我有一个带有 c3p0 的休眠持久层，它在 Tomcat 上运行。我有太多连接的问题。在只有少数用户访问该站点后，它开始增加与数据库的连接。我尝试将 maxConnectionAge 更改为 0，我已将 max_pool_size 更改为 0。根据许多站点的建议，我已经弄乱了很多 c3p0 设置，而人们也遇到了同样的问题。但是，似乎没有任何帮助，最终数据库获得了太多连接并且应用程序停止运行。我希望有人可能有一些其他的见解可能会有所帮助。下面是一些相关的代码。
休眠.cfg.xml
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.password">ibisalibi1</property>
<property name="hibernate.connection.url">jdbc:mysql://ikidhub-db-1.cvo0kkopzfhs.us-west-1.rds.amazonaws.com/homemoviezoo</property>
<property name="hibernate.connection.username">rjdamore</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="log4jdbc.drivers">jdbc:log4jdbc:mysql://ikidhub-db-1.cvo0kkopzfhs.us-west-1.rds.amazonaws.com/homemoviezoo</property>
<!-- configuration pool via c3p0-->
<property name="c3p0.acquire_increment">1</property>
<property name="c3p0.idle_test_period">800</property> <!-- seconds -->
<property name="c3p0.max_size">1</property>
<property name="c3p0.max_statements">20</property>
<property name="c3p0.min_size">1</property>
<property name="c3p0.timeout">1800</property> <!-- seconds -->
<property name="c3p0.maxConnectionAge">0</property>
<property name="connection.provider_class">
org.hibernate.service.jdbc.connections.internal.C3P0ConnectionProvider</property>
<property name="transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory</property>
<property name="current_session_context_class">thread</property>
<property name="hibernate.show_sql">true</property>
<!-- <property name="hbm2ddl.auto">update</property>-->
<mapping class="com.local.shared.School"/>
<mapping class="com.local.shared.SchoolVideo"/>
<mapping class="com.local.shared.Category"/>
<mapping class="com.local.shared.Administrator"/>
</session-factory>
</hibernate-configuration>
SessionFactoryUtil
public class SessionFactoryUtil {
private static SessionFactory sessionFactory;
private static ServiceRegistry serviceRegistry;
private static SessionFactory configureSessionFactory()
throws HibernateException {
Configuration configuration = new Configuration();
configuration.configure();
serviceRegistry = new ServiceRegistryBuilder()
.applySettings(configuration.getProperties())
.buildServiceRegistry();
sessionFactory = configuration.buildSessionFactory(serviceRegistry);
return sessionFactory;
}
public static SessionFactory getInstance() {
return configureSessionFactory();
//return sessionFactory;
}
public Session getCurrentSession() {
return sessionFactory.getCurrentSession();
}
public static void close() {
if (sessionFactory != null) {
sessionFactory.close();
sessionFactory = null;
}
}
}
我的 db_access_class 中的一个典型方法
@Override
public School loadSchoolInfo(School schoolInfo) {
Transaction tx = null;
Session session = SessionFactoryUtil.getInstance().getCurrentSession();
try {
tx = session.beginTransaction();
School school = new School();
String admin = schoolInfo.getAdministrator_name();
Query q1 = (Query) session.getNamedQuery("school.admin");
q1.setParameter("admin", admin);
for (Iterator<?> iter = q1.iterate(); iter.hasNext();)
school = (School) iter.next();
schoolInfo.setAdministrator_name((school.getAdministrator_name()));
schoolInfo.setEmail((school.getEmail()));
schoolInfo.setSchool_name((school.getSchool_name()));
tx.commit();
} catch (RuntimeException e) {
if (tx != null && tx.isActive()) {
try {
tx.rollback();
} catch (HibernateException e1) {
e1.printStackTrace();
}
throw e;
}
} finally {
if (session != null) {
if (session.isOpen())
session.close();
}
}
return schoolInfo;
}