我hibernate已经生成了DAO 后续又加给数据库加入新表再次要生成DAO及POJO需要注意什么？？？？



我自己可能生成出了问题 所以程序报错了
java.lang.ClassCastException: com.po.Users
这是类型转换异常



我的全部财产~  谢谢大家帮帮忙了
问题补充：
我用的是SSH框架。     就是Hibernate反向生成DAO


这个肯定是我第二次生成DAO时错误了   可能是操作失误  还是第2次生成DAO要注意什么
请大家指点


还有1楼的地址无效了~
问题补充：
users


package com.po;

/**
* Users generated by MyEclipse Persistence Tools
*/

public class Users implements java.io.Serializable {

// Fields

private UsersId id;

// Constructors

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

/** full constructor */
public Users(UsersId id) {
this.id = id;
}

// Property accessors

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

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

}




UsersDAO




package com.po;

import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.hibernate.LockMode;
import org.springframework.context.ApplicationContext;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

/**
* Data access object (DAO) for domain model class Users.
*
* @see com.po.Users
* @author MyEclipse Persistence Tools
*/

public class UsersDAO extends HibernateDaoSupport {
private static final Log log = LogFactory.getLog(UsersDAO.class);

// property constants

protected void initDao() {
// do nothing
}

public void save(Users transientInstance) {
log.debug("saving Users instance");
try {
getHibernateTemplate().save(transientInstance);
log.debug("save successful");
} catch (RuntimeException re) {
log.error("save failed", re);
throw re;
}
}

public void delete(Users persistentInstance) {
log.debug("deleting Users instance");
try {
getHibernateTemplate().delete(persistentInstance);
log.debug("delete successful");
} catch (RuntimeException re) {
log.error("delete failed", re);
throw re;
}
}

public Users findById(com.po.UsersId id) {
log.debug("getting Users instance with id: " + id);
try {
Users instance = (Users) getHibernateTemplate().get("com.po.Users",
id);
return instance;
} catch (RuntimeException re) {
log.error("get failed", re);
throw re;
}
}

public List findByExample(Users instance) {
log.debug("finding Users instance by example");
try {
List results = getHibernateTemplate().findByExample(instance);
log.debug("find by example successful, result size: "
+ results.size());
return results;
} catch (RuntimeException re) {
log.error("find by example failed", re);
throw re;
}
}

public List findByProperty(String propertyName, Object value) {
log.debug("finding Users instance with property: " + propertyName
+ ", value: " + value);
try {
String queryString = "from Users as model where model."
+ propertyName + "= ?";
return getHibernateTemplate().find(queryString, value);
} catch (RuntimeException re) {
log.error("find by property name failed", re);
throw re;
}
}

public List findAll() {
log.debug("finding all Users instances");
try {
String queryString = "from Users";
return getHibernateTemplate().find(queryString);
} catch (RuntimeException re) {
log.error("find all failed", re);
throw re;
}
}

public Users merge(Users detachedInstance) {
log.debug("merging Users instance");
try {
Users result = (Users) getHibernateTemplate().merge(
detachedInstance);
log.debug("merge successful");
return result;
} catch (RuntimeException re) {
log.error("merge failed", re);
throw re;
}
}

public void attachDirty(Users instance) {
log.debug("attaching dirty Users instance");
try {
getHibernateTemplate().saveOrUpdate(instance);
log.debug("attach successful");
} catch (RuntimeException re) {
log.error("attach failed", re);
throw re;
}
}

public void attachClean(Users instance) {
log.debug("attaching clean Users instance");
try {
getHibernateTemplate().lock(instance, LockMode.NONE);
log.debug("attach successful");
} catch (RuntimeException re) {
log.error("attach failed", re);
throw re;
}
}

public static UsersDAO getFromApplicationContext(ApplicationContext ctx) {
return (UsersDAO) ctx.getBean("UsersDAO");
}
}




UsersId



package com.po;

/**
* UsersId generated by MyEclipse Persistence Tools
*/

public class UsersId implements java.io.Serializable {

// Fields

private String username;

private String userpass;

// Constructors

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

/** full constructor */
public UsersId(String username, String userpass) {
this.username = username;
this.userpass = userpass;
}

// Property accessors

public String getUsername() {
return this.username;
}

public void setUsername(String username) {
this.username = username;
}

public String getUserpass() {
return this.userpass;
}

public void setUserpass(String userpass) {
this.userpass = userpass;
}

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

return ((this.getUsername() == castOther.getUsername()) || (this
.getUsername() != null
&& castOther.getUsername() != null && this.getUsername()
.equals(castOther.getUsername())))
&& ((this.getUserpass() == castOther.getUserpass()) || (this
.getUserpass() != null
&& castOther.getUserpass() != null && this
.getUserpass().equals(castOther.getUserpass())));
}

public int hashCode() {
int result = 17;
result = 37 * result
+ (getUsername() == null ? 0 : this.getUsername().hashCode());
result = 37 * result
+ (getUserpass() == null ? 0 : this.getUserpass().hashCode());
return result;
}

}



Users.hbm.xml



<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!--
    Mapping file autogenerated by MyEclipse Persistence Tools
-->
<hibernate-mapping>
    <class name="com.po.Users" table="users" schema="dbo" catalog="usernews">
        <composite-id name="id" class="com.po.UsersId">
            <key-property name="username" type="java.lang.String">
                <column name="username" length="20" />
            </key-property>
            <key-property name="userpass" type="java.lang.String">
                <column name="userpass" length="20" />
            </key-property>
        </composite-id>
    </class>
</hibernate-mapping>




都是反向生成的怎么可能错!~
问题补充：
问题已经解决了，谢谢大家了   分给谁呢？
就给第一个帮我的吧        谢谢大家帮忙了