第一个Hibernate项目的搭建实例教程。hibernate增删查改数据库实例。建立类与表的映射文件.hbm.xml……
建立一个Java项目，加入如下jar文件：
* HIBERNATE_HOME/hibernate3.jar
* HIBERNATE_HOME/lib/*.jar
* 数据库驱动
复制hibernate.cfg.xml和log4j.properties到项目的src目录下，这两个文件位于
* HIBERNATE_HOME/etc/
建立JavaBean对象(实体类)
Javabean对象用来映射数据库一条记录。实例代码如下：
package po;
//对应数据库T_CUSTOMER中的一条记录,用JavaBean规范编写
public class Customer {
private String account;
private String password;
private String cname;
private double cbalance;
public Customer(){}
public Customer(String account,String password,String cname,double cbalance){
this.account = account;
this.password = password;
this.cname = cname;
this.cbalance = cbalance;
}
public String getAccount() {
return account;
}
public void setAccount(String account) {
this.account = account;
}
public double getCbalance() {
return cbalance;
}
public void setCbalance(double cbalance) {
this.cbalance = cbalance;
}
public String getCname() {
return cname;
}
public void setCname(String cname) {
this.cname = cname;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
}
建立类与表的映射文件（.hbm.xml）
<?xml version=”1.0″?>
<!DOCTYPE hibernate-mapping PUBLIC
“-//Hibernate/Hibernate Mapping DTD 3.0//EN”
“http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd”>
<hibernate-mapping>
<class name=”po.Customer” table=”T_CUSTOMER”> <!– 类和表对应 –>
<id name=”account” column=”ACCOUNT”> <!– 主键 –>
<!– 主键生成策略,assigned表示由用户赋值 –>
<generator/>
</id>
<property name=”password” column=”PASSWORD”/>
<property name=”cname” column=”CNAME”/>
<property name=”cbalance” column=”CBALANCE”/>
</class>
</hibernate-mapping>
创建hibernate配置文件(hibernate.cfg.xml)
hibernate.cfg.xml是hibernate的配置信息，为了方便跟踪sql执行，在hibernate.cfg.xml文件中加入<property name=”hibernate.show_sql”>true</property>，例如：
| <?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.username”>scott</property> <property name=”connection.url”>jdbc:odbc:School</property> <property name=”dialect”> org.hibernate.dialect.Oracle9Dialect </property> <property name=”connection.password”>tiger</property> <property name=”connection.driver_class”> sun.jdbc.odbc.JdbcOdbcDriver </property> <property name=”show_sql”>true</property> <mapping resource=”po/Customer.hbm.xml” /> </session-factory> </hibernate-configuration> |
编写hbm2ddl工具类
编写hbm2ddl工具类，将实体类生成数据库表，代码如下：
public class ExportDB {
public static void main(String[] args) {
//读取hibernate.cfg.xml文件
Configuration cfg = new Configuration().configure();
SchemaExport export = new SchemaExport(cfg);
export.create(true, true);
}
}
CRUD操作
Hibernate添加数据库信息
//第一步，读取Hibernate配置文件
Configuration conf = new Configuration().configure();
//第二步,Hibernate操作要使用Session来完成，Session由SessionFactory管理，
//生成SessionFactory
SessionFactory sf = conf.buildSessionFactory();
//第三步:打开Session,Session的事务不是自动提交的
Session session = sf.openSession();
Customer cus = new Customer(“222″,”222″,”张三”,4000);
Transaction tran = session.beginTransaction();
session.save(cus);
tran.commit();
Hibernate删除数据库信息
Configuration conf = new Configuration().configure();
SessionFactory sf = conf.buildSessionFactory();
Session session = sf.openSession();
Customer cus = new Customer();
session.load(cus, “111″);
Transaction tran = session.beginTransaction();
session.delete(cus);
tran.commit();
Hibernate更新数据库信息
Configuration conf = new Configuration().configure();
SessionFactory sf = conf.buildSessionFactory();
Session session = sf.openSession();
Customer cus = new Customer();
session.load(cus, “111″);
cus.setCbalance(cus.getCbalance() + 1000);
Transaction tran = session.beginTransaction();
session.update(cus);
tran.commit();
Hibernate查询数据库信息
Configuration conf = new Configuration().configure();
SessionFactory sf = conf.buildSessionFactory();
Session session = sf.openSession();
Customer cus = new Customer();
session.load(cus, “111″);
System.out.println(cus.getAccount());
System.out.println(cus.getPassword());
System.out.println(cus.getCname());
System.out.println(cus.getCbalance());