Java 无法连接到Smtp服务器

我有一个简单的SpringHibernate应用程序，我正在使用自连接创建类别。它适用于4个类别，但当我输入5个类别时，它会挂断，事务占用太多时间，请帮助我解决 下面是我的代码

达伊姆普

public void addCategory(Category cat) {
    // TODO Auto-generated method stub
    Session session = this.sessionFactory.openSession();
    Transaction trx = session.beginTransaction();
    Long pid = cat.getParentCategory();
    if (pid != null) {
        Category parentCat = (Category) session.get(Category.class, pid);
        cat.setCategory(parentCat);
    }
    session.save(cat);

    trx.commit();
    System.out.println("done");
}

@Override
public List getCategory() {
    Session session = this.sessionFactory.openSession();
    List<Category> categoryList = session.createQuery("from Category").list();

    return categoryList;
}

hbm文件

 <?xml version="1.0"?>
   <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD  //EN"
  "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

   <hibernate-mapping package="amit.com.model">
    <class name="Category" table="Category">
        <id name="primaryKey" column="primaryKey">
            <generator class="native"/>
        </id>

        <property name="name" column="NAME"></property>
<!--        <property name="parentId" column="PARENT_ID" /> -->
        <many-to-one name="category" class="amit.com.model.Category" column="PARENT_ID"   not-null="false"/>

      <!--   <set name="categories" table="Category" lazy="false" cascade="all-delete-orphan"   inverse="false">
           <key column="parentId"/>
           <one-to-many class="amit.com.model.Category" />
       </set> 
      -->
    </class>    
</hibernate-mapping>

servlet-context.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns:mvc="http://www.springframework.org/schema/mvc"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns="http://www.springframework.org/schema/beans"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xsi:schemaLocation="http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">
    <!-- DispatcherServlet Context: defines this servlet's request-processing infrastructure -->
    <!-- Enables the Spring MVC @Controller programming model -->
    <mvc:annotation-driven />
    <!-- Handles HTTP GET requests for /resources/** by efficiently serving up static resources in the ${webappRoot}/resources directory -->
    <mvc:resources mapping="/resources/**" location="/resources/" />
    <!-- Welcome page  -->
    <mvc:view-controller path="/" view-name="home"/>
    <!-- Resolves views selected for rendering by @Controllers to .jsp resources in the /WEB-INF/views directory -->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/views/" />
        <property name="suffix" value=".jsp" />
    </bean>
    <context:component-scan base-package="amit.com" />
    <bean id="propertyConfigurer"
        class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
        <property name="location">
            <value>WEB-INF/spring/jdbc.properties</value>
        </property>
    </bean>
    <bean id="dataSource"
        class="org.apache.commons.dbcp2.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="${jdbc.driverClassName}" />
        <property name="url" value="${jdbc.databaseurl}" />
        <property name="username" value="${jdbc.username}" />
        <property name="password" value="${jdbc.password}" />
    </bean> 




    <!-- <bean id="dataSource" class="org.apache.commons.dbcp2.BasicDataSource" destroy-method="close">
        <property name="driverClassName" value="com.mysql.jdbc.Driver"/>
        <property name="url" value="jdbc:mysql://localhost:3306/river"/>
        <property name="username" value="root"/>
        <property name="password" value="123"/>
    </bean>  -->

    <bean id="sessionFactory"
        class="org.springframework.orm.hibernate4.LocalSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="configLocation" value="classpath:hibernate.cfg.xml" />
    </bean>

    <tx:annotation-driven />
    <bean id="transactionManager"
        class="org.springframework.orm.hibernate4.HibernateTransactionManager">
        <property name="sessionFactory" ref="sessionFactory" />
    </bean>

    <!-- <bean id="userDao" class="net.codejava.spring.dao.UserDAOImpl">
        <constructor-arg>
            <ref bean="sessionFactory" />
        </constructor-arg>
    </bean> -->     
</beans>

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谢谢

您应该正确处理事务和会话。在异常时回滚事务，在finally块中关闭会话。您可以在这里看到使用会话的简单方法，类com.github.fluent.hibernate.HibernateSessionFactory。这里可以找到一个使用MySQL和Hibernate 5的简单控制台应用程序

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当然，您可以使用DAO模式将会话和事务的工作委托给Spring。

它与smtp有什么关系？