hibernate-----单向多对一
一、项目用到的包
下载地址：https://download.****.net/download/wwt819635881/11095021
二、新建一个java项目
在项目中新建一个lib文件夹，把要用到的包粘贴进去，右键build path------ add to build path
三、在src建立两个包，一个Entity,一个Test
目录结构：
四、实体层代码
Customer.java
package Entity;
public class Customer {
private String id; //客户id
private String userName; //用户名
private String pwd; //用户密码
private String address; //用户地址
public Customer() {
super();
}
public Customer(String userName, String pwd, String address) {
this.userName = userName;
this.pwd = pwd;
this.address = address;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getUserName() {
return userName;
}
public void setUserName(String userName) {
this.userName = userName;
}
public String getPwd() {
return pwd;
}
public void setPwd(String pwd) {
this.pwd = pwd;
}
public String getAddress() {
return address;
}
public void setAddress(String address) {
this.address = address;
}
}
Order.java
package Entity;
import java.util.Date;
public class Order {
private String id; //订单ID
private String OrderNo; //订单编号
private Date date; //订单日期
private Customer customer; //客户类型变量
public Order() {
super();
}
public Order(String orderNo, Date date, Customer customer) {
this.OrderNo = orderNo;
this.date = date;
this.customer = customer;
}
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
public String getOrderNo() {
return OrderNo;
}
public void setOrderNo(String orderNo) {
this.OrderNo = orderNo;
}
public Date getDate() {
return date;
}
public void setDate(Date date) {
this.date = date;
}
public Customer getCustomer() {
return customer;
}
public void setCustomer(Customer customer) {
this.customer = customer;
}
}
Customer.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 package="Entity">
<class name="Entity.Customer" table="CUSTOMER">
<!-- 给表提供一个标识，也就是主键，同样需要提供生成策略，是数据库自增，还是手动增 -->
<id name="id" column="ID">
<!-- 生成器，自动生成主键 -->
<generator class="uuid"/>
</id>
<!-- 该表的其它字段，默认列名为name的属性值，也可以用column属性对字段进行重命名 -->
<!-- 用户名 -->
<property name="userName" column="USERNAME" type="string" not-null="true"/>
<!-- 用户密码 -->
<property name="pwd" column="PWD" type="string" not-null="true"/>
<!-- 用户地址-->
<property name="address" column="ADDRESS" type="string"/>
</class>
</hibernate-mapping>
Order.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 package="Entity">
<class name="Entity.Order" table="ORDERS">
<!-- 给表提供一个标识，也就是主键，同样需要提供生成策略，是数据库自增，还是手动增 -->
<id name="id" column="ID">
<!-- 生成器，自动生成主键 -->
<generator class="uuid"/>
</id>
<!-- 该表的其它字段，默认列名为name的属性值，也可以用column属性对字段进行重命名 -->
<!-- 订单编号 -->
<property name="orderNo" column="ORDERNO" type="string"/>
<!-- 下单日期 -->
<property name="date" column="ORDERDATE" type="timestamp"/>
<!-- 单向关联N-1-->
<many-to-one name="customer" column="CUSTOMER_ID" class="Customer"/>
</class>
</hibernate-mapping>
五、配置代码
hibernate.cfg.xml 这个xml文件一定是要在项目直接右键建立，别创建在src里！！！
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<!-- mysql数据库连接驱动 -->
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<!-- 数据库连接地址 -->
<property name="hibernate.connection.url">jdbc:mysql://127.0.0.1/HibernateTest2?useUnicode=true&characterEncoding=UTF8</property>
<!-- 连接数据库用户名和密码 -->
<property name="hibernate.connection.username">root</property>
<property name="hibernate.connection.password">1234</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>
<!-- 数据源(DBCP)：数据库连接池 -->
<property name="hibernate.connection.provider_class">org.hibernate.c3p0.internal.C3P0ConnectionProvider</property>
<!-- 配置当前session上下文 保证同一个线程中获取的session是同一个-->
<property name="hibernate.current_session_context_class">thread</property>
<!-- 自动建表 里面的值也可以是create，但是每次都会新建一个表，影响效率，update在原有的表上面添加信息 -->
<property name="hibernate.hbm2ddl.auto">update</property>
<!-- 控制台显示sql语句 -->
<property name="show_sql">true</property>
<!-- sql语句格式化输出 -->
<property name="format_sql">true</property>
<mapping resource="Entity/Order.hbm.xml"/>
<mapping resource="Entity/Customer.hbm.xml"/>
</session-factory>
</hibernate-configuration>六、测试类代码
CreateTable.java
package Test;
import org.hibernate.cfg.Configuration;
import org.hibernate.tool.hbm2ddl.SchemaExport;
//将hbm生成ddl
public class CreatTable {
public static void main(String[] args) {
//默认读取hibernate.cfg.xml文件
Configuration cfg = new Configuration().configure();
//Commandline tool to export table schema to the database. This class may also be called from inside an application.
SchemaExport export = new SchemaExport(cfg);
//将ddl打印到控制台，输入到数据库
export.create(true, true);
}
}
输入这段代码后，右键run as JavaApplication
就可以看到navicat已经帮你建好表了，当然前提是记得在代码运行前在navicat建立你的数据库。
Client.java
package Test;
import org.hibernate.Transaction;
import java.util.Date;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import Entity.Customer;
import Entity.Order;
public class Client {
@SuppressWarnings("deprecation")
public static void main(String[] args) {
Configuration config = new Configuration().configure();//加载配置文件hibernate.cfg.xml
//根据配置文件创建会话工厂
SessionFactory factory = config.buildSessionFactory();
//根据会话工厂创建会话
Session session = factory.getCurrentSession();
//创建一个事物对象
Transaction tx = session.beginTransaction();
//new 一个订单对象
Customer customer=new Customer("李白","666","广东广州");
session.save(customer);
//添加两条记录
Order order=new Order("1",new Date(),customer);
Order order2=new Order("2",new Date(),customer);
//将对象持久化到数据表中
session.save(order);
session.save(order2);
//提交事务
tx.commit();
//关闭会话
/*session.close();*/
//关闭工厂
factory.close();
}
}
这个时候我们再右键run as-----run on Java Application
就可以看到控制台输出sql语句
回到Navicat就可以看到数据显示了。