java - 使用 hibernate 模板时 MySql 连接过多？

Question

在对 mysql 进行 100 次点击后，我们得到 com.mysql.jdbc.exceptions.MySQLNonTransientConnectionException:数据源拒绝建立连接，来自服务器的消息:“连接太多”。

<bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" destroy-method="close">

        <property name="driverClassName" value="com.mysql.jdbc.Driver"></property>
        <property name="url" value="jdbc:mysql://localhost:3306/TechDB?createDatabaseIfNotExist=true"></property>
        <property name="username" value="xxxxx"></property>
        <property name="password" value="xxxxx"></property>
        <property name="initialSize" value="30" />
        <property name="maxActive" value="100" />
        <property name="maxWait" value="5" />
        <property name="maxIdle" value="1" />

    </bean>

<bean id="mysessionFactory"
        class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
        <property name="dataSource" ref="dataSource"></property>
        <property name="mappingResources">
            <list>
                <value>jobseeker.hbm.xml</value>
            </list>
        </property>
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">org.hibernate.dialect.MySQLDialect</prop>
                <prop key="hibernate.hbm2ddl.auto">update</prop>
                <prop key="hibernate.show_sql">true</prop>
                <prop key="hibernate.connection.provider_class">org.hibernate.c3p0.internal.C3P0ConnectionProvider</prop>
                <prop key="hibernate.c3p0.min_size">1</prop>
                <prop key="hibernate.c3p0.max_size">19</prop>
                <prop key="hibernate.c3p0.timeout">120</prop>
                <prop key="hibernate.c3p0.max_statements">10</prop>
                <prop key="hibernate.connection.release_mode">after_statement</prop>
                <prop key="hibernate.transaction.auto_close_session">true</prop>
            </props>
        </property>
    </bean>

    <bean id="template" class="org.springframework.orm.hibernate3.HibernateTemplate">
        <property name="sessionFactory" ref="mysessionFactory"></property>
    </bean>

Answer 1

在您的 java 代码中，一旦您为请求提供服务，请确保连接已关闭。

Connection connection = null;
try {
    connection = database.getConnection();
    // the actual code goes here
} finally {
    if (connection != null) try { connection.close(); } catch (SQLException ignore) {}
}