关于缓存：
缓存是介于物理数据源与应用程序之间，是对数据库中的数据复制一份临时放在内存中的容器，
其作用是为了减少应用程序对物理数据源访问的次数，从而提高了应用程序的运行性能。
Hibernate在进行读取数据的时候，根据缓存机制在相应的缓存中查询，如果在缓存中找到了需要的数据(我们把这称做“缓存命 中")，
则就直接把命中的数据作为结果加以利用，避免了大量发送SQL语句到数据库查询的性能损耗。
一般我们在项目整合中 存在数据访问的性能问题，研究了下缓存在各个阶段的应用，以在5个方面进行缓存的设计：
1.最底层可以配置的是MySQL自带的query cache，
2.mybatis的一级缓存，默认情况下都处于开启状态，只能使用自带的PerpetualCache，无法配置第三方缓存
3.mybatis的二级缓存，可以配置开关状态，默认使用自带的PerpetualCache，但功能比较弱，能够配置第三方缓存，
4.service层的缓存配置，结合spring，可以灵活进行选择
5.hibernate的一级缓存，默认也是开启状态，session级别的，可以自由使用。但这里注意下hibernate获取session的 方式。
6.hibernate的二级缓存需要引用 第三方的 插件，并在hibernate配置文件中进行相应的配置。
7.针对实际业务情况，直接缓存部分html页面，直接返回给客户端。
发现在整合的项目测试中被spring整合的mybatis和hibernate的一级缓存都失效了。
首先1.mybatis和hibernate的一级缓存生效的范围是sqlsession，是为了在sqlsession没有关闭时，业务需要重复查询相同数据使用的。一旦sqlsession关闭，则由这个sqlsession缓存的数据将会被清空。
spring管理的mybatis
@Test public void TestBi(){ ApplicationContext context = new ClassPathXmlApplicationContext("applicationContext.xml");
BillService service=(BillService)context.getBean("billServiceImpl"); List<Bill> alls = service.findAlls(); System.out.println("-----------------------------------------------"); List<Bill> a = service.findAlls(); System.out.println(alls.size()); }
applicationContext.xml是我spring的配置文件，管理session
测试结果：
ogging initialized using 'class org.apache.ibatis.logging.stdout.StdOutImpl' adapter. Creating a new SqlSession SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@144e54da] was not registered for synchronization because synchronization is not active JDBC Connection [285401532, URL=jdbc:mysql:///supermarket_ssh, UserName=root@localhost, MySQL Connector Java] will not be managed by Spring ==> Preparing: select * from bill ==> Parameters: <== Columns: bid, bmoney, bname, createtime, paystate, supId, hscode, scount, sunit <== Row: 24, 150262, 猕猴桃山西, 2017-09-06, 1, 3, ssh-code, 1000, bdss <== Row: 26, 1500, 苹果梨山西, 2017-08-25, 0, 1, ssh-code, 50, bdss <== Row: 27, 150262, 苹果梨山西, 2017-08-25, 0, 1, ssh-code, 1000, bdss <== Row: 29, 2561, xx, 2017-08-25, 0, 1, ssh-code, 0, bdss <== Row: 30, 3642, aa, 2017-08-25, 0, 1, ssh-code, 1000, 56ds3fs <== Row: 31, 0, bb, 2017-08-25, 0, 3, ssh-code, 52, bdss <== Row: 33, 3335, aa, 2017-08-25, 0, 3, ssh-code, 1000, 56ds3fs <== Row: 41, 2000, 小炒肉, 2017-09-03, 1, 3, ssh-code, 100, bdqn <== Row: 42, 0, zahngyu, 2017-09-03, 1, 12, ssh-code, 100, bdqn <== Row: 44, 200, 共百搭, 2017-09-06, 1, 3, dsfas, 15, dfa <== Row: 45, 5000, 张雨张雨, 2017-09-06, 0, 14, ssh-supmarket, 50, bdqn <== Row: 49, 0, dfaf, 2017-09-09, 0, 1, s-code, 3, dfa <== Row: 50, 0, 宫保鸡丁, 2017-09-10, 0, 1, gbjd-code, 2, bdqn <== Row: 52, 0, f'da, 2017-09-10, 1, 1, f'da, 5, f'da <== Row: 55, 0, hznagu, 2017-09-10, 1, 1, ssh-code, 25, bdqn <== Row: 56, 0, 宫保鸡丁, 2017-09-10, 0, 1, ssj-code, 2, bdqn <== Row: 57, 0, dfa, 2017-09-10, 1, 1, dfa, 2, fda <== Row: 58, 0, fda, 2017-09-10, 0, 1, dfa, 25, dfa <== Row: 59, 0, dfa, 2017-09-10, 0, 1, fda, 2, dfa <== Total: 19 Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@144e54da] 19 ----------------------------------------------- Creating a new SqlSession SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@d68b796] was not registered for synchronization because synchronization is not active JDBC Connection [1441587130, URL=jdbc:mysql:///supermarket_ssh, UserName=root@localhost, MySQL Connector Java] will not be managed by Spring ==> Preparing: select * from bill ==> Parameters: <== Columns: bid, bmoney, bname, createtime, paystate, supId, hscode, scount, sunit <== Row: 24, 150262, 猕猴桃山西, 2017-09-06, 1, 3, ssh-code, 1000, bdss <== Row: 26, 1500, 苹果梨山西, 2017-08-25, 0, 1, ssh-code, 50, bdss <== Row: 27, 150262, 苹果梨山西, 2017-08-25, 0, 1, ssh-code, 1000, bdss <== Row: 29, 2561, xx, 2017-08-25, 0, 1, ssh-code, 0, bdss <== Row: 30, 3642, aa, 2017-08-25, 0, 1, ssh-code, 1000, 56ds3fs <== Row: 31, 0, bb, 2017-08-25, 0, 3, ssh-code, 52, bdss <== Row: 33, 3335, aa, 2017-08-25, 0, 3, ssh-code, 1000, 56ds3fs <== Row: 41, 2000, 小炒肉, 2017-09-03, 1, 3, ssh-code, 100, bdqn <== Row: 42, 0, zahngyu, 2017-09-03, 1, 12, ssh-code, 100, bdqn <== Row: 44, 200, 共百搭, 2017-09-06, 1, 3, dsfas, 15, dfa <== Row: 45, 5000, 张雨张雨, 2017-09-06, 0, 14, ssh-supmarket, 50, bdqn <== Row: 49, 0, dfaf, 2017-09-09, 0, 1, s-code, 3, dfa <== Row: 50, 0, 宫保鸡丁, 2017-09-10, 0, 1, gbjd-code, 2, bdqn <== Row: 52, 0, f'da, 2017-09-10, 1, 1, f'da, 5, f'da <== Row: 55, 0, hznagu, 2017-09-10, 1, 1, ssh-code, 25, bdqn <== Row: 56, 0, 宫保鸡丁, 2017-09-10, 0, 1, ssj-code, 2, bdqn <== Row: 57, 0, dfa, 2017-09-10, 1, 1, dfa, 2, fda <== Row: 58, 0, fda, 2017-09-10, 0, 1, dfa, 25, dfa <== Row: 59, 0, dfa, 2017-09-10, 0, 1, fda, 2, dfa <== Total: 19 Closing non transactional SqlSession [org.apache.ibatis.session.defaults.DefaultSqlSession@d68b796] [entity.Bill@6afd9125, entity.Bill@2d444b03, entity.Bill@5e98c92c, entity.Bill@bf9839, entity.Bill@22a2c691, entity.Bill@6c9a6b5a, entity.Bill@dfe196a, entity.Bill@25368553, entity.Bill@1e6b1f3b, entity.Bill@acf6a17, entity.Bill@373e118c, entity.Bill@4bf21aa9, entity.Bill@3b47433, entity.Bill@3c38c22b, entity.Bill@3253b3f0, entity.Bill@154a6b60, entity.Bill@48cf768b, entity.Bill@2c6fc505, entity.Bill@5defe20d]
测试结果有点多啊但明显是没有使用到mybatis的一级缓存。
如果我们使用mybatis自己管理的session来看下测试结果
@Test
public void TestBi(){
SqlSession session = MyBatisUtil.getSessionTwo();
BillDao mapper = session.getMapper(BillDao.class);
List<Bill> b1 = mapper.findAlls();
System.out.println(b1.size());
List<Bill> b2 = mapper.findAlls();
System.out.println(b2.size());
Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@6d20ec1b] ==> Preparing: select * from bill ==> Parameters: <== Columns: bid, bmoney, bname, createtime, paystate, supId, hscode, scount, sunit <== Row: 24, 150262, 猕猴桃山西, 2017-09-06, 1, 3, ssh-code, 1000, bdss <== Row: 26, 1500, 苹果梨山西, 2017-08-25, 0, 1, ssh-code, 50, bdss <== Row: 27, 150262, 苹果梨山西, 2017-08-25, 0, 1, ssh-code, 1000, bdss <== Row: 29, 2561, xx, 2017-08-25, 0, 1, ssh-code, 0, bdss <== Row: 30, 3642, aa, 2017-08-25, 0, 1, ssh-code, 1000, 56ds3fs <== Row: 31, 0, bb, 2017-08-25, 0, 3, ssh-code, 52, bdss <== Row: 33, 3335, aa, 2017-08-25, 0, 3, ssh-code, 1000, 56ds3fs <== Row: 41, 2000, 小炒肉, 2017-09-03, 1, 3, ssh-code, 100, bdqn <== Row: 42, 0, zahngyu, 2017-09-03, 1, 12, ssh-code, 100, bdqn <== Row: 44, 200, 共百搭, 2017-09-06, 1, 3, dsfas, 15, dfa <== Row: 45, 5000, 张雨张雨, 2017-09-06, 0, 14, ssh-supmarket, 50, bdqn <== Row: 49, 0, dfaf, 2017-09-09, 0, 1, s-code, 3, dfa <== Row: 50, 0, 宫保鸡丁, 2017-09-10, 0, 1, gbjd-code, 2, bdqn <== Row: 52, 0, f'da, 2017-09-10, 1, 1, f'da, 5, f'da <== Row: 55, 0, hznagu, 2017-09-10, 1, 1, ssh-code, 25, bdqn <== Row: 56, 0, 宫保鸡丁, 2017-09-10, 0, 1, ssj-code, 2, bdqn <== Row: 57, 0, dfa, 2017-09-10, 1, 1, dfa, 2, fda <== Row: 58, 0, fda, 2017-09-10, 0, 1, dfa, 25, dfa <== Row: 59, 0, dfa, 2017-09-10, 0, 1, fda, 2, dfa <== Total: 19 19 19
很明显，只访问了一次数据库，说明单独使用mybatis的 一级缓存是 有效的。
再看看hibernate和 spring整和的情况下，测试hibernate的一级缓存：
@org.junit.Test public void TestOneCache(){ //被spring管理的hibernate 一级缓存失效 ApplicationContext context = new ClassPathXmlApplicationContext("spring-hiberanate.xml"); BillService service= (BillService)context.getBean("billServiceImpl"); List<Bill> allBills = service.findAllBills(); System.out.println(allBills.size()); System.out.println("---------------------------------"); List<Bill> allBillss = service.findAllBills(); System.out.println(allBillss.size()); }
测试结果：
Hibernate: select bill0_.bid as bid1_1_, bill0_.bmoney as bmoney2_1_, bill0_.bname as bname3_1_, bill0_.createtime as createti4_1_, bill0_.hscode as hscode5_1_, bill0_.paystate as paystate6_1_, bill0_.scount as scount7_1_, bill0_.sunit as sunit8_1_, bill0_.supId as supId9_1_ from bill bill0_ Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? 19 --------------------------------- Hibernate: select bill0_.bid as bid1_1_, bill0_.bmoney as bmoney2_1_, bill0_.bname as bname3_1_, bill0_.createtime as createti4_1_, bill0_.hscode as hscode5_1_, bill0_.paystate as paystate6_1_, bill0_.scount as scount7_1_, bill0_.sunit as sunit8_1_, bill0_.supId as supId9_1_ from bill bill0_ Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? 19
和mybatis一样，被spring管理的hibernate 的一级缓存无效。说明问题 出在spring身上。
先看下spring整合mybatis，sessionFactory是由mybatis提供的，进入sqlSessionFactory类内部。
/** * Copyright 2009-2015 the original author or authors. * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.ibatis.session; import java.sql.Connection; /** * Creates an {@link SqlSesion} out of a connection or a DataSource * * @author Clinton Begin */ public interface SqlSessionFactory { SqlSession openSession(); SqlSession openSession(boolean autoCommit); SqlSession openSession(Connection connection); SqlSession openSession(TransactionIsolationLevel level); SqlSession openSession(ExecutorType execType); SqlSession openSession(ExecutorType execType, boolean autoCommit); SqlSession openSession(ExecutorType execType, TransactionIsolationLevel level); SqlSession openSession(ExecutorType execType, Connection connection); Configuration getConfiguration(); }
然后找到它的一个实现类，sqlsessionManager，它同时还实现了SqlSession
** * @author Larry Meadors */ public class SqlSessionManager implements SqlSessionFactory, SqlSession { private final SqlSessionFactory sqlSessionFactory; private final SqlSession sqlSessionProxy; private ThreadLocal<SqlSession> localSqlSession = new ThreadLocal<SqlSession>(); private SqlSessionManager(SqlSessionFactory sqlSessionFactory) { this.sqlSessionFactory = sqlSessionFactory; this.sqlSessionProxy = (SqlSession) Proxy.newProxyInstance( SqlSessionFactory.class.getClassLoader(), new Class[]{SqlSession.class}, new SqlSessionInterceptor()); }
private ThreadLocal<SqlSession> localSqlSession = new ThreadLocal<SqlSession>();这个是让session和当前的线程绑定
关于一级缓存失效的原因还要看他的另一个方法，实现自SqlSession
@Override public Object invoke(Object proxy, Method method, Object[] args) throws Throwable { final SqlSession sqlSession = SqlSessionManager.this.localSqlSession.get(); if (sqlSession != null) { try { return method.invoke(sqlSession, args); } catch (Throwable t) { throw ExceptionUtil.unwrapThrowable(t); } } else { final SqlSession autoSqlSession = openSession(); try { final Object result = method.invoke(autoSqlSession, args); autoSqlSession.commit(); return result; } catch (Throwable t) { autoSqlSession.rollback(); throw ExceptionUtil.unwrapThrowable(t); } finally { autoSqlSession.close(); } } }
//这是close方法 @Override public void close() { final SqlSession sqlSession = localSqlSession.get(); if (sqlSession == null) { throw new SqlSessionException("Error: Cannot close. No managed session is started."); } try { sqlSession.close(); } finally { localSqlSession.set(null); //释放线程 } }
看下红色部分的代码，当一个非空的session传过来，重新 opensession() 在代码执行到最后执行autoSqlSession.close()方法，关闭session，释放线程，跳出递归；
大致总结一下：
session和当前线程绑定的过程以及mybatis失效的原因
1,获得请求
2,spring检查到了这种需求，于是去申请一个mybatis的sqlsession（资源池），并将申请到的sqlsession与当前线程绑定，放入threadlocal里面
3,template从threadlocal获取到sqlsession，去执行查询
4,查询结束，清空threadlocal中与当前线程绑定的sqlsession，释放资源
5,我们又需要访问数据，拿到新的session
6,返回到步骤2
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
@org.junit.Test public void TestOneCache(){ //没有被spring管理使用一级缓存 Session session = HibernateUtil.currentSession(); System.out.println(session); List<Bill> list=session.createQuery( "from Bill ").list(); System.out.println(list.size()); List<Bill> lists = session.createQuery( "from Bill ").list(); System.out.println(lists.size()); //被spring管理的hibernate 一级缓存失效 /*ApplicationContext context = new ClassPathXmlApplicationContext("spring-hiberanate.xml"); BillService service= (BillService)context.getBean("billServiceImpl"); List<Bill> allBills = service.findAllBills(); System.out.println(allBills.size()); System.out.println("---------------------------------"); List<Bill> allBillss = service.findAllBills(); System.out.println(allBillss.size());*/ }
很明显走的缓存
Hibernate: select bill0_.bid as bid1_1_, bill0_.bmoney as bmoney2_1_, bill0_.bname as bname3_1_, bill0_.createtime as createti4_1_, bill0_.hscode as hscode5_1_, bill0_.paystate as paystate6_1_, bill0_.scount as scount7_1_, bill0_.sunit as sunit8_1_, bill0_.supId as supId9_1_ from bill bill0_ Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? 19 Hibernate: select bill0_.bid as bid1_1_, bill0_.bmoney as bmoney2_1_, bill0_.bname as bname3_1_, bill0_.createtime as createti4_1_, bill0_.hscode as hscode5_1_, bill0_.paystate as paystate6_1_, bill0_.scount as scount7_1_, bill0_.sunit as sunit8_1_, bill0_.supId as supId9_1_ from bill bill0_ 19
--被spring管理的hibernate缓存
@org.junit.Test public void TestOneCache(){ //被spring管理的hibernate 一级缓存失效 ApplicationContext context = new ClassPathXmlApplicationContext("spring-hiberanate.xml"); BillService service= (BillService)context.getBean("billServiceImpl"); List<Bill> allBills = service.findAllBills(); System.out.println(allBills.size()); System.out.println("---------------------------------"); List<Bill> allBillss = service.findAllBills(); System.out.println(allBillss.size()); }
Hibernate: select bill0_.bid as bid1_1_, bill0_.bmoney as bmoney2_1_, bill0_.bname as bname3_1_, bill0_.createtime as createti4_1_, bill0_.hscode as hscode5_1_, bill0_.paystate as paystate6_1_, bill0_.scount as scount7_1_, bill0_.sunit as sunit8_1_, bill0_.supId as supId9_1_ from bill bill0_ Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? 19 --------------------------------- Hibernate: select bill0_.bid as bid1_1_, bill0_.bmoney as bmoney2_1_, bill0_.bname as bname3_1_, bill0_.createtime as createti4_1_, bill0_.hscode as hscode5_1_, bill0_.paystate as paystate6_1_, bill0_.scount as scount7_1_, bill0_.sunit as sunit8_1_, bill0_.supId as supId9_1_ from bill bill0_ Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? Hibernate: select supplier0_.supId as supId1_2_0_, supplier0_.createtime as createti2_2_0_, supplier0_.supName as supName3_2_0_, supplier0_.supUserName as supUserN4_2_0_, supplier0_.supUserTel as supUserT5_2_0_, supplier0_.supcode as supcode6_2_0_, supplier0_.supfax as supfax7_2_0_ from supplier supplier0_ where supplier0_.supId=? 19
一级缓存失效
然后看下spring集成的hibernate配置文件，spring+hibernate的sessionFactory是交给spring来管理的，进入配置文件 找到LocalSessionFactory
<bean id="sessionFactory" class="org.springframework.orm.hibernate5.LocalSessionFactoryBean"> <property name="dataSource" ref="dataSource" /> <property name="packagesToScan"> <list> <value>zy.entity</value> </list> </property> <property name="hibernateProperties"> <props> <prop key="hibernate.show_sql">true</prop> </props> </property> </bean>
private static final ThreadLocal<Session> thread=new ThreadLocal<Session>();
hibernate有两个方法获取session，一个是openSession(),一个是getCurrentSession()
a:getCurrentSession创建的session会绑定到当前线程，而openSession不会。
b:getCurrentSession创建的线程会在事务回滚或事务提交后自动关闭，而openSession必须手动关闭
public Session openSession() throws HibernateException { return this.withOptions().openSession(); } public Session openTemporarySession() throws HibernateException { return this.withOptions().autoClose(false).flushBeforeCompletion(false).connectionReleaseMode(ConnectionReleaseMode.AFTER_STATEMENT).openSession(); }
public SessionBuilder autoClose(boolean autoClose) { this.autoClose = autoClose; return this; }
public SessionBuilder flushBeforeCompletion(boolean flushBeforeCompletion) { this.flushBeforeCompletion = flushBeforeCompletion; return this; }
--翻了下他的源码，感觉获得session的过程像个迷宫似的，翻着翻着回来了，貌似回调，不懂，不过我觉得，他是根据请求每次获得session时都“冲洗了”一下，但是我用工具类得到的session也是这样啊
不知道spring到底对hibernate干了什么，让一级缓存失效。你tm到底干了什么？？？？？？/
----希望知道的分享一下 ，非常感谢。