Hibernate cannot get the updated records in the database in real time solve the problem

The project uses Hibernate to connect and manipulate the MySQL database, with a "query" module and a "Add" module, which are made with different hibernate profiles. After the addition after the completion of the query found the problem, the results of the query is always added before, and the latest updated records are not queried. Only restart the Tomcat server to find the updated records.

Google's.

The cache mechanism of hibernate is mentioned on the Internet, http://blog.csdn.net/fjun0910/article/details/6092829

According to it, use Session.clear () before the query, clear the first-level cache, retry adding + queries, or you cannot find the update record. Use Setcachemode (Cachemode.ignore) to clear level two cache, experiment, failure. Two are cleared and still fail.

Is confused, found here: http://blog.sina.com.cn/s/blog_6d818993010137in.html

Although not very clear, but found the problem: Hibernate default Connection pool problems, using the C3P0 connection pool can be. As a result, the following steps are used to resolve the problem:

First add the required jar package: Hibernate-c3p0-4.2.0.final.jar,c3p0-0.9.2.1.jar,mchange-commons-java-0.2.7.jar, can be distributed to/HTTP mvnrepository.com/and http://www.java2s.com/Download, note Mchange-commons-java version not too low, otherwise it will classnotfound wrong.

Modify the Hibernate configuration file, connect to the database with the C3P0 connection pool, and add the following configuration outside of the previous configuration:

<property name= "Hibernate.connection.provider_class" > org.hibernate.connection.c3p0connectionprovider</property>         <property name= "Hibernate.c3p0.max_size" >20</property>         <property name= "Hibernate.c3p0.min_size" >5</property>         <!--  <property name= "Hibernate.c3p0.timeout" >120</ Property>-->        <property name= "AutomaticTestTable" >test</property>        <property name= " Hibernate.c3p0.max_statements ">100</property>        < Property name= "Hibernate.c3p0.idle_test_period" >120</property>         <property name= "Hibernate.c3p0.acquire_increment" >1</properTy>        <property name= "C3p0.testConnectionOnCheckout" >true</property>        <property name= " C3p0.idleconnectiontestperiod ">18000</property>        < Property name= "C3p0.maxidletime" >25000</property>

Solve the problem.

Above.

This article is from the "Wood on the Road" blog, please be sure to keep this source http://mumufairy.blog.51cto.com/6184508/1551220

Hibernate cannot get the updated records in the database in real time solve the problem