一个简单的HQL问题

代码如下

    Long id = new Long(2);;
    Message message = (Message); session.find("from Message as message where message.id=?", id, Hibernate.LONG);;

这样提示转型出错 id不能转化成Hibernate.LONG
id要定义成什么类型 哪位大虾用过的告知 谢谢

你的message.id是什么类型？

Message.id类型是Long

应该没错呀。
把详细的代码，映射，错误栈贴出。

Message 类

package hello;

public class Message {
  private Long id;
  private String text;
  private Message nextMessage;
  public Message(); {}

  public Message(Long id); {
    this.id = id;
  }

  public Message(String text); {
    this.text = text;
  }

  public Message(Long id, String text); {
    this.id = id;
    this.text = text;
  }

  public Long getId(); {
    return id;
  }

  private void setId(Long id); {
    this.id = id;
  }

  public String getText(); {
    return text;
  }

  public void setText(String text); {
    this.text = text;
  }

  public Message getNextMessage(); {
    return nextMessage;
  }

  public void setNextMessage(Message nextMessage); {
    this.nextMessage = nextMessage;
  }
}


配置文件：

<?xml version="1.0"?>

<!DOCTYPE hibernate-mapping PUBLIC
    "-//Hibernate/Hibernate Mapping DTD 2.0//EN"
    "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">
<hibernate-mapping>
	<class
		name="hello.Message"
		table="Messages"
	>
	<id	name="id"
		column="MESSAGE_ID"
	>
	<generator class="native"/>
	</id>
	<property
		name="text"
		column="MESSAGE_TEXT"
	/>
	<many-to-one
		name="nextMessage"
		cascade="all"
		column="NEXT_MESSAGE_ID"
	/>
	</class>
</hibernate-mapping>




测试类：



package hello;

import net.sf.hibernate.Hibernate;
import net.sf.hibernate.Session;
import net.sf.hibernate.SessionFactory;
import net.sf.hibernate.cfg.Configuration;

/**
 * @author getdown
 * @version 1.0
 */

public class Hello {
  public Hello(); {
  }

  public static void main(String[] args); throws Exception {
    Configuration cfg = new Configuration();.addClass(Message.class);;
    SessionFactory sessions = cfg.buildSessionFactory();;
    Session session = sessions.openSession();;

    Long id = new Long(1);;
    Message message = (Message); session.find("from Message as message where message.id=?", id, Hibernate.LONG);;
    System.out.println(message.getText(););;
    session.close();;
  }

}




错误：



java.lang.ClassCastException



	at hello.Hello.main(Hello.java:23)

Session.list()返回java.util.List

3x 这种小错误居然没有发现

呵呵