Hibernate 单向多对一

package model;
import java.io.Serializable;
//产品分类表
public class Category implements Serializable {

?private static final long serialVersionUID = 1L;
?
?private Integer id;
?private String name;
??? private String description;
???
??? public Category(){
??? ?
??? }

?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;
?}

?public String getDescription() {
??return description;
?}

?public void setDescription(String description) {
??this.description = description;
?}
???
???
}
Category.hbm.xml如下:

<?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="model.Category" table="category">
??<id name="id" type="java.lang.Integer">
?? <column name="ID" precision="8"></column>
?? <generator column="name" length="40" type="java.lang.String"></property>
??<property name="description" column="description" length="200" type="java.lang.String"></property>
??
?</class>
</hibernate-mapping>

然后是产品:

package model;

import java.io.Serializable;
//产品表
public class Product implements Serializable {

?private static final long serialVersionUID = 1L;
?
?private Integer id;
?private String name;
?private Double price;
?private String description;
?private Category category;
?
?public Product(){
??
?}

?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;
?}

?public Double getPrice() {
??return price;
?}

?public void setPrice(Double price) {
??this.price = price;
?}

?public String getDescription() {
??return description;
?}

?public void setDescription(String description) {
??this.description = description;
?}

?public Category getCategory() {
??return category;
?}

?public void setCategory(Category category) {
??this.category = category;
?}
?
?

}
然后是:Product.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="model.Product" table="product" >
??<id name="id" type="java.lang.Integer">
?? <column name="ID" precision="8"></column>
?? <generator column="name" length="200" type="java.lang.String"></property>
??<property name="price" column="price" precision="8" type="java.lang.Double"></property>
??<property name="description" column="description" length="2000" type="java.lang.String"></property>
??<!-- lazy="false" 表示我要立即加载 -->
??<many-to-one name="category" lazy="false">
??? <column name="CATEGORY_ID" precision="8" scale="0"></column>
??</many-to-one>
?</class>
</hibernate-mapping>

hibernate.cfg.xml的配置

<?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.url">jdbc:oracle:thin:@localhost:1521:ORCL</property>
??<property name="connection.username">scott</property>
??<property name="connection.password">123456</property>
??<property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
??<property name="dialect">org.hibernate.dialect.Oracle10gDialect</property>
??<property name="current_session_context_class">thread</property>
??<property name="show_sql">true</property>
??????? <property name="hbm2ddl.auto">update</property>
??????? <property name="format_sql">true</property>
??????? <!-- c3p0连接池的配置 -->
??????? <property name="connection_provider_class">
???????? org.hibernate.connection.C3P0ConnectionProvider
??????? </property>
??????? <property name="hibernate.c3p0.min_size">5</property>
??????? <property name="hibernate.c3p0.max_size">10</property>
??<property name="hibernate.c3p0.max_statements">50</property>
??<property name="hibernate.c3p0.timeout">3600</property>
??<property name="hibernate.c3p0.idle_test_period">120</property>
??<property name="hibernate.c3p0.acquire_increment">2</property>
??????? <mapping resource="model/Category.hbm.xml"/>?
??????? <mapping resource="model/Product.hbm.xml"/>??
?</session-factory>
</hibernate-configuration>

?