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

原文地址:https://www.cnblogs.com/hongten/p/2108883.html