Hibernate-------一级缓存/二级缓存/查询缓存

例子:

model:

 

@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;
	}
	
	

}

 

 

测试:

 

package com.hibernate.test;

import java.util.Date;
import java.util.Iterator;
import java.util.List;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.annotations.Cache;
import org.hibernate.annotations.CacheConcurrencyStrategy;
import org.hibernate.cfg.AnnotationConfiguration;
import org.hibernate.tool.hbm2ddl.SchemaExport;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;

import com.hibernate.model.Category;
import com.hibernate.model.Topic;

public class HQLTest {

	private static SessionFactory sf = null;

	@BeforeClass
	public static void beforeClass() {
		// new SchemaExport(new
		// AnnotationConfiguration().configure()).create(false, true);
		sf = new AnnotationConfiguration().configure().buildSessionFactory();
	}

	@AfterClass
	public static void afterClass() {
		sf.close();
	}

	@Test
	public void testSchemaExport() {
		new SchemaExport(new AnnotationConfiguration().configure()).create(
				false, true);
		
		
	}

	public static void main(String[] args) {
//		new HQLTest().testSchemaExport();
		HQLTest t =	new HQLTest();
		t.beforeClass();
		t.testCache2();
		
	}
	
	
	@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();
	}
	
	
	
	//一级缓存
	//只会发出一条查询语句
	@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();
		
	}
	
	
	
	/**
	 * 二级缓存
	 * 默认情况会发两条查询语句
	 * 
	 * 设置二级缓存,加入包ehcache-1.2.3.jar,在发行包中(还有另外几种二级缓存的实现厂家)
	 * 
	 * 加入配置文件ehcache.xml,加入commons-logging-1.1.1.jar包
	 * 
	 * 更改hibernate.hbm.xml文件
	 * <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>
	 *
	 *在Category类中加入注解, 	@Cache(usage=CacheConcurrencyStrategy.READ_WRITE)
	 *
	 *可以了，现在利用了二级缓存，只发出一条查询语句
	 */
	
	@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();
	}
	
	
	/**
	 * 查询缓存,查询条件一样 
	 * 设置.setCacheable(true)
	 */
	
	@Test
	public void testQueryCache3() {
		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();
	}
		
	
}

 

 

 

 

 

 缓存策略提供商（Cache Providers）

Cache Provider class Type Cluster Safe Query Cache Supported

Hashtable (not intended for production use)	org.hibernate.cache.HashtableCacheProvider	memory		yes
EHCache	org.hibernate.cache.EhCacheProvider	memory, disk		yes
OSCache	org.hibernate.cache.OSCacheProvider	memory, disk		yes
SwarmCache	org.hibernate.cache.SwarmCacheProvider	clustered (ip multicast)	yes (clustered invalidation)
JBoss Cache 1.x	org.hibernate.cache.TreeCacheProvider	clustered (ip multicast), transactional	yes (replication)	yes (clock sync req.)
JBoss Cache 2	org.hibernate.cache.jbc2.JBossCacheRegionFactory	clustered (ip multicast), transactional	yes (replication or invalidation)	yes (clock sync req.)