java - hibernate 3 : unable to query PostgreSQL database

Question

我正在使用 Hibernate 3.3.1 GA 和 PostgreSQL 8.3 建立一个项目。我刚刚创建了一个数据库，第一个表，在那里添加了一行，现在正在配置 Hibernate。

然而，即使是最简单的查询:

Criteria criteria = session.createCriteria(Place.class);
List result = criteria.list();

无法执行(数据库中只有一条记录，但返回空列表)。我查看了 PostgreSQL 日志:

2008-09-17 22:52:59 CEST LOG:  connection received: host=192.168.175.1 port=2670  
2008-09-17 22:52:59 CEST LOG:  connection authorized: user=... database=...  
2008-09-17 22:53:00 CEST LOG:  execute <unnamed>: SHOW TRANSACTION ISOLATION LEVEL  
2008-09-17 22:53:02 CEST LOG:  could not receive data from client: Connection reset by peer  
2008-09-17 22:53:02 CEST LOG:  unexpected EOF on client connection  
2008-09-17 22:53:02 CEST LOG:  disconnection: session time: 0:00:03.011 user=... database=... host=192.168.175.1 port=2670

我使用纯 JDBC 编写了一个简单的程序来获取相同的数据并且它运​​行良好。本例中的 PostgreSQL 日志如下所示(用于比较):

2008-09-17 22:52:24 CEST LOG:  connection received: host=192.168.175.1 port=2668  
2008-09-17 22:52:24 CEST LOG:  connection authorized: user=... database=...  
2008-09-17 22:52:25 CEST LOG:  execute <unnamed>: SELECT * from PLACE  
2008-09-17 22:52:25 CEST LOG:  disconnection: session time: 0:00:00.456 user=... database=... host=192.168.175.1 port=2668  

Hibernate 调试日志没有指示任何错误。如果我接受日志中列出的查询:

15:17:01,859 DEBUG org.hibernate.loader.entity.EntityLoader: Static select for entity com.example.data.Place: select place0_.ID as ID0_0_, place0_.NAME as NAME0_0_, place0_.LATITUDE as LATITUDE0_0_, place0_.LONGITUDE as LONGITUDE0_0_ from PLACE place0_ where place0_.ID=?

and execute it agains the database in the psql, it works (this means that Hibernate has generated a proper SQL).

Below is the Hibernate configuration:

<hibernate-configuration>
    <session-factory>
        <property name="hibernate.connection.url">jdbc:postgresql://192.168.175.128:5433/...</property>
        <property name="hibernate.connection.driver_class">org.postgresql.Driver</property>
        <property name="hibernate.connection.username">...</property>
        <property name="hibernate.connection.password">...</property>
        <property name="dialect">org.hibernate.dialect.PostgreSQLDialect</property>
        <property name="hibernate.show_sql">true</property>
        <property name="hibernate.use_outer_join">true</property>

        <mapping resource="com/example/data/Place.hbm.xml"/>
    </session-factory>
</hibernate-configuration>

...和映射文件:

<hibernate-mapping package="com.example.data">
    <class name="com.example.data.Place" table="PLACE">
        <id column="ID" name="id" type="java.lang.Integer">
            <generator class="native"/>
        </id>
        <property column="NAME" name="name" not-null="true" type="java.lang.String">
            <meta attribute="use-in-tostring">true</meta>
        </property>
        <property column="LATITUDE" name="latitude" not-null="true" type="java.lang.Float">
            <meta attribute="use-in-tostring">true</meta>
        </property>
        <property column="LONGITUDE" name="longitude" not-null="true" type="java.lang.Float">
            <meta attribute="use-in-tostring">true</meta>
        </property>
    </class>
</hibernate-mapping>

用谷歌搜索 unexpected EOF 日志条目并不顺利。任何想法，社区？

Answer 1

对Hibernate代码应用调试器后，它是固定的!

它在问题的文本中不可见，但问题是传递给 createCriteria() 方法的 Place 来自另一个包，而不是 com/example/data，在配置 XML 文件中指定。

Hibernate 调用 Class.isAssignableFrom()，如果返回 false，它会静默退出，从而中断连接。我将就此事为 Hibernate 开发人员开票。