Hibernate单表映射学习笔记之一——hibernalnate开发环境配置

Posted 云中志

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  1、什么是ORM?

  Object/Relationship Mapping:对象/关系映射

  2、写SQL语句不好之处:

  (1)不同数据库使用的SQL语法不同(PL/SQL、T/SQL)

  (2)同样的功能在不同的数据库中有不同的实现方式(分页SQL)

  (3)过分依赖SQL语句对程序的移植和拓展不利

  3、Hibernate

  (1)ORM框架技术

  (2)对JDBC进行了非常轻量的对象封装

  

  4、其他ORM框架技术

  (1)Mybatis(前身为iBatis)

  (2)Toplink(现为Oracle As Toplink)

  (3)EJB:本身就是JAVAEE规范

  5、所需工具:

  (1) Hibernate 核心包;

  (2) Hibernate eclipse plugin;

  6、创建Hibernate项目步骤:

  (1)导入核心包及数据库驱动:

  

  (2)创建配置文件;

  

<?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>
        <property name="connection.username">root</property>
        <property name="connection.password">root</property>
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="connection.url">jdbc:mysql:///hibernate?useUnicode=true&amp;characterEncoding=UTF-8</property>
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
        <property name="show_sql">true</property>
        <property name="format_sql">true</property>
        <property name="hbm2ddl.auto">create</property>
        <mapping resource="Student.hbm.xml"/>
    </session-factory>
</hibernate-configuration>

 

  (3)创建持久化类;

package hibernate001;
//学生类

import java.util.Date;
public class Student{
//持久化类的设计原则
	//1、公有的类
	//2、提供共有的不带参数的默认的构造方法
	//3、属性私有
	//4、属性setter/getter封装
	
	private int sid;//学号
	private String name;//姓名
	private String gender;//性别
	private Date birthday;//出生日期
	private String address;//地址

	
	public Student(){
		
	}


	public Student(int sid, String name, String gender, Date birthday, String address) {
		this.sid = sid;
		this.name = name;
		this.gender = gender;
		this.birthday = birthday;
		this.address = address;
	}


	public int getSid() {
		return sid;
	}


	public void setSid(int sid) {
		this.sid = sid;
	}


	public String getName() {
		return name;
	}


	public void setName(String name) {
		this.name = name;
	}


	public String getGender() {
		return gender;
	}


	public void setGender(String gender) {
		this.gender = gender;
	}


	public Date getBirthday() {
		return birthday;
	}


	public void setBirthday(Date birthday) {
		this.birthday = birthday;
	}


	public String getAddress() {
		return address;
	}


	public void setAddress(String address) {
		this.address = address;
	}


	@Override
	public String toString() {
		return "Student [sid=" + sid + ", name=" + name + ", gender=" + gender + ", birthday=" + birthday + ", address="
				+ address + "]";
	}
	
}

  

  (4)创建对象——关系映射文件;

<?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 2017-4-14 17:17:44 by Hibernate Tools 3.5.0.Final -->
<hibernate-mapping>
    <class name="hibernate001.Student" table="STUDENT">
        <id name="sid" type="int">
            <column name="SID" />
            <generator class="assigned" />
        </id>
        <property name="name" type="java.lang.String">
            <column name="NAME" />
        </property>
        <property name="gender" type="java.lang.String">
            <column name="GENDER" />
        </property>
        <property name="birthday" type="java.util.Date">
            <column name="BIRTHDAY" />
        </property>
        <property name="address" type="java.lang.String">
            <column name="ADDRESS" />
        </property>
    </class>
</hibernate-mapping>

 

  (5)通过Hibernate API编写访问数据库代码:

  我用的是Juntil4这个测试类

package hibernate001;

import org.hibernate.Transaction;
import java.util.Date;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

//测试类
public class StudentTest {
	
	private SessionFactory sessionFactory;
	private Session session;
	private Transaction transaction; 
	@Before
	public void init(){
		//穿件配置对象
		Configuration configuration = new Configuration().configure();
		//创建服务注册对象
		ServiceRegistry serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties()).buildServiceRegistry();
		//创建会话对象
		sessionFactory = configuration.buildSessionFactory(serviceRegistry);
		//打开会话
		session = sessionFactory.openSession();
		//打开事务
		transaction = session.beginTransaction();
	}
	@After
	public void destory(){
		transaction.commit();//提交事务
		session.close();//关闭会话
		sessionFactory.close();//关闭会话工厂
	}
	@Test
	public void testSavestudent(){
		Student s1 = new Student(1, "张三丰", "男", new Date(), "武当山");
		session.save(s1);
	}
}

  

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