Java-hibernate的Hello World

 hibernate 是对jdbc进行轻量级封装的  orm 框架，充当项目的持久层.

要使用 hibernate首先就需要继续配置，

引包：下载hibernate然后加入jar包

同时引入mysql的jar包

<1> 首先，手动去创建一张测试用的表，这里数据库选择mysql

CREATE TABLE `employee` (
`id` int(10) NOT NULL auto_increment,
`name` varchar(20) NOT NULL,
`email` varchar(20) NOT NULL,
`hiredate` date NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=12 DEFAULT CHARSET=latin1;

然后去手动录入数据

<2>创建我们的domain对象

建一个包，名为com.sun.domain，在包下建立一个java文件名为：Employee.java

这里面装的都是表里面的所有的字段

package com.sun.domain;

public class Employee {
	private static final long serialVersionUID = 1L;

	private Integer id;
	private String name;
	private String email;
	private java.util.Date hiredate;

	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	public String getEmail() {
		return email;
	}
	public void setEmail(String email) {
		this.email = email;
	}
	public java.util.Date getHiredate() {
		return hiredate;
	}
	public void setHiredate(java.util.Date hiredate) {
		this.hiredate = hiredate;
	}

}

　　<3>在com.sun.domain下创建对象和表的映射关系Employee.hbm.xml

<property></property> 标签下name是domain对象的属性名，<column/>是和该对像属性名相对应的表的字段名

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
	"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
	<hibernate-mapping package="com.sun.domain">
		<class name="Employee" table="employee" >
		  <id name="id" type="java.lang.Integer">
		 	<generator class="increment"></generator>
		  </id>

		  <property name="name" type="java.lang.String">
		  <column name="name" not-null="true"/>
		  </property>

		  <property name="email" type="java.lang.String">
		  <column name="email" not-null="true"/>
		  </property>

		  <property name="hiredate" type="java.util.Date">
		  <column name="hiredate" not-null="true"/>
		  </property>
		</class>
	</hibernate-mapping>

　　<4>手动配置我们的hibernate.cfg.xml文件，该文件用于配置 连接的数据库的类型，driver, 对象关系映射文件

<?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>
                <!--数据库的连接-->
		<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
		<property name="connection.url">jdbc:mysql://127.0.0.1:3306/test</property>

                <!--数据库的用户名和密码-->

                <property name="connection.username">root</property> 
                <property name="connection.password">123456</property>
		<property name="show_sql">true</property>
		<property name="dialect">org.hibernate.dialect.MySQLInnoDBDialect</property>
		<mapping resource="com/sun/domain/Employee.hbm.xml"/>
</session-factory>
</hibernate-configuration>

　　<5>写一个手动测试文件，因为hibernate是一个数据库持久层框架，所以，不只有web(j2ee)能用，se也能有使用，这里就用se进行测试

创建一个包com.sun.seriver，在下面创建一个文件Student.java

package com.sun.seriver;

import java.util.Date;

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

import com.sun.domain.Employee;

public class Student {

	public static void main(String[] args) {
		// TODO Auto-generated method stub

		Student.delEmpoyee();  //删除
//		Student.upEmpoyee();//更新
//		Student.selectEmpoyee();//查询
//		Student.addEmpoyee();//添加

	}
	private static void delEmpoyee() {
		Configuration cfg=new Configuration();
		SessionFactory sf = cfg.configure("hibernate.cfg.xml").buildSessionFactory();
		Session session = sf.openSession();
		Transaction ts=session.beginTransaction();
		Employee emp=(Employee) session.load(Employee.class, 2);
		session.delete(emp);
		ts.commit();
	}
	private static void upEmpoyee() {
		Configuration cfg=new Configuration();
		SessionFactory sf = cfg.configure("hibernate.cfg.xml").buildSessionFactory();
		Session session = sf.openSession();
		Transaction ts= session.beginTransaction();
		Employee emp=(Employee)session.load(Employee.class, 1);
		emp.setName("usagi");
		ts.commit();

	}
	//SQL SELECT
	private static void selectEmpoyee() {
		Configuration cfg=new Configuration();
		SessionFactory sf = cfg.configure("hibernate.cfg.xml").buildSessionFactory();
		Session session = sf.openSession();
		Employee emp=(Employee) session.load(Employee.class, 2);
		System.out.println(emp.getId()+" "+emp.getName()+" "+emp.getEmail());
		session.close();
	}

	//INSERT SELECT
	private static void addEmpoyee() {
		Employee s = new Employee();
		s.setName("sunzhiyan");
		s.setEmail("999@qq.com");
		s.setHiredate(new Date());

		System.out.println("test is ok");
		Configuration cfg=new Configuration();
		SessionFactory sf = cfg.configure("hibernate.cfg.xml").buildSessionFactory();
		Session session = sf.openSession();
		session.beginTransaction();
		session.save(s);
		session.getTransaction().commit();
		session.close();
		sf.close();
	}

}

　　这样，基本的hibernate的基本配置和测试就完成了