactory=cfg.buildSessionFactory();*/

         /*方式二：当hibernate的主配置文件名称为hibernate.cfg.xml时，且该文件在类的根目录下时，当cfg.configure时可以省略参数
         Configuration cfg=new Configuration();
         cfg.configure(); //加载默认配置文件
         sessionFactory=cfg.buildSessionFactory();*/

         //方法三 ：由于cfg.configure()方法返回的依然是Configuration对象，所以该方法更进一步精简为
         sessionFactory=new Configuration()
             .configure()
             .buildSessionFactory();
     }

     /**
      * 获取SessionFactory工厂
      * @return
      */
     public static SessionFactory getSessionFactory(){
         return sessionFactory;
     }

     /**
      * 获取返回一个打开的Session
      * @return
      */
     public static Session openSession(){
         return sessionFactory.openSession();
     }
 }

HibernateUtils.java

四、com.mypro.dao.impl包

该包主要实现com.mypro.dao下的接口

1、实现IPerson接口

 package com.mypro.dao.impl;

 import java.util.List;

 import org.hibernate.Query;
 import org.hibernate.Session;
 import org.hibernate.Transaction;

 import com.mypro.dao.IPerson;
 import com.mypro.domain.Person;
 import com.mypro.domain.QueryResult;
 import com.mypro.util.HibernateUtils;

 public class PersonImpl implements IPerson {

     @Override
     public void add(Person person) {
         Session session=null;
         Transaction tran=null;
         try{
             session=HibernateUtils.openSession();
             tran=session.beginTransaction();
             session.save(person);
             tran.commit();
         }catch(RuntimeException e){
             if(tran!=null)
                 tran.rollback();
             throw e;
         }finally{
             if(session!=null)
                 session.close();
         }

     }

     @Override
     public void delete(int id) {
         Session session=null;
         Transaction tran=null;
         try{
             session=HibernateUtils.openSession();
             tran=session.beginTransaction();
             Person person=session.get(Person.class, id);
             session.delete(person);
             tran.commit();
         }catch(RuntimeException e){
             if(tran!=null)
                 tran.rollback();
             throw e;
         }finally{
             if(session!=null)
                 session.close();
         }

     }

     @Override
     public void update(Person person) {
         Session session=null;
         Transaction tran=null;
         try{
             session=HibernateUtils.openSession();
             tran=session.beginTransaction();
             session.update(person);
             tran.commit();
         }catch(RuntimeException e){
             if(tran!=null)
                 tran.rollback();
             throw e;
         }finally{
             if(session!=null)
                 session.close();
         }

     }

     @Override
     public Person get(int id) {
         Session session=null;
         try{
             session=HibernateUtils.openSession();
             return session.get(Person.class, id);
         }catch(RuntimeException e){
             throw e;
         }finally{
             if(session!=null)
                 session.close();
         }
     }

     @Override
     public List<Person> getAll() {
         Session session=null;
         try{
             session=HibernateUtils.openSession();
             /*方式一
             Query query= session.createQuery("FROM persion",,Person.class);
             return query.list(); */
             //方式二
             return session.createQuery("from Person").list();    //注意HSL方式要求Person为类名，属性名和类名必须完全一致，其它关键字可忽略大小写
         }catch(RuntimeException e){
             throw e;
         }finally{
             if(session!=null)
                 session.close();
         }
     }

     @Override
     public QueryResult query(int firstResult, int maxResults) {
         Session session=null;
         try{
             session=HibernateUtils.openSession();
             long count= (long)session.createQuery("SELECT COUNT(*) FROM Person").uniqueResult();
             List list=session.createQuery("FROM Person")//
                     .setFirstResult(firstResult)//
                     .setMaxResults(maxResults)
                     .list();
             return new QueryResult(count, list);
         }catch(RuntimeException e){
             throw e;
         }finally{
             if(session!=null)
                 session.close();
         }
     }

 }

PersonImpl.java

五、配置hibernate主配置文件

 <?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 name="mysqldb">

     <!-- 配置方言：选择数据库类型 -->
     <property name="dialect">org.hibernate.dialect.MySQLDialect</property>

     <!-- 配置数据库连接信息 -->
     <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
     <property name="connection.url">jdbc:mysql:///test?characterEncoding=utf8</property>
     <property name="connection.username">root</property>
     <property name="connection.password">123456</property>

     <!-- 允许显示sql语句 -->
     <property name="show_sql">true</property>
     <!-- 导入映射文件 -->
     <mapping resource="com/mypro/domain/Person.hbm.xml" />
 </session-factory>
 </hibernate-configuration>

hibernate.cfg.xml

六、代码测试

1、在com.mypro.test包下PersonTest.java

 package com.mypro.test;

 import java.util.List;

 import org.junit.Test;

 import com.mypro.dao.IPerson;
 import com.mypro.dao.impl.PersonImpl;
 import com.mypro.domain.Person;
 import com.mypro.domain.QueryResult;

 public class PersonTest {

     private static IPerson personDao=new PersonImpl();

     @Test
     public void add(){
         Person person=new Person();
         person.setName("zhh");
         person.setAge(26);
         person.setGender("女");
         personDao.add(person);
     }

     @Test
     public void get(){
         Person person=personDao.get(37);
         System.out.println(person);
     }

     @Test
     public void update(){
         Person person=personDao.get(37);
         person.setAge(25);
         personDao.update(person);
     }

     @Test
     public void getAll(){
         List<Person> list=personDao.getAll();
         for (Person person : list) {
             System.out.println(person);
         }
     }

     @Test
     public void query(){
         QueryResult qr= personDao.query(2, 10);
         System.out.println("总记录数："+qr.getCount());
         List<Person> list=qr.getList();
         for (Person person : list) {
             System.out.println(person);
         }
     }

     @Test
     public void delete(){
         personDao.delete(37);
     }
 }

PersonTest.java