[學習小結]Hibernate的Helloworld

①創建持久化 Java 類

import java.sql.Blob;
import java.util.Date;

public class News {
	
	private Integer id; //field
	private String title;
	private String author;
	
	private String desc;
	
	//使用 title + "," + content 可以來描述當前的 News 記錄. 
	//即 title + "," + content 可以作爲 News 的 desc 屬性值
	
	private String content;
	
	private Blob picture;
	
	public Blob getPicture() {
		return picture;
	}

	public void setPicture(Blob picture) {
		this.picture = picture;
	}

	public String getContent() {
		return content;
	}

	public void setContent(String content) {
		this.content = content;
	}
	
	public String getDesc() {
		return desc;
	}

	public void setDesc(String desc) {
		this.desc = desc;
	}



	private Date date;

	public Integer getId() { //property
		return id;
	}

	public void setId(Integer id) {
		this.id = id;
	}

	public String getTitle() {
		return title;
	}

	public void setTitle(String title) {
		this.title = title;
	}

	public String getAuthor() {
		return author;
	}

	public void setAuthor(String author) {
		this.author = author;
	}

	public Date getDate() {
		return date;
	}

	public void setDate(Date date) {
		this.date = date;
	}

	public News(String title, String author, Date date) {
		super();
		this.title = title;
		this.author = author;
		this.date = date;
	}
	
	public News() {
		// TODO Auto-generated constructor stub
	}

	@Override
	public String toString() {
		return "News [id=" + id + ", title=" + title + ", author=" + author
				+ ", date=" + date + "]";
	}
	
	
	
}

②創建對象-關係映射文件

News.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">

<hibernate-mapping package="com.atguigu.hibernate.helloworld">

    <class name="News" table="NEWS" dynamic-insert="true">
    	
        <id name="id" type="java.lang.Integer">
            <column name="ID" />
            <!-- 指定主鍵的生成方式, native: 使用數據庫本地方式 -->
            <generator class="native" />
        </id>
    
        <property name="title" not-null="true" unique="true"
        	index="news_index" length="50"
        	type="java.lang.String" column="TITLE" >
        </property>
        
        <property name="author" type="java.lang.String"
        	index="news_index">
            <column name="AUTHOR" />
        </property>
        
        <property name="date" type="date">
            <column name="DATE" />
        </property>
        
        <property name="desc" 
        	formula="(SELECT concat(title, ',', author) FROM NEWS n WHERE n.id = id)"></property>
		
		<property name="content">
			<column name="CONTENT" sql-type="text"></column>
		</property>
		
		<property name="picture" column="PICTURE" type="blob"></property>
		
    </class>
    
</hibernate-mapping>

③創建 Hibernate配置文件

hibernate.cfg.xml：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
		"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
		"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
	<session-factory>
    
		<!-- 配置連接數據庫的基本信息 -->
		<property name="connection.username">root</property>
		<property name="connection.password"></property>
		<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
		<property name="connection.url">jdbc:mysql:///hibernate1</property>
		
		<!-- 配置 hibernate 的基本信息 -->
		<!-- hibernate 所使用的數據庫方言 -->
		<property name="dialect">org.hibernate.dialect.MySQLInnoDBDialect</property>		
		
		<!-- 執行操作時是否在控制檯打印 SQL -->
		<property name="show_sql">true</property>
	
		<!-- 是否對 SQL 進行格式化 -->
		<property name="format_sql">true</property>
	
		<!-- 指定自動生成數據表的策略 -->
		<property name="hbm2ddl.auto">update</property>
		
		<!-- 指定關聯的 .hbm.xml 文件 -->
		<mapping resource="com/atguigu/hibernate/helloworld/News.hbm.xml"/>
	
	</session-factory>

</hibernate-configuration>

④Helloworld的測試用例

import java.sql.Date;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;
import org.junit.Test;

public class HibernateTest {

	@Test
	public void test() {
		
		System.out.println("test...");
		
		//1. 創建一個 SessionFactory 對象
		SessionFactory sessionFactory = null;
		
		//1). 創建 Configuration 對象: 對應 hibernate 的基本配置信息和 對象關係映射信息
		Configuration configuration = new Configuration().configure();
		
		//4.0 之前這樣創建
//		sessionFactory = configuration.buildSessionFactory();
		
		//2). 創建一個 ServiceRegistry 對象: hibernate 4.x 新添加的對象
		//hibernate 的任何配置和服務都需要在該對象中註冊後纔能有效.
		ServiceRegistry serviceRegistry = 
				new ServiceRegistryBuilder().applySettings(configuration.getProperties())
				                            .buildServiceRegistry();
		
		//3).
		sessionFactory = configuration.buildSessionFactory(serviceRegistry);
		
		//2. 創建一個 Session 對象
		Session session = sessionFactory.openSession();
		
		//3. 開啓事務
		Transaction transaction = session.beginTransaction();
		
		//4. 執行保存操作
		News news = new News("Java12345", "ATGUIGU", new Date(new java.util.Date().getTime()));
		session.save(news);
		
		//5. 提交事務 
		transaction.commit();
		
		//6. 關閉 Session
		session.close();
		
		//7. 關閉 SessionFactory 對象
		sessionFactory.close();
	}
	
}

⑤查看數據庫是否創建成功