01-08-02【Nhibernate (版本3.3.1.4000) 出入江湖】二级缓存：NHibernate自带的HashtableProvider

第一步骤：hibernate.cfg.xml文件补上如下配置：

<?xml version="1.0" encoding="utf-8"?>
<!-- 
This template was written to work with NHibernate.Test.
Copy the template to your NHibernate.Test project folder and rename it in hibernate.cfg.xml and change it 
for your own use before compile tests in VisualStudio.
-->
<!-- This is the System.Data.dll provider for SQL Server -->
<hibernate-configuration  xmlns="urn:nhibernate-configuration-2.2" >
    <session-factory name="NHibernate.Test123456">
        <property name="connection.driver_class">NHibernate.Driver.SqlClientDriver</property>
        <property name="connection.connection_string">

      <!--用于测试自动生成数据库表（不自动生成数据库）-->
      <!--<property name="hbm2ddl.auto">update</property>-->
      Server=(local);initial catalog=NHibernateSampleAutoCreateTable;Integrated Security=SSPI

      <!--Server=(local);initial catalog=NHibernateSample;Integrated Security=SSPI-->
    </property>
        <property name="dialect">NHibernate.Dialect.MsSql2008Dialect</property>

    <!--输出所有的SQL语句到控制台，一般开发打开这个-->
    <property name="show_sql">true</property>
    <!--整齐的SQL输出到控制台-->
    <property name="format_sql">true</property>
    <!--自动生成数据库表（不自动生成数据库）-->
    <property name="hbm2ddl.auto">update</property>
    <!--在数据表设计中如果采用了 bit 类型的字段，并且对应了业务类中类型为 bool 值，一定要如上设置下-->
    <property name="query.substitutions">true 1, false 0, yes 'Y', no 'N'</property>
    
     <!--=======加入Nhibernate自身的HashtabeCache的二级缓存配置=============================-->
    <!--1.配置二级缓存提供程序-->
    <property name="cache.provider_class">NHibernate.Cache.HashtableCacheProvider</property>
    <!--2.显式启用二级缓存-->
    <property name ="cache.use_second_level_cache">true</property>
    <!--4.启动查询缓存-->
    <property name="cache.use_query_cache">true</property>

    <!--实体类所在的程序集-->
    <mapping assembly="Model"/>
     <!--3.配置映射的二级缓存-->
    <class-cache class="Model.Customer,Model" usage="read-write"/>
    <!--<collection-cache collection ="集合名称" region="默认集合名称"
                      usage="read-write"/>-->

    </session-factory>
</hibernate-configuration>

实体类上也可以配二级缓存策略,如：

Customer.hbm.xml

<?xml version="1.0" encoding="utf-8" ?>
<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" 
                   namespace="Model" 
                   assembly="Model" 
                    default-lazy="true">
  
  <class name="Model.Customer, Model"
         table="Customer"
         discriminator-value="0" lazy="false">
    <!--1.这个不是必须的，因为在nhibernate.cfg.xml文件中已经有了一个总配置
        2.cache标签必须在id标签前面
    -->
    <cache usage="read-write"/>
    <!--unsaved-value="0" 主键表中不需要定义，而是需要在子表中定义-->
    <id name="CustomerId"
        column="CustomerId"
        type="int" 
        unsaved-value="0">
      <generator class="native" />
      <!-- unsaved-value used to be null and generator was increment in h2.0.3 -->
    </id>
。。。。。。。。。。。。。。。
    <set name="Orders" table="Order"  lazy="true"
         generic="true"
          inverse="false" cascade="all">
      <!--二级缓存策略-->
      <cache usage="read-write"/>
      <key column="CustomerId" foreign-key="FK_CustomerOrders"/> 
      <one-to-many class="Model.Order,Model"/>
    </set>
  </class>
</hibernate-mapping>

测试1：

二级缓存与Get方法+Lazy设置的关系：

测试图解：

经测试，得出如下结论：

Get方法+Lazy配置+二级缓存测试结果：

Customer.hbm.xml的<Set name="Orders" Customer.hbm.xml的<Set name="Orders"

lazy="true"> 　　　　　　　　　　　　　　 lazy="false">

Customer数据库中Order个数等于零 Get方法从二级缓存获取Customer Get方法从二级缓存获取Customer

Customer数据库中Order个数大于零 Get方法从二级缓存获取Customer Get方法从不从二级缓存获取Customer

------------------------更新二级缓存测试---------------------------------------------------------------

测试更新-1：

前置条件：

1.Customer没Orders

  <class name="Model.Customer, Model"
         table="Customer"
         discriminator-value="0" lazy="true">
    <!--1.这个不是必须的，因为在nhibernate.cfg.xml文件中已经有了一个总配置
        2.cache标签必须在id标签前面
    -->
    <cache usage="read-write"/>

测试代码：

        [TestMethod]
        public void TestSessionFactoryCacheUpdateCustomerHavingNotOrders()
        {
            CustomerService customerService = new CustomerService();

            Customer customer = new Customer()
            {
                FirstName = "Test",
                LastName = "TestSessionFactoryCache",
                Age = 10
            };

            customerService.Add(customer);
            int customerId = customer.CustomerId;


            Console.WriteLine("第1次获取数据并且更新------------------------------：");
            Customer customerGet1 = customerService.Get(customerId);

            Console.WriteLine("更新前：Id:{0}-->FirtstName:{1}"
                , customerGet1.CustomerId, customerGet1.FirstName);

            customerGet1.FirstName = "我是更新后的FirstName"; //修改FirstName
            customerService.Update(customerGet1);  //保存更新得到数据库。

            Console.WriteLine("更新后：Id:{0}-->FirtstName:{1}"
                , customerGet1.CustomerId, customerGet1.FirstName);

            Console.WriteLine("第2次获取数据==============================：");
            Customer customerGet2 = customerService.Get(customerId);
            Console.WriteLine("Id:{0}-->FirtstName:{1}"
                , customerGet2.CustomerId, customerGet2.FirstName);

            Console.WriteLine("第3次获取数据==============================：");
            Customer customerGet3 = customerService.Get(customerId);
            Console.WriteLine("Id:{0}-->FirtstName:{1}"
                , customerGet3.CustomerId, customerGet3.FirstName);

        }

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