小编Uda*_*day的帖子

在hibernate中,我们使用配置和映射xml文件.在xml中,第一行是版本,然后我们指定DOCTYPE DTD行.例:

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

任何人都可以解释一下这是什么意思？我知道DTD是文档类型定义,就像定义xml的语法一样.

我想知道这个陈述中的属性.

我刚接触休眠.当我们说'Hibernate在托管和非托管环境中工作'时,有人能解释一下这意味着什么吗？

什么是托管和非托管环境？

提前致谢,

-Uday

我正在尝试使用mysql配置hibernate.

以下是hibernate.cfg.xml:

<hibernate-configuration>
    <session-factory>    
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/TestDB</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">root123</property>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>


        <property name="hdm2ddl.auto">create</property>property>
        <property name="show_sql">false</property>


        <!-- Use the C3P0 connection pool provider -->
        <property name="hibernate.c3p0.min_size">5</property>
        <property name="hibernate.c3p0.max_size">20</property>
        <property name="hibernate.c3p0.timeout">300</property>
        <property name="hibernate.c3p0.max_statements">50</property>
        <property name="hibernate.c3p0.idle_test_period">3000</property>

        <mapping resource="com/psl/course/Course.hbm.xml"/>

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

但是,我收到了以下错误.堆栈跟踪如下,

15 [main] INFO org.hibernate.cfg.Environment - Hibernate 3.3.1.GA
31 [main] INFO org.hibernate.cfg.Environment - hibernate.properties not found
31 [main] INFO org.hibernate.cfg.Environment - Bytecode provider name : javassist
47 [main] INFO org.hibernate.cfg.Environment - using JDK 1.4 java.sql.Timestamp handling
78 [main] …

我在hibernate中尝试一对一映射,hbm文件和类如下,

Student.hbm.xml:

<hibernate-mapping>
    <class name="com.psl.student.Student" table="STUDENT">
        <meta attribute="class-description">This class contains student details.</meta>
        <id name="studentId" type="long" column="STUDENT_ID">
            <generator class="native" />
        </id>
        <property name="studentName" type="string" length="100"  column="STUDENT_NAME" />
        <one-to-one name="studentAddress" class="com.psl.student.Address" not-null="true" column ="STUDENT_ADDRESS"  />
    </class>
</hibernate-mapping>

Address.hbm.xml:

<hibernate-mapping>
    <class name="com.psl.student.Address" table="ADDRESS">

    <meta attribute="class-description">This class contains the student's address details.</meta>
    <id name="addressId" type="long" column="ADDRESS_ID">
        <generator class="native" />
    </id>

    <property name="street" column="ADDRESS_STREET" type="string" length="250" />
    <property name="city" column="ADDRESS_CITY" type="string" length="50" />
    <property name="state" column="ADDRESS_STATE" type="string" length="50" />
    <property name="zipcode" column="ADDRESS_ZIPCODE" type="string" length="10" /> …