hibernate 缓存初试

最新推荐文章于 2021-10-06 12:05:17 发布

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#Hibernate #Cache #log4j #JDBC #XML

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本文介绍了一个使用Hibernate配置二级缓存的例子。通过配置hibernate.cfg.xml文件启用EhCache作为缓存提供者，并展示了如何在ComPermission.hbm.xml中为实体类ComPermission设置缓存策略。此外，还提供了测试代码及log4j配置，验证了缓存的有效性。

配置二级缓存

hibernate.cfg.xml

<?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="hibernate.cache.provider_class">org.hibernate.cache.EhCacheProvider</property>

  <property name="hibernate.dialect">org.hibernate.dialect.SQLServerDialect</property>
  <property name="hibernate.connection.driver_class">net.sourceforge.jtds.jdbc.Driver</property>
  <property name="hibernate.connection.url">jdbc:jtds:sqlserver://localHost:1433/DSO</property>
  <property name="hibernate.connection.username">sa</property>
  <property name="hibernate.connection.password">sa</property>
  <property name="show_sql">false</property>

  <mapping resource="ComPermission.hbm.xml" />
 </session-factory>
</hibernate-configuration>

ehcache.xml

<ehcache>
         <diskStore path="java.io.tmpdir" />
         <defaultCache
            maxElementsInMemory="10000"
            eternal="false"             
            timeToIdleSeconds="1200"     
            timeToLiveSeconds="1200"     
            overflowToDisk="true"       
         />
    </ehcache>

ComPermission.hbm.xml

<?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">
<hibernate-mapping>
 <class name="ComPermission" table="JB_COM_PERMISSION" dynamic-insert="true" dynamic-update="true">
  <cache usage="read-write" include="all" />
  <id name="permissionId" type="java.lang.String">
   <column name="PERMISSION_ID" length="5" />
   <generator class="assigned"></generator>
  </id>
  <property name="permissionCode" type="java.lang.String">
   <column name="PERMISSION_CODE" length="5" not-null="true" />
  </property>
  <property name="permissionName" type="java.lang.String">
   <column name="PERMISSION_NAME" length="30" not-null="true" />
  </property>
  <property name="remark" type="java.lang.String">
   <column name="REMARK" length="255" />
  </property>
 </class>
</hibernate-mapping>

Java实体类 ComPermission

public class ComPermission implements java.io.Serializable {

    // Fields

    private String permissionId;
    private String permissionCode;
    private String permissionName;
    private String remark;

}

log4j设置

log4j.category.org.hibernate.cache=DEBUG,CA
log4j.category.org.hibernate.SQL=DEBUG,CA

测试代码

public static void main(String[] args) {
	    System.out.println(HibernateSessionFactory.getConfiguration());   
        System.out.println("|||||||||||||||||||||||||||||||||||||||||||");   
        Session session = HibernateSessionFactory.getSessionFactory().openSession();   
        long start = System.currentTimeMillis();
        try {   
            ComPermission permission = (ComPermission) session.load(ComPermission.class, "10001");   
            System.out.println(permission.getPermissionName());   
        } catch (RuntimeException re) {   
            throw re;   
        } finally {   
            session.close();   
        }   
        System.out.println("time :" + (System.currentTimeMillis() - start));   
        System.out.println("-----------------------------------------------");   
  
        Transaction tran = null;   
        Session session2 = HibernateSessionFactory.getSessionFactory().openSession();   
        start = System.currentTimeMillis();
        try {   
            tran = session2.beginTransaction();   
            ComPermission permission = (ComPermission) session2.load(ComPermission.class, "10001");   
            permission.setPermissionName(permission.getPermissionName() + "!");   
            System.out.println(permission.getPermissionName());   
            session2.update(permission);   
            tran.commit();   
        } catch (RuntimeException re) {   
            tran.rollback();   
            throw re;   
        } finally {   
            session2.close();   
        }   
        System.out.println("time :" + (System.currentTimeMillis() - start));   
        System.out.println("---------------------------------------------------------");   
  
        
        Session session3 = HibernateSessionFactory.getSessionFactory().openSession();   
        start = System.currentTimeMillis();   
        try {   
            ComPermission permission = (ComPermission) session3.load(ComPermission.class, "10001");   
            System.out.println(permission.getPermissionName());   
        } catch (RuntimeException re) {   
            throw re;   
        } finally {   
            session3.close();   
        }   
        System.out.println("time :" + (System.currentTimeMillis() - start));   
        System.out.println("---------------------------------------------------------");   
  
        
        Session session4 = HibernateSessionFactory.getSessionFactory().openSession();   
        start = System.currentTimeMillis();   
        try {   
            ComPermission permission = (ComPermission) session4.load(ComPermission.class, "10001");   
            System.out.println(permission.getPermissionName());   
        } catch (RuntimeException re) {   
            throw re;   
        } finally {   
            session4.close();   
        }   
        System.out.println("time :" + (System.currentTimeMillis() - start));   
    }

log信息

DEBUG  [org.hibernate.cache.CacheFactory.createCache:39]  instantiating cache region: ComPermission usage strategy: read-write
WARN  [org.hibernate.cache.EhCacheProvider.buildCache:103]  Could not find configuration [ComPermission]; using defaults.
DEBUG  [org.hibernate.cache.EhCacheProvider.buildCache:106]  started EHCache region: ComPermission
org.hibernate.cfg.Configuration@c4fe76
|||||||||||||||||||||||||||||||||||||||||||
DEBUG  [org.hibernate.cache.ReadWriteCache.get:75]  Cache lookup: ComPermission#10001  //尝试在缓存中查找对象  ComPermission#10001  
DEBUG  [org.hibernate.cache.EhCache.get:104]  key: ComPermission#10001
DEBUG  [org.hibernate.cache.EhCache.get:113]  Element for ComPermission#10001 is null
DEBUG  [org.hibernate.cache.ReadWriteCache.get:91]  Cache miss: ComPermission#10001    //找不到
DEBUG  [org.hibernate.jdbc.AbstractBatcher.log:346]  select compermiss0_.PERMISSION_ID as PERMISSION1_0_0_, compermiss0_.PERMISSION_CODE as PERMISSION2_0_0_, compermiss0_.PERMISSION_NAME as PERMISSION3_0_0_, compermiss0_.REMARK as REMARK0_0_ from JB_COM_PERMISSION compermiss0_ where compermiss0_.PERMISSION_ID=?
DEBUG  [org.hibernate.cache.ReadWriteCache.put:148]  Caching: ComPermission#10001
DEBUG  [org.hibernate.cache.EhCache.get:104]  key: ComPermission#10001
DEBUG  [org.hibernate.cache.EhCache.get:113]  Element for ComPermission#10001 is null
DEBUG  [org.hibernate.cache.ReadWriteCache.put:160]  Cached: ComPermission#10001      //将查询到的缓存起来
测试信息
time :47
-----------------------------------------------
DEBUG  [org.hibernate.cache.ReadWriteCache.get:75]  Cache lookup: ComPermission#10001
DEBUG  [org.hibernate.cache.EhCache.get:104]  key: ComPermission#10001
DEBUG  [org.hibernate.cache.ReadWriteCache.get:85]  Cache hit: ComPermission#10001     //找到了
测试信息!
DEBUG  [org.hibernate.cache.ReadWriteCache.lock:113]  Invalidating: ComPermission#10001
DEBUG  [org.hibernate.cache.EhCache.get:104]  key: ComPermission#10001
DEBUG  [org.hibernate.jdbc.AbstractBatcher.log:346]  update JB_COM_PERMISSION set PERMISSION_NAME=? where PERMISSION_ID=?
DEBUG  [org.hibernate.cache.ReadWriteCache.release:195]  Releasing: ComPermission#10001  //由于对象被更新 将缓存中的对象释放
DEBUG  [org.hibernate.cache.EhCache.get:104]  key: ComPermission#10001
time :31
---------------------------------------------------------
DEBUG  [org.hibernate.cache.ReadWriteCache.get:75]  Cache lookup: ComPermission#10001
DEBUG  [org.hibernate.cache.EhCache.get:104]  key: ComPermission#10001
DEBUG  [org.hibernate.cache.ReadWriteCache.get:94]  Cached item was locked: ComPermission#10001  //lockable.isGettable(txTimestamp)==false
DEBUG  [org.hibernate.jdbc.AbstractBatcher.log:346]  select compermiss0_.PERMISSION_ID as PERMISSION1_0_0_, compermiss0_.PERMISSION_CODE as PERMISSION2_0_0_, compermiss0_.PERMISSION_NAME as PERMISSION3_0_0_, compermiss0_.REMARK as REMARK0_0_ from JB_COM_PERMISSION compermiss0_ where compermiss0_.PERMISSION_ID=?
DEBUG  [org.hibernate.cache.ReadWriteCache.put:148]  Caching: ComPermission#10001
DEBUG  [org.hibernate.cache.EhCache.get:104]  key: ComPermission#10001
DEBUG  [org.hibernate.cache.ReadWriteCache.put:160]  Cached: ComPermission#10001   //重新缓存对象
测试信息!
time :0
---------------------------------------------------------
DEBUG  [org.hibernate.cache.ReadWriteCache.get:75]  Cache lookup: ComPermission#10001
DEBUG  [org.hibernate.cache.EhCache.get:104]  key: ComPermission#10001
DEBUG  [org.hibernate.cache.ReadWriteCache.get:85]  Cache hit: ComPermission#10001     //缓存命中
测试信息!
time :0