hibernate复合主键的问题

kanokano — Mon, 21 Apr 2008 08:53:34 +0800

作者: kanokano 链接：http://kanokano.javaeye.com/blog/184701 发表时间: 2008年04月21日

声明：本文系JavaEye网站发布的原创博客文章，未经作者书面许可，严禁任何网站转载本文，否则必将追究法律责任！

pojo类
package bbb;

/**
* TCode entity.
*
* @author MyEclipse Persistence Tools
*/

public class TCode implements java.io.Serializable {

// Fields

private TCodeId id;
private String mc;
private String dm;
private Byte yn;
private String bz;

// Constructors

/** default constructor */
public TCode() {
}

/** minimal constructor */
public TCode(TCodeId id, String mc, Byte yn) {
this.id = id;
this.mc = mc;
this.yn = yn;
}

/** full constructor */
public TCode(TCodeId id, String mc, String dm, Byte yn, String bz) {
this.id = id;
this.mc = mc;
this.dm = dm;
this.yn = yn;
this.bz = bz;
}

// Property accessors

public TCodeId getId() {
return this.id;
}

public void setId(TCodeId id) {
this.id = id;
}

public String getMc() {
return this.mc;
}

public void setMc(String mc) {
this.mc = mc;
}

public String getDm() {
return this.dm;
}

public void setDm(String dm) {
this.dm = dm;
}

public Byte getYn() {
return this.yn;
}

public void setYn(Byte yn) {
this.yn = yn;
}

public String getBz() {
return this.bz;
}

public void setBz(String bz) {
this.bz = bz;
}

}

复合id类

package bbb;

/**
* TCodeId entity.
*
* @author MyEclipse Persistence Tools
*/

public class TCodeId implements java.io.Serializable {

// Fields

private String tid;
private String id;

// Constructors

/** default constructor */
public TCodeId() {
}

/** full constructor */
public TCodeId(String tid, String id) {
this.tid = tid;
this.id = id;
}

// Property accessors

public String getTid() {
return this.tid;
}

public void setTid(String tid) {
this.tid = tid;
}

public String getId() {
return this.id;
}

public void setId(String id) {
this.id = id;
}

public boolean equals(Object other) {
if ((this == other))
return true;
if ((other == null))
return false;
if (!(other instanceof TCodeId))
return false;
TCodeId castOther = (TCodeId) other;

return ((this.getTid() == castOther.getTid()) || (this.getTid() != null
&& castOther.getTid() != null && this.getTid().equals(
castOther.getTid())))
&& ((this.getId() == castOther.getId()) || (this.getId() != null
&& castOther.getId() != null && this.getId().equals(
castOther.getId())));
}

public int hashCode() {
int result = 17;

result = 37 * result
+ (getTid() == null ? 0 : this.getTid().hashCode());
result = 37 * result + (getId() == null ? 0 : this.getId().hashCode());
return result;
}

}

测试类

package ccc;

import java.util.Iterator;
import java.util.List;

import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;

import bbb.TCode;
import bbb.TCodeId;

public class HibernateTest {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
try {
SessionFactory sessionFactory=null;
Session session=null;
Transaction tx = null;
sessionFactory = new Configuration().configure().buildSessionFactory();

session=sessionFactory.openSession();
tx=session.beginTransaction();
TCode code = (TCode) session.load(bbb.TCode.class, tcodeid);
System.out.println(code.getYn());
tx.commit();
session.close();
sessionFactory.close();
} catch (HibernateException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
System.out.println("ok");
}

}

出错信息：

org.hibernate.MappingException: Unknown entity: bbb.TCode
at org.hibernate.impl.SessionFactoryImpl.getEntityPersister(SessionFactoryImpl.java:514)
at org.hibernate.event.def.DefaultLoadEventListener.onLoad(DefaultLoadEventListener.java:66)
at org.hibernate.impl.SessionImpl.fireLoad(SessionImpl.java:862)
at org.hibernate.impl.SessionImpl.load(SessionImpl.java:781)
at org.hibernate.impl.SessionImpl.load(SessionImpl.java:774)
at ccc.HibernateTest.main(HibernateTest.java:54)

我在网上看到的测试方法，可抱错是这样，查了好久都无法解决！！！

当用这种测试方法时：
。。。。。。。。。。。。。。
Query query = session.createQuery("select ttt.bz from bbb.TCode as ttt");
List list = query.list();
System.out.println(list.size());
for(int i= 0;i String bz = (String) list.get(i);
System.out.println(bz);
}
。。。。。。。。。。。。
怎么list。size （）的值为零？谁解释一下？

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[hibernate入门]刚学hibernate就受打击啊！找不到.hbm.xml文件!不会改.

kanokano — Tue, 11 Mar 2008 11:00:12 +0800

作者: kanokano 链接：http://kanokano.javaeye.com/blog/170086 发表时间: 2008年03月11日

声明：本文系JavaEye网站发布的原创博客文章，未经作者书面许可，严禁任何网站转载本文，否则必将追究法律责任！

我明明在项目中看到了hbm.xml文件，可报错就是找不到啊！就简单的小程序，刚学想把数据插入数据库中。

实体类: Student.java:
package util;

public class Student {
private String username;
private String userpwd;
private String userid;
public String getUserid() {
return userid;
}
public void setUserid(String userid) {
this.userid = userid;
}
public String getUsername() {
return username;
}
public void setUsername(String username) {
this.username = username;
}
public String getUserpwd() {
return userpwd;
}
public void setUserpwd(String userpwd) {
this.userpwd = userpwd;
}
}
操作类的方法：

package util;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
public class HibernateOperation {

/**
* @param args
*/
SessionFactory sf;
Session session;
public HibernateOperation(){
Configuration cfg = new Configuration().configure();
sf = cfg.buildSessionFactory();
session = sf.openSession();
}
public void Insert(Student s){
Transaction tran = session.beginTransaction();
tran.begin();
session.save(s);
tran.commit();
session.close();
}
public void Delete(Student s){
Transaction tran = this.session.beginTransaction();
tran.begin();
tran.commit();
session.close();
}
}

测试类：

package util;
public class Test {

/**
* @param args
*/
public static void main(String[] args) {
// TODO Auto-generated method stub
try {
Student student = new Student();
student.setUserid("00006");
student.setUsername("zhongguo");
student.setUserpwd("123");
HibernateOperation ho = new HibernateOperation();
ho.Insert(student);
} catch (RuntimeException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
Student表的映射文件：

"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

hibernate.cfg.xml文件：

"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">

root
jdbc:mysql://localhost:3306/sa
org.hibernate.dialect.MySQLDialect
abc
root
com.mysql.jdbc.Driver
true

出错信息：

log4j:WARN No appenders could be found for logger (org.hibernate.cfg.Environment).
log4j:WARN Please initialize the log4j system properly.
org.hibernate.MappingException: Resource: session/Student.hbm.xml not found
at org.hibernate.cfg.Configuration.addResource(Configuration.java:479)
at org.hibernate.cfg.Configuration.parseMappingElement(Configuration.java:1465)
at org.hibernate.cfg.Configuration.parseSessionFactory(Configuration.java:1433)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1414)
at org.hibernate.cfg.Configuration.doConfigure(Configuration.java:1390)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1310)
at org.hibernate.cfg.Configuration.configure(Configuration.java:1296)
at util.HibernateOperation.(HibernateOperation.java:17)
at util.Test.main(Test.java:14)

不知道怎么该啊？谁能仔细的讲一讲吗？

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