And*_*uer 2 database hibernate java-ee
我已经坚持了几个星期了,我不知道出了什么问题.因为我已经浪费了这么多时间,所以我非常绝望
我使用下面描述的数据模型(MySQL).我通过reverse engeneering(Eclipse/JBoss Tools)创建了hbm.xml和java类(参见下面的示例).
当我尝试保存推文,单词或事件时,我可以在日志消息中看到生成pk值并且参数绑定正确,但是没有任何内容写入数据库.(请参阅帖子最后的日志消息)
但最奇怪的是,我保存到event_has_words表的对象是完美存储的(使用生成的单词和事件表中的id)!?!?!最重要的是没有异常被抛出!?!
有任何想法吗?我要疯了!
最好的祝福,
约翰
这是一个不起作用的映射:
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
<class name="de.brotkasting.buki.cep.data.hibernate.entities.Event" table="event" catalog="cep1">
<id name="pkEventsId" type="java.lang.Integer">
<column name="PK_Events_Id" />
<generator class="identity" />
</id>
<many-to-one name="sourceSystems" class="de.brotkasting.buki.cep.data.hibernate.entities.SourceSystems" fetch="select">
<column name="SourceSystems_PK_SourceSystems_Id" not-null="true" />
</many-to-one>
<many-to-one name="tweets" class="de.brotkasting.buki.cep.data.hibernate.entities.Tweets" fetch="select">
<column name="Tweets_pk_tweet_id" not-null="true" />
</many-to-one>
<property name="systemTimeStamp" type="timestamp">
<column name="System_Time_Stamp" length="19" not-null="true" />
</property>
</class>
</hibernate-mapping>
Run Code Online (Sandbox Code Playgroud)
和相应的班级:
package de.brotkasting.buki.cep.data.hibernate.entities;
// Generated 28.04.2009 21:24:54 by Hibernate Tools 3.2.4.GA
@Entity
@Table(name = "event", catalog = "cep1")
public class Event implements java.io.Serializable {
/**
*
*/
private static final long serialVersionUID = 3530010885697280401L;
private Integer pkEventsId;
private SourceSystems sourceSystems;
private Tweets tweets;
private Date systemTimeStamp;
public Event() {
}
public Event(SourceSystems sourceSystems, Tweets tweets,
Date systemTimeStamp) {
this.sourceSystems = sourceSystems;
this.tweets = tweets;
this.systemTimeStamp = systemTimeStamp;
}
@Id
@Column(name = "PK_Events_Id", unique = true, nullable = false)
public Integer getPkEventsId() {
return this.pkEventsId;
}
public void setPkEventsId(Integer pkEventsId) {
this.pkEventsId = pkEventsId;
}
@JoinColumn(name = "SourceSystems_PK_SourceSystems_Id", nullable = false)
public SourceSystems getSourceSystems() {
return this.sourceSystems;
}
public void setSourceSystems(SourceSystems sourceSystems) {
this.sourceSystems = sourceSystems;
}
@JoinColumn(name = "Tweets_pk_tweet_id", nullable = false)
public Tweets getTweets() {
return this.tweets;
}
public void setTweets(Tweets tweets) {
this.tweets = tweets;
}
//@Temporal(TemporalType.TIMESTAMP)
@Column(name = "System_Time_Stamp", nullable = false, length = 19)
public Date getSystemTimeStamp() {
return this.systemTimeStamp;
}
public void setSystemTimeStamp(Date systemTimeStamp) {
this.systemTimeStamp = systemTimeStamp;
}
}
Run Code Online (Sandbox Code Playgroud)
并坚持下去
public class TweetPersistence extends HibernateBase {
private static int batchCounter = 0;
private static void store(Object object) throws HibernateException
{
try {
if(session == null)
{
session = sessionFactory.openSession();
}
if(!session.isOpen())
{
session = sessionFactory.openSession();
}
session.save(object);
LoggingConfigurator.getInstance().info("Objekt:" +object);
//flush cache every 20 saved entities
//if(batchCounter%20 == 0)
//{
session.flush();
session.clear();
//}
//increment batchCounter
batchCounter++;
} catch (HibernateException e) {
e.printStackTrace(System.out);
}
}
public static void storeTweet(Tweets tweet) {
try {
if (tweet != null) {
store(tweet);
}
} catch (HibernateException e) {
e.printStackTrace(System.out);
}
}
}
Run Code Online (Sandbox Code Playgroud)
在日志中我可以看到id正确生成
- generated identifier: component[eventsPkEventsId,wordsPkWordListId,position]{position=128, wordsPkWordListId=128, eventsPkEventsId=56}
"数据库事务永远不是可选的,无论您是读取还是写入数据,都必须在事务内部进行与数据库的所有通信"
我建议您将所有持久性操作包含在事务中.例如.
Session session = factory.openSession();
Transaction tx;
try {
tx = session.beginTransaction();
session.save(object);
tx.commit();
}
catch (Exception e) {
if (tx != null) tx.rollback();
throw e;
}
finally {
session.close();
}
Run Code Online (Sandbox Code Playgroud)
| 归档时间: |
|
| 查看次数: |
12045 次 |
| 最近记录: |