首先下载好hibernate包
如果运行之后出现数据库连接错误 则重新把jar包位置放在web-inf的lib下面再addbulidpath
第一步:创建实体类
Hibernate要求实体类必须提供一个不带参数的默认构造方法。因为程序运行时,Hibernate会运用java的反射机制,创建实体类的实例。
package hibernateDemo; public class User { private int id; private String name; private String password; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } }
第二步:在MySql中创建对应的数据表
CREATE DATABASE hibernate; USE hibernate; CREATE TABLE USER( id INT PRIMARY KEY AUTO_INCREMENT, name VARCHAR(50), password VARCHAR(50) );
第三步:创建Hibernate的配置文件,放在src目录下,文件名为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="connection.driver_class">com.mysql.jdbc.Driver</property> <property name="connection.url">jdbc:mysql://127.0.0.1:3306/hibernate_database</property> <property name="connection.username">root</property> <property name="connection.password">admin</property> <!-- 配置数据库方言 --> <property name="dialect">org.hibernate.dialect.MySQLDialect</property> <!-- 全局 --> <property name="hibernate.hbm2ddl.auto">update</property> <property name="show_sql">true</property><!-- //显示sql语句 --> <property name="format_sql">true</property><!-- //格式化sql语句 --> <!-- 没有这句话不会改变数据库 --> <property name="hibernate.connection.autocommit">true</property> <mapping resource="hibernateDemo/User.hbm.xml"/><!-- 映射信息 --> </session-factory> </hibernate-configuration>
第四步:创建对象-关系映射文件 该文件应该和实体类在同一目录下。命名规则为 实体类名.hbm.xml 例如User.hbm.xml
<?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="hibernateDemo.User" table="user"> <id name="id" column="id"> <generator class="native"></generator> </id> <property name="name" column="name"></property> <property name="password" column="password"></property> </class> </hibernate-mapping>
第五步:测试类
package test; import hibernateDemo.User; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration; import org.junit.Test; import org.hibernate.Transaction; public class test { Transaction tx; @Test public void test1() { //读取配置文件 Configuration conf=new Configuration().configure(); //根据配置创建factory SessionFactory sessionfactory=conf.buildSessionFactory(); //获得操作数据库的session对象 Session session=sessionfactory.openSession(); //创建对象新增 User u=new User(); u.setName("liu三"); u.setPassword("123456"); //将对象保存到数据库 session.save(u); // 查询方式1 // User user = (User)session.get(User.class, 2); // System.out.println(user.getName()); //修改 /* User user = (User)session.get(User.class, 2); user.setName("李王二"); Transaction tx=session.beginTransaction(); session.update(user); tx.commit();*/ //删除 /* User user = (User)session.get(User.class, 4); Transaction tx=session.beginTransaction(); session.delete(user); tx.commit();*/ //关闭资源 session.close(); sessionfactory.close(); } }