hibernate.cfg.xm 中加入 <property name="cache.use_second_level_cache">true</property> <property name="cache.provider_class">org.hibernate.cache.EhCacheProvider</property>
<?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.driver_class">com.mysql.jdbc.Driver</property> <property name="connection.url">jdbc:mysql://localhost/hibernate</property> <property name="connection.username">root</property> <property name="connection.password">bjsxt</property> <property name="dialect">org.hibernate.dialect.MySQLDialect</property> <!-- <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property> <property name="connection.url">jdbc:oracle:thin:@localhost:1521:SXT</property> <property name="connection.username">scott</property> <property name="connection.password">tiger</property> <property name="dialect">org.hibernate.dialect.OracleDialect</property> --> <!-- JDBC connection pool (use the built-in) --> <property name="connection.pool_size">1</property> <!-- Enable Hibernate's automatic session context management --> <property name="current_session_context_class">thread</property> <!-- Disable the second-level cache <property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property> --> <property name="cache.use_second_level_cache">true</property> <property name="cache.provider_class">org.hibernate.cache.EhCacheProvider</property> <property name="cache.use_query_cache">true</property> <!-- Echo all executed SQL to stdout --> <property name="show_sql">true</property> <property name="format_sql">true</property> <!-- Drop and re-create the database schema on startup <property name="hbm2ddl.auto">update</property> --> <!-- <mapping resource="com/bjsxt/hibernate/Group.hbm.xml"/> <mapping resource="com/bjsxt/hibernate/User.hbm.xml"/> --> <mapping class="com.bjsxt.hibernate.Category"/> <mapping class="com.bjsxt.hibernate.Msg"/> <mapping class="com.bjsxt.hibernate.Topic"/> </session-factory> </hibernate-configuration> l
ehcache.xml
<ehcache> <!-- Sets the path to the directory where cache .data files are created. If the path is a Java System Property it is replaced by its value in the running VM. The following properties are translated: user.home - User's home directory user.dir - User's current working directory java.io.tmpdir - Default temp file path --> <diskStore path="java.io.tmpdir"/> <!--Default Cache configuration. These will applied to caches programmatically created through the CacheManager. The following attributes are required for defaultCache: maxInMemory - Sets the maximum number of objects that will be created in memory eternal - Sets whether elements are eternal. If eternal, timeouts are ignored and the element is never expired. timeToIdleSeconds - Sets the time to idle for an element before it expires. Is only used if the element is not eternal. Idle time is now - last accessed time timeToLiveSeconds - Sets the time to live for an element before it expires. Is only used if the element is not eternal. TTL is now - creation time overflowToDisk - Sets whether elements can overflow to disk when the in-memory cache has reached the maxInMemory limit. --> <defaultCache maxElementsInMemory="10000" eternal="false" timeToIdleSeconds="120" timeToLiveSeconds="1200" overflowToDisk="true" /> <!--Predefined caches. Add your cache configuration settings here. If you do not have a configuration for your cache a WARNING will be issued when the CacheManager starts The following attributes are required for defaultCache: name - Sets the name of the cache. This is used to identify the cache. It must be unique. maxInMemory - Sets the maximum number of objects that will be created in memory eternal - Sets whether elements are eternal. If eternal, timeouts are ignored and the element is never expired. timeToIdleSeconds - Sets the time to idle for an element before it expires. Is only used if the element is not eternal. Idle time is now - last accessed time timeToLiveSeconds - Sets the time to live for an element before it expires. Is only used if the element is not eternal. TTL is now - creation time overflowToDisk - Sets whether elements can overflow to disk when the in-memory cache has reached the maxInMemory limit. --> <!-- Sample cache named sampleCache1 This cache contains a maximum in memory of 10000 elements, and will expire an element if it is idle for more than 5 minutes and lives for more than 10 minutes. If there are more than 10000 elements it will overflow to the disk cache, which in this configuration will go to wherever java.io.tmp is defined on your system. On a standard Linux system this will be /tmp" --> <cache name="sampleCache1" maxElementsInMemory="10000" eternal="false" timeToIdleSeconds="300" timeToLiveSeconds="600" overflowToDisk="true" /> <!-- Sample cache named sampleCache2 This cache contains 1000 elements. Elements will always be held in memory. They are not expired. --> <cache name="sampleCache2" maxElementsInMemory="1000" eternal="true" timeToIdleSeconds="0" timeToLiveSeconds="0" overflowToDisk="false" /> --> <!-- Place configuration for your caches following --> </ehcache>
把那个类放入二级缓存中，用注解
Category.java
package com.bjsxt.hibernate; import javax.persistence.Entity; import javax.persistence.GeneratedValue; import javax.persistence.Id; import org.hibernate.annotations.Cache; import org.hibernate.annotations.CacheConcurrencyStrategy; @Entity //@BatchSize(size=5) @Cache(usage = CacheConcurrencyStrategy.READ_WRITE) public class Category { private int id; private String name; @Id @GeneratedValue public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } }
查询缓存依赖于二级缓存
缓存测试
HibernateCacheTest.java
package com.bjsxt.hibernate; import java.util.Date; import java.util.Iterator; import java.util.List; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.AnnotationConfiguration; import org.hibernate.tool.hbm2ddl.SchemaExport; import org.junit.AfterClass; import org.junit.BeforeClass; import org.junit.Test; public class HibernateCacheTest { private static SessionFactory sf; @BeforeClass public static void beforeClass() { sf = new AnnotationConfiguration().configure().buildSessionFactory(); } @AfterClass public static void afterClass() { sf.close(); } @Test public void testSchemaExport() { new SchemaExport(new AnnotationConfiguration().configure()).create(false, true); } @Test public void testSave() { Session session = sf.openSession(); session.beginTransaction(); for(int i=0; i<10; i++) { Category c = new Category(); c.setName("c" + i); Topic t = new Topic(); t.setCategory(c); t.setTitle("t" + i); t.setCreateDate(new Date()); session.save(c); session.save(t); } session.getTransaction().commit(); session.close(); } //join fetch @Test public void testCache1() { Session session = sf.openSession(); session.beginTransaction(); Category c = (Category)session.load(Category.class, 1); System.out.println(c.getName()); Category c2 = (Category)session.load(Category.class, 1); System.out.println(c2.getName()); session.getTransaction().commit(); session.close(); } //join fetch @Test public void testCache2() { Session session = sf.openSession(); session.beginTransaction(); Category c = (Category)session.load(Category.class, 1); System.out.println(c.getName()); session.getTransaction().commit(); session.close(); Session session2 = sf.openSession(); session2.beginTransaction(); Category c2 = (Category)session2.load(Category.class, 1); System.out.println(c2.getName()); session2.getTransaction().commit(); session2.close(); } //join fetch @Test public void testQueryCache() { Session session = sf.openSession(); session.beginTransaction(); List<Category> categories = (List<Category>)session.createQuery("from Category") .setCacheable(true).list(); session.getTransaction().commit(); session.close(); Session session2 = sf.openSession(); session2.beginTransaction(); List<Category> categories2 = (List<Category>)session2.createQuery("from Category") .setCacheable(true).list(); session2.getTransaction().commit(); session2.close(); } public static void main(String[] args) { beforeClass(); } }
