hibernate2级缓存配置与测试

新建test项目→新建实体类Person→加入jar包
Person实体类代码：

@Entity
@Table(name = "person")
@Cache(usage = CacheConcurrencyStrategy.READ_WRITE)
public class Person implements java.io.Serializable {

	private static final long serialVersionUID = 1L;

	private Integer id;
	private String name;
	private String age;
...略去get/set
}

Person.hbm.xml代码：

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
	"-//Hibernate/Hibernate Mapping DTD 2.0//EN"
	"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping package="com.test.cache">

	<class name="Person" table="person">
		<cache usage="read-write" />
		<id name="id" type="int">
			<generator class="increment" />
		</id>
		<property name="name" column="name" type="string"
			not-null="false" length="36" />

		<property name="age" column="age" type="string"
			length="100" />

	</class>
</hibernate-mapping>

操作步骤如下：：：
第一步：加入到类路径下hibernate.cfg.xml

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration  
    PUBLIC "-//Hibernate/Hibernate Configuration DTD//EN"  
    "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">  
<hibernate-configuration>  
    <session-factory>  
        <property name="connection.driver_class">  
            org.gjt.mm.mysql.Driver  
        </property>  
        <property name="connection.url">  
            jdbc:mysql://192.168.1.120:3306/test?useUnicode=true&amp;characterEncoding=utf-8  
        </property>  
        <property name="connection.username">root</property>  
        <property name="connection.password">123456</property>  
  
        <property name="dialect">  
            org.hibernate.dialect.MySQLDialect  
        </property>
        <property name="connection.pool_size">10</property>  
        <property name="hibernate.jdbc.batch_size">10</property>  
  
        <property name="show_sql">true</property>  
        <property name="format_sql">true</property>  
        <property name="current_session_context_class">thread</property>  
        <property name="hbm2ddl.auto">none</property>  
              <property name="hibernate.cache.provider_class">  
           org.hibernate.cache.EhCacheProvider  
       </property>  
         
       <!-- Enable Second-Level Cache and Query Cache Settings -->  
       <property name="hibernate.cache.use_second_level_cache">  
           true  
       </property>  
       <property name="hibernate.cache.use_query_cache">  
           false  
       </property>  
 
       <!-- 注解配置  -->  
       <mapping class="com.test.cache.Person" />
       
       <!-- 映射文件 -->  
        <mapping  
            resource="com/test/cache/Person.hbm.xml" />  
    </session-factory>  
</hibernate-configuration>

第二步：测试一级缓存与二级缓存/查询缓存
1.测试一级缓存代码（get()方法/load()方法+second_level_cache=false,query_cache=false）：

/**
	 * @param args
	 */
	@SuppressWarnings("unchecked")
	public static void main(String[] args) {
		SessionFactory sessionFactory = null;
		try {
			System.out.println("ehcache - hibernate Test ...");
			Configuration config = new AnnotationConfiguration()
					.configure("hibernate.cfg.xml");
			sessionFactory = config.buildSessionFactory();

			System.out.println("在同一个session中执行：：：");
			Session session = sessionFactory.getCurrentSession();
			Transaction ta = session.beginTransaction();
			Person person = (Person) session.get(Person.class, 1);
			System.out.println(person.getName());

			System.out.println("第二次查询开始。。。。。");
			Person pern = (Person) session.get(Person.class, 1);
			ta.commit();
			System.out.println(pern.getName());
}

执行结果为：
ehcache - hibernate Test ...
log4j:WARN No appenders could be found for logger (org.hibernate.cfg.annotations.Version).
log4j:WARN Please initialize the log4j system properly.
在同一个session中执行：：：
Hibernate:
    select
        person0_.id as id0_0_,
        person0_.name as name0_0_,
        person0_.age as age0_0_
    from
        person person0_
    where
        person0_.id=?
yf
第二次查询开始。。。。。
yf
sessionFactory  closed.
可以看出第二次执行未执行sql
2.测试2级级缓存代码（get()方法/load方法+second_level_cache=true,query_cache=false）：

/**
	 * @param args
	 */
	@SuppressWarnings("unchecked")
	public static void main(String[] args) {
		SessionFactory sessionFactory = null;
		try {
			System.out.println("ehcache - hibernate Test ...");
			Configuration config = new AnnotationConfiguration()
					.configure("hibernate.cfg.xml");
			sessionFactory = config.buildSessionFactory();

			System.out.println("不在同一个session中执行======");
			Session session = sessionFactory.openSession();
			Transaction ta = session.beginTransaction();
			Person person = (Person) session.get(Person.class, 1);
			ta.commit();
			System.out.println(person.getName());

			System.out.println("第二次查询开始。。。。。");
			Session sess = sessionFactory.openSession();
			Transaction trans = session.beginTransaction();
			Person pern = (Person) sess.get(Person.class, 1);
			trans.commit();
			System.out.println(pern.getName());
}

执行结果为：
ehcache - hibernate Test ...
log4j:WARN No appenders could be found for logger (org.hibernate.cfg.annotations.Version).
log4j:WARN Please initialize the log4j system properly.
不在同一个session中执行======
Hibernate:
    select
        person0_.id as id0_0_,
        person0_.name as name0_0_,
        person0_.age as age0_0_
    from
        person person0_
    where
        person0_.id=?
yf
第二次查询开始。。。。。
yf
sessionFactory  closed.
可以看出第二次执行未执行sql
3.测试2级查询缓存（list()方法）+second_level=true,query_cache=false）：
这种方式，query查询会缓存查询结果数据到2级缓存里，但是不会执行查询缓存
4.测试2级查询缓存（list()方法）+second_level=true,query_cache=true）：

System.out.println("不在同一个session中执行list()======");
			Session session = sessionFactory.openSession();
			Transaction ta = session.beginTransaction();
			String hql = "select t from Person t where t.name='ryan'";
			Query que = session.createQuery(hql);
			que.setCacheable(true);
			System.out.println("list().size==" + que.list().size());
			ta.commit();

			System.out.println("第二次查询开始。。。。。");
			Session sess = sessionFactory.openSession();
			Transaction trans = session.beginTransaction();
			String shql = "select t from Person t where t.name='ryan'";
			Query query = sess.createQuery(shql);
			query.setCacheable(true);
			System.out.println("list().size==" + query.list().size());
			trans.commit();
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			if (null != sessionFactory) {
				sessionFactory.close();
			}
		}
		System.out.println("sessionFactory  closed.");
	}

执行结果：第二次查询并没有访问数据库，查询缓存使用hibernate生成的sql和参数生成缓存的key,再执行相同sql和相同条件的时候直接从缓存中去。
INFO org.hibernate.cache.UpdateTimestampsCache - starting update timestamps cache at region: org.hibernate.cache.UpdateTimestampsCache
INFO org.hibernate.cache.StandardQueryCache - starting query cache at region: org.hibernate.cache.StandardQueryCache
不在同一个session中执行list()======
Hibernate:
    select
        person0_.id as id0_,
        person0_.name as name0_,
        person0_.age as age0_
    from
        person person0_
    where
        person0_.name='ryan'
list().size==2
第二次查询开始。。。。。
list().size==2
INFO org.hibernate.impl.SessionFactoryImpl - closing
INFO org.hibernate.connection.DriverManagerConnectionProvider - cleaning up connection pool: jdbc:mysql://192.168.1.120:3306/test?useUnicode=true&characterEncoding=utf-8
sessionFactory  closed.