Hibernate二级缓存存集合对象
新建java project项目：chapter17_setehcache
hibernate.cfg.xml
代码：
<?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">
<!-- Generated by MyEclipse Hibernate Tools. --> <hibernate-configuration>
<session-factory> <property name="dialect"> org.hibernate.dialect.MySQLDialect </property> <property name="connection.url"> jdbc:mysql://localhost:3307/users </property> <property name="connection.username">root</property> <property name="connection.password">root</property> <property name="connection.driver_class"> com.mysql.jdbc.Driver </property> <property name="myeclipse.connection.profile"> mysqlusers </property> <property name="show_sql">true</property> <property name="format_sql">true</property> <property name="current_session_context_class">thread</property> <property name="cache.provider_class"> org.hibernate.cache.EhCacheProvider </property> <mapping resource="com/b510/examplex/Category.hbm.xml" /> <mapping resource="com/b510/examplex/Product.hbm.xml" />
</session-factory>
</hibernate-configuration>
ehcache.xml
代码：
<?xml version="1.0" encoding="UTF-8"?> <ehcache> <!-- 说明：maxElementsInMemory 设置 保存在内存中的缓存对象的最大数量 etemal 设置缓存中对象 是否永远不过期，如果值为true，超过设置被忽略，缓存对象永远不过期 timeToIdleSeconds 设置缓存中对象在他过期之前的最大空闲时间，单位为秒 timeToLiveSeconds 设置缓存中对象在他过期之前的最大生存时间 ，单位为秒 overflowToDisk 设置内存中的缓存对象达到maxElementsInMemory限制时，是否将缓存对象保存到硬盘中 --> <!-- --> <diskStore path="java.io.tmpdir"/> <defaultCache maxElementsInMemory="10000" eternal="false" timeToIdleSeconds="120" timeToLiveSeconds="120" overflowToDisk="true"/> <cache name="com.b510.examples.Product" maxElementsInMemory="1000" eternal="true" timeToIdleSeconds="300" timeToLiveSeconds="600" overflowToDisk="true"/> <cache name="com.b510.example.Category.products" maxElementsInMemory="1000" eternal="true" timeToIdleSeconds="300" timeToLiveSeconds="600" overflowToDisk="true"/> <cache name="com.b510.example.Category" maxElementsInMemory="1000" eternal="true" timeToIdleSeconds="300" timeToLiveSeconds="600" overflowToDisk="true"/> </ehcache>
Category.java
代码：
package com.b510.examplex;
import java.util.HashSet; import java.util.Set;
/** * Category entity. @author MyEclipse Persistence Tools */
public class Category implements java.io.Serializable {
private static final long serialVersionUID = 7187702390542761264L; private Integer id; private String name; private String description; private Set products = new HashSet(0);
public Category() { }
public Integer getId() { return this.id; }
public void setId(Integer id) { this.id = id; }
public String getName() { return this.name; }
public void setName(String name) { this.name = name; }
public String getDescription() { return this.description; }
public void setDescription(String description) { this.description = description; }
public Set getProducts() { return this.products; }
public void setProducts(Set products) { this.products = products; }
}
Product.java
代码；
package com.b510.examplex;
/** * Product entity. @author MyEclipse Persistence Tools */
public class Product implements java.io.Serializable {
private static final long serialVersionUID = 1449100306422352085L; private Integer id; private Category category; private String name; private String price; private String descripton;
public Product() { }
public Integer getId() { return this.id; }
public void setId(Integer id) { this.id = id; }
public Category getCategory() { return this.category; }
public void setCategory(Category category) { this.category = category; }
public String getName() { return this.name; }
public void setName(String name) { this.name = name; }
public String getPrice() { return this.price; }
public void setPrice(String price) { this.price = price; }
public String getDescripton() { return this.descripton; }
public void setDescripton(String descripton) { this.descripton = descripton; }
}
Category.hbm.xml
代码：
<?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"> <!-- Mapping file autogenerated by MyEclipse Persistence Tools --> <hibernate-mapping> <class name="com.b510.examplex.Category" table="category" catalog="users"> <cache usage="read-only"/> <id name="id" type="java.lang.Integer"> <column name="id" /> <generator class="increment"></generator> </id> <property name="name" type="java.lang.String"> <column name="name" length="500" /> </property> <property name="description" type="java.lang.String"> <column name="description" length="500" /> </property> <set name="products" inverse="true"> <cache usage="read-only"/> <key> <column name="category_id" /> </key> <one-to-many class="com.b510.examplex.Product" /> </set> </class> </hibernate-mapping>
Product.hbm.xml
代码：
<?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"> <!-- Mapping file autogenerated by MyEclipse Persistence Tools --> <hibernate-mapping> <class name="com.b510.examplex.Product" table="product" catalog="users"> <id name="id" type="java.lang.Integer"> <column name="id" /> <generator class="increment"></generator> </id> <many-to-one name="category" class="com.b510.examplex.Category" fetch="select"> <column name="category_id" /> </many-to-one> <property name="name" type="java.lang.String"> <column name="name" length="500" /> </property> <property name="price" type="java.lang.String"> <column name="price" length="10" /> </property> <property name="descripton" type="java.lang.String"> <column name="descripton" length="500" /> </property> </class> </hibernate-mapping>
测试代码：
HibernateTest.java
代码：
/** * */ package com.b510.examplex;
import java.util.Set;
import org.hibernate.Session;
/** * * @author XHW * * @date 2011-7-17 * */ public class HibernateTest { public static void main(String[] args) { new HibernateTest().test(); } public void test(){ Session session=HibernateSessionFactoryUtil.getSessionFactory().openSession(); session.beginTransaction(); Category c1=(Category)session.get(Category.class, 1); System.out.println("id:"+c1.getId()+" name: "+c1.getName()); Set<Product> products=c1.getProducts(); for(Product p:products){ System.out.println(p.getName()); } session.getTransaction().commit(); System.out.println("--------------------------------"); Session session2=HibernateSessionFactoryUtil.getSessionFactory().openSession(); session2.beginTransaction(); Category c2=(Category)session2.get(Category.class, 1); Set<Product> products2=c1.getProducts(); for(Product p2:products2){ System.out.println(p2.getName()); } session2.getTransaction().commit(); } }
运行效果：
log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment). log4j:WARN Please initialize the log4j system properly. Hibernate: select category0_.id as id0_0_, category0_.name as name0_0_, category0_.description as descript3_0_0_ from users.category category0_ where category0_.id=? id:1 name: java Hibernate: select products0_.category_id as category2_1_, products0_.id as id1_, products0_.id as id1_0_, products0_.category_id as category2_1_0_, products0_.name as name1_0_, products0_.price as price1_0_, products0_.descripton as descripton1_0_ from users.product products0_ where products0_.category_id=? java WEB开发与实战 java SE应用程序设计 -------------------------------- java WEB开发与实战 java SE应用程序设计