hibernate - 休眠连接池

Question

我似乎无法休眠以使用 c3p0 进行连接池，它说

12:30:35,038  INFO DriverManagerConnectionProvider:64 - Using Hibernate built-in connection pool (not for production use!)
12:30:35,038  INFO DriverManagerConnectionProvider:65 - Hibernate connection pool size: 20

休眠配置：

<hibernate-configuration>
  <session-factory>
      <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
      <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/xxx?autoReconnect=true</property>
      <property name="hibernate.connection.username">root</property>
      <property name="hibernate.connection.password">xxxx</property>
      <property name="show_sql">false</property>
      <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
      <property name="hibernate.hbm2ddl.auto">update</property>
      <property name="hibernate.c3p0.min_size">5</property>
      <property name="hibernate.c3p0.max_size">200</property>
      <property name="hibernate.c3p0.max_statements">200</property>
      <property name="current_session_context_class">thread</property>
  </session-factory>
</hibernate-configuration>

Answer 1

<!DOCTYPE hibernate-configuration PUBLIC
  "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
  "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>

        <!-- datasource config -->
        <property name="connection.url">jdbc:mysql://localhost:3306/db?useUnicode=true&amp;characterEncoding=UTF-8&amp;autoReconnect=true</property>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>

        <property name="connection.username">user</property>
        <property name="connection.password">pass</property>

        <!-- c3p0 config http://www.hibernate.org/214.html -->
        <property name="connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property>        
        <property name="hibernate.c3p0.acquire_increment">1</property>
        <property name="hibernate.c3p0.idle_test_period">60</property>
        <property name="hibernate.c3p0.min_size">1</property>
        <property name="hibernate.c3p0.max_size">2</property>
        <property name="hibernate.c3p0.max_statements">50</property>
        <property name="hibernate.c3p0.timeout">0</property>
        <property name="hibernate.c3p0.acquireRetryAttempts">1</property>
        <property name="hibernate.c3p0.acquireRetryDelay">250</property>

        <property name="hibernate.show_sql">true</property>
        <property name="hibernate.use_sql_comments">true</property>

        <property name="hibernate.transaction.factory_class">org.hibernate.transaction.JDBCTransactionFactory</property>
        <property name="hibernate.current_session_context_class">thread</property>

        ...

    </session-factory>
</hibernate-configuration>

Answer 2

解决这些 DTD（文档类型定义）映射问题的最佳方法是

1. 获取hibernate jar 文件并解压缩/jar 并获取两个文件——hibernate-configuration dtd 文件和hibernate-mapping dtd 文件。

2. 从这两个文件中复制 DTD 声明，并分别在 cfg.xml 和 hbm.xml 中使用它们。