1.Hibernate入门

一、Hibernate必须包（3.2）
     hibernate3.jar：Hibernate的核心库
     cglib-2.1.3.jar： Hibernate用它来实现PO字节码的动态生成，非常核心的库

     asm.jar:cglib所使用的库
     asm-attrs.jar： cglib所使用的库
     dom4j-1.6.1.jar： Hibernate用它来读写配置文件
     commons-logging-1.0.4.jar：用于日志管理
     commons-collections-2.1.1.jar： 包含了一些Apache开发的集合类，功能比java.util.*强大
     antlr-2.7.6.jar：是语法分析生成器

 

二、配置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>
		<property name="dialect">
			org.hibernate.dialect.MySQLDialect
		</property>
		<property name="connection.url">
			jdbc:mysql://localhost:3306/jpa?useUnicode=true&amp;characterEncoding=UTF-8
		</property>
		<property name="connection.username">root</property>
		<property name="connection.password">root</property>
		<property name="connection.driver_class">
			com.mysql.jdbc.Driver
		</property>

		<!-- hibernate属性 -->
		<!-- 是否显示执行的sql语句 -->
		<property name="show_sql">true</property>
		<!-- 显示执行的sql语句是否格式化 -->
		<property name="format_sql">true</property>
		<!-- 根据配置文件创建表 -->
		<property name="hbm2ddl.auto">update</property>
		
		<mapping resource="com/tao/hibernate/Student.hbm.xml"/>

	</session-factory>

</hibernate-configuration>

 

三、配置ORM映射

1.创建java类

package com.tao.hibernate;

import java.io.Serializable;

@SuppressWarnings("serial")
public class Student implements Serializable {
	private Integer id;
	private String name;

	public Student() {
		super();
	}

	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;
	}
}

 2.配置表映射文件

<?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>
	<class name="com.tao.hibernate.Student" table="student" schema="jpa">
		<id name="id" type="java.lang.Integer" column="id">
			<generator class="identity" />
		</id>
		<property name="name" type="java.lang.String">
			<column name="name" length="16" />
		</property>
	</class>
</hibernate-mapping>

 注：映射文件已经在二中加入了。如果没有加入，自己手动加入。

四、数据操作类

package com.tao.hibernate;

import java.util.List;

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

public class StudentDAO {
	private Session session = null;

	public StudentDAO() {
                //创建一个Configuration对象，此时Hibernate会默认加载classpath中的配置文件hibernate.properties
                //configura()方法：用于告诉Hibernate加载hibernate.cfg.xml文件。

		Configuration config = new Configuration().configure();
		SessionFactory factory = config.buildSessionFactory();
		session = factory.openSession();
	}

	public void save(Student student) {
		Transaction tran = session.getTransaction();
		tran.begin();
		session.save(student);
		tran.commit();
	}

	public void update(Student student) {
		Transaction tran = session.beginTransaction();
		tran.begin();
		session.update(student);
		tran.commit();
	}

	public void delete(Integer id) {
		String hql = "delete from Student o where o.id = ?";
		Transaction tran = session.beginTransaction();
		tran.begin();
		Query query = session.createQuery(hql);
		query.setParameter(0, id);
		query.executeUpdate();
		tran.commit();
	}

	@SuppressWarnings("unchecked")
	public Student getModel(Integer id) {
		String hql = "from Student o where id = :id";
		Query query = session.createQuery(hql);
		query.setParameter("id", id);
		List list = query.list();
		if (list != null && list.size() == 1) {
			return (Student) list.get(0);
		} else {
			return null;
		}
	}

	@SuppressWarnings("unchecked")
	public List getPagination(int maxResults, int firstResult) {
		String hql = "from Student o";
		Query query = session.createQuery(hql);
		query.setFirstResult(firstResult);
		query.setMaxResults(maxResults);
		return query.list();
	}
}

 

五、测试代码类

package com.tao.hibernate;

import java.util.List;

public class Test {

	@SuppressWarnings("unchecked")
	public static void main(String[] args) {

		StudentDAO dao = new StudentDAO();
		// 添加
		// for (int i = 0; i < 10; i++) {
		// Student student = new Student();
		// student.setName("Tao" + i);
		// dao.save(student);
		// }

		// 删除
		// dao.delete(2);

		// 修改
		// Student student = new Student();
		// student.setId(4);
		// dao.update(student);

		// 单个查询
		// Student s = dao.getModel(4);
		// System.out.println(s.getName());

		// 分布查询
		List list = dao.getPagination(4, 1);
		for (int i = 0; i < list.size(); i++) {
			Student std = (Student) list.get(i);
			System.out.println(std.getName());
		}
	}

}