hibernate的 Annotation版Hello world

最新推荐文章于 2021-02-16 14:50:08 发布

原创最新推荐文章于 2021-02-16 14:50:08 发布 · 711 阅读

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本文详细介绍了如何使用注解创建教师实体类，并配置Hibernate进行持久化操作，包括连接数据库设置、实体类定义及映射配置。

需要引入的包：hibernate-commons-annotations-4.0.4.Final.jar

由于我使用的是：hibernate-release-4.3.5.Final，在required目录下已经有了。

bean：

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="teacher")
public class Teacher {
	private int id;
	private String name;
	private String title;
	@Id
	public int getId() {
		return id;
	}
	
	public void setId(int id) {
		this.id = id;
	}
	@Column(name="name")
	public String getName() {
		return name;
	}
	
	public void setName(String name) {
		this.name = name;
	}
	@Column(name="title")
	public String getTitle() {
		return title;
	}
	
	public void setTitle(String title) {
		this.title = title;
	}
	
}

对应的hibernate.cfg.xml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>

        <!-- Database connection settings -->
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="connection.url">jdbc:mysql://localhost/hibernate</property>
        <property name="connection.username"></property>
        <property name="connection.password"></property>

        <!-- JDBC connection pool (use the built-in) -->
        <!-- 
        <property name="connection.pool_size">1</property>
		 -->
        <!-- SQL dialect -->
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>

        <!-- Enable Hibernate's automatic session context management -->
        <property name="current_session_context_class">thread</property>

        <!-- Disable the second-level cache  -->
        <property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property>

        <!-- Echo all executed SQL to stdout -->
        <property name="show_sql">true</property>

        <!-- Drop and re-create the database schema on startup -->
        <!-- 
        <property name="hbm2ddl.auto">update</property>
 		-->
        <mapping resource="com/hibernate/model/Student.hbm.xml"/>
		<mapping class="com.hibernate.model.Teacher"/>
    </session-factory>

</hibernate-configuration>

测试类：

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

import com.huxing.hibernate.model.Student;
import com.huxing.hibernate.model.Teacher;

public class StudentTest {
	public static void main(String[] args) {
		Student a = new Student();
		a.setId(123);
		a.setAge(32);
		a.setName("hello hibernate!");
		
		Teacher tea = new Teacher();
		tea.setId(4);
		tea.setName("mysql");
		tea.setTitle("high");
		Configuration cfg = new AnnotationConfiguration();
		SessionFactory cf = cfg.configure().buildSessionFactory();
		Session session = cf.openSession();
		session.beginTransaction();
		session.save(tea);
		session.getTransaction().commit();
		session.close();
		cf.close();
	}
}

注意：我代码省略了包路径。

其他方面：1.注解可以加在属性上，也可以加在get方法上。

2.注解的mapping和xml配置的xml的不同！一个是resource,一个是class。