Hibernate框架的搭建和一个简单的实例

Hibernate是一个支持对JDBC进行封装的框架，实现了对底层数据库访问的封装。非常适合使用和开发。首先需要下载Hibernate，可以在这个网站下载最新包。http://www.hibernate.org/然后打开他的目录结构，将lib目录下的required目录下的包全部导入到工程中去，这个是hibernate运行所必须的最少的包。然后写一个Bean，将需要储存到数据库中的变量封装成Bean。为了让Hibernate识别这个bean，需要一个配置文件，这里起名叫User.hbm.xml。先看一下User的代码和User.hbm.xml的代码

package com.bird.domain;import java.util.Date;public class User {private int id;private String name;private Date birthday;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 Date getBirthday() {return birthday;}public void setBirthday(Date birthday) {this.birthday = birthday;}}

<?xml version="1.0" ?>  
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"  "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">  
<hibernate-mapping package="com.bird.domain">  <class name="User">  <id name="id">  <generator class="native"/>  </id>  <property name="name"/>  <property name="birthday"/>  </class>  </hibernate-mapping>

然后需要一个Hibernate的配置文件,这个文件的例子可以再Hibenate解压目录的project里面的ect目录里面找到。更加详细的配置选项和要求可以参考hibernate.properties.template这个文件.

<?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>  <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>  <property name="hibernate.connection.url">jdbc:mysql:///test</property>  <property name="hibernate.connection.username">root</property>  <property name="hibernate.connection.password">mysql</property>  <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>  <property name="hibernate.hbm2ddl.auto">update</property>  <mapping resource="com/bird/domain/User.hbm.xml"/>  </session-factory>  
</hibernate-configuration>

<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>这句话的意思是指定你使用的数据库的方言.

<property name="hibernate.hbm2ddl.auto">update</property>这句话的意思是自动创建或者更改数据库里面的表或者表的内容结构

<mapping resource="com/bird/domain/User.hbm.xml"/>这句话的意思是要求装载这个类映射文件

下面就可以运行这个了，记住，别忘了导入Mysql的Connection的Jar包。

package com.bird.hibernate.test;  import java.util.Date;  import org.hibernate.Session;  
import org.hibernate.SessionFactory;  
import org.hibernate.Transaction;  
import org.hibernate.cfg.Configuration;  import com.bird.domain.User;  public class Base {  /** * @param args */  public static void main(String[] args) {  Configuration cfg = new Configuration();  cfg.configure();  @SuppressWarnings("deprecation")  SessionFactory sf = cfg.buildSessionFactory();  Session s = sf.openSession();  Transaction tx = s.beginTransaction();  User use = new User();  use.setBirthday(new Date());  use.setName("bird");  s.save(use);  tx.commit();  s.close();  }  }

运行结果如下

2012-2-28 12:12:38 org.hibernate.annotations.common.Version <clinit>  
INFO: HCANN000001: Hibernate Commons Annotations {4.0.1.Final}  
2012-2-28 12:12:38 org.hibernate.Version logVersion  
INFO: HHH000412: Hibernate Core {4.0.1.Final}  
2012-2-28 12:12:38 org.hibernate.cfg.Environment <clinit>  
INFO: HHH000206: hibernate.properties not found  
2012-2-28 12:12:38 org.hibernate.cfg.Environment buildBytecodeProvider  
INFO: HHH000021: Bytecode provider name : javassist  
2012-2-28 12:12:38 org.hibernate.cfg.Configuration configure  
INFO: HHH000043: Configuring from resource: /hibernate.cfg.xml  
2012-2-28 12:12:38 org.hibernate.cfg.Configuration getConfigurationInputStream  
INFO: HHH000040: Configuration resource: /hibernate.cfg.xml  
2012-2-28 12:12:38 org.hibernate.cfg.Configuration addResource  
INFO: HHH000221: Reading mappings from resource: com/bird/domain/User.hbm.xml  
2012-2-28 12:12:38 org.hibernate.cfg.Configuration doConfigure  
INFO: HHH000041: Configured SessionFactory: null  
2012-2-28 12:12:38 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure  
INFO: HHH000402: Using Hibernate built-in connection pool (not for production use!)  
2012-2-28 12:12:38 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure  
INFO: HHH000115: Hibernate connection pool size: 20  
2012-2-28 12:12:38 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure  
INFO: HHH000006: Autocommit mode: false  
2012-2-28 12:12:38 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure  
INFO: HHH000401: using driver [com.mysql.jdbc.Driver] at URL [jdbc:mysql:///test]  
2012-2-28 12:12:38 org.hibernate.service.jdbc.connections.internal.DriverManagerConnectionProviderImpl configure  
INFO: HHH000046: Connection properties: {user=root, password=****}  
2012-2-28 12:12:39 org.hibernate.dialect.Dialect <init>  
INFO: HHH000400: Using dialect: org.hibernate.dialect.MySQLDialect  
2012-2-28 12:12:39 org.hibernate.engine.transaction.internal.TransactionFactoryInitiator initiateService  
INFO: HHH000399: Using default transaction strategy (direct JDBC transactions)  
2012-2-28 12:12:39 org.hibernate.hql.internal.ast.ASTQueryTranslatorFactory <init>  
INFO: HHH000397: Using ASTQueryTranslatorFactory  
2012-2-28 12:12:39 org.hibernate.tool.hbm2ddl.SchemaUpdate execute  
INFO: HHH000228: Running hbm2ddl schema update  
2012-2-28 12:12:39 org.hibernate.tool.hbm2ddl.SchemaUpdate execute  
INFO: HHH000102: Fetching database metadata  
2012-2-28 12:12:39 org.hibernate.tool.hbm2ddl.SchemaUpdate execute  
INFO: HHH000396: Updating schema  
2012-2-28 12:12:39 org.hibernate.tool.hbm2ddl.TableMetadata <init>  
INFO: HHH000261: Table found: test.user  
2012-2-28 12:12:39 org.hibernate.tool.hbm2ddl.TableMetadata <init>  
INFO: HHH000037: Columns: [id, birthday, name]  
2012-2-28 12:12:39 org.hibernate.tool.hbm2ddl.TableMetadata <init>  
INFO: HHH000108: Foreign keys: []  
2012-2-28 12:12:39 org.hibernate.tool.hbm2ddl.TableMetadata <init>  
INFO: HHH000126: Indexes: [primary]  
2012-2-28 12:12:39 org.hibernate.tool.hbm2ddl.SchemaUpdate execute  
INFO: HHH000232: Schema update complete