Java Hibernate首次登录失败

我将hibernate用于我的移动应用程序，并成功连接到mysql数据库。 但是在第一次登录数据库时，http请求失败。 我到处找，但没有找到答案。 我知道超时后服务器和数据库停止连接，这就是第一个请求失败的原因。 这是我的hibernate.cfg.xml：

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
    "-//Hibernate/Hibernate Configuration DTD//EN"
    "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>

  <session-factory>
      <property name="connection.url">jdbc:mysql://us-cdbr-iron-east-01.cleardb.net:3306/heroku</property>
      <property name="hibernate.connection.username">
          bbb
      </property>
      <property name="hibernate.connection.password">
          qqq
      </property>
      <property name="hibernate.dialect">
          org.hibernate.dialect.MySQLDialect
      </property>
      <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
      <property name="connection.pool_size">10</property>
      <mapping class="com.example.models.TasksEntity"/>
    <mapping resource="TasksEntity.hbm.xml"/>

      <!-- DB schema will be updated if needed -->
    <!-- <property name="hbm2ddl.auto">update</property> -->
  </session-factory>

</hibernate-configuration>

编辑：我将c3p0配置添加到hibernate.cfg.xml中，但在第一次连接时仍然出现异常：

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
    "-//Hibernate/Hibernate Configuration DTD//EN"
    "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>

  <session-factory>
    <property name="hibernate.connection.username">aa</property>
    <property name="hibernate.connection.password">bb</property>
    <property name="connection.url">jdbc:mysql://us-cdbr-iron-east-01.cleardb.net:3306/heroku</property>
    <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
    <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
    <property name="hibernate.c3p0.acquire_increment">1</property>
    <property name="hibernate.c3p0.idle_test_period">100</property>
    <property name="hibernate.c3p0.max_size">10</property>
    <property name="hibernate.c3p0.max_statements">10</property>
    <property name="hibernate.c3p0.min_size">10</property>
    <property name="hibernate.c3p0.timeout">100</property>

    <mapping class="com.example.models.TasksEntity"/>
    <mapping resource="TasksEntity.hbm.xml"/>

      <!-- DB schema will be updated if needed -->
    <!-- <property name="hbm2ddl.auto">update</property> -->
  </session-factory>

</hibernate-configuration>

aa
bb
jdbc：mysql://us-cdbr-iron-east-01.cleardb.net:3306/heroku
org.hibernate.dialogue.mysqldialogue
com.mysql.jdbc.Driver
1.
100
10
10
10
100

Hibernate

C3P0

连接过期时不会重新连接

---

希望它能帮助你

嘿，谢谢你的回答。我将c3p0添加到hibernate.cfg.xml中，但现在我得到了以下错误：“由以下原因引起：java.lang.ClassNotFoundException:org.hibernate.connection.ConnectionProvider”我需要做什么？我使用Hibernate4.3.6。

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
    "-//Hibernate/Hibernate Configuration DTD//EN"
    "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>

  <session-factory>
    <property name="hibernate.connection.username">aa</property>
    <property name="hibernate.connection.password">bb</property>
    <property name="connection.url">jdbc:mysql://us-cdbr-iron-east-01.cleardb.net:3306/heroku</property>
    <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
    <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
    <property name="hibernate.c3p0.acquire_increment">1</property>
    <property name="hibernate.c3p0.idle_test_period">100</property>
    <property name="hibernate.c3p0.max_size">10</property>
    <property name="hibernate.c3p0.max_statements">10</property>
    <property name="hibernate.c3p0.min_size">10</property>
    <property name="hibernate.c3p0.timeout">100</property>

    <mapping class="com.example.models.TasksEntity"/>
    <mapping resource="TasksEntity.hbm.xml"/>

      <!-- DB schema will be updated if needed -->
    <!-- <property name="hbm2ddl.auto">update</property> -->
  </session-factory>

</hibernate-configuration>