Hibernate 一对多双向(Annotation)

[AlenCheng]

今天在做双向一对多 Annotation测试时，出现了一个错误。。找了半天不知道是什么地方出了问题。希望各位高手能帮忙看看，指点指点。

package org.alen.entity;

import java.io.Serializable;
import java.util.HashSet;
import java.util.Set;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.OneToMany;
import javax.persistence.Table;

@Entity
public class Groups implements Serializable{
	
	private String id;
	private String name;
	private Set<User> users = new HashSet<User>();
	
	
	@OneToMany(mappedBy="group")
	public Set<User> getUsers() {
		return users;
	}
	public void setUsers(Set<User> users) {
		this.users = users;
	}
	@Id
	@GeneratedValue
	public String getId() {
		return id;
	}
	public void setId(String id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	
	

}


package org.alen.entity;

import java.io.Serializable;
 
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Table;

@Entity
public class User implements Serializable{
	
	private String id;
	private String name;
	private Groups group;
	
	@Id
	@GeneratedValue
	public String getId() {
		return id;
	}
	public void setId(String id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	
	@ManyToOne
	@JoinColumn(name="gid")
	public Groups getGroup() {
		return group;
	}
	public void setGroup(Groups group) {
		this.group = group;
	}
	
	

}

public class Oper {
	
	public static void main(String[] args) {
		
		Session session = new AnnotationConfiguration().configure().buildSessionFactory().openSession();
		
		Groups group = new Groups();
		group.setName("管理员");
		
		User user = new User();
		user.setName("alen");
		user.setGroup(group);
		
		User user1 = new User();
		user1.setName("tom");
		user1.setGroup(group);
		
		User user2 = new User();
		user2.setName("rose");
		user2.setGroup(group);
		
		group.getUsers().add(user);
		group.getUsers().add(user1);
		group.getUsers().add(user2);
		
		session.save(group);
		session.beginTransaction().commit();
		session.close();
		
	}

}

hibernate.cfg.xml 文件已经配置

错误信息：总是提示我对象名无效。。。

Hibernate: 
    insert 
    into
        Groups
        (name) 
    values
        (?)
Exception in thread "main" org.hibernate.exception.SQLGrammarException: could not insert: [org.alen.entity.Groups]
	at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:67)
	at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:43)
	at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:40)
	at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2153)
	at org.hibernate.persister.entity.AbstractEntityPersister.insert(AbstractEntityPersister.java:2633)
	at org.hibernate.action.EntityIdentityInsertAction.execute(EntityIdentityInsertAction.java:51)
	at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:279)
	at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:298)
	at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:181)
	at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:107)
	at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:187)
	at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:33)
	at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:172)
	at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:27)
	at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:70)
	at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:536)
	at org.hibernate.impl.SessionImpl.save(SessionImpl.java:524)
	at org.hibernate.impl.SessionImpl.save(SessionImpl.java:520)
	at org.alen.util.Oper.main(Oper.java:33)
Caused by: com.microsoft.sqlserver.jdbc.SQLServerException: 对象名 'Groups' 无效。
	at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDatabaseError(Unknown Source)
	at com.microsoft.sqlserver.jdbc.SQLServerStatement.getNextResult(Unknown Source)
	at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.doExecutePreparedStatement(Unknown Source)
	at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement$PrepStmtExecCmd.doExecute(Unknown Source)
	at com.microsoft.sqlserver.jdbc.TDSCommand.execute(Unknown Source)
	at com.microsoft.sqlserver.jdbc.SQLServerConnection.executeCommand(Unknown Source)
	at com.microsoft.sqlserver.jdbc.SQLServerStatement.executeCommand(Unknown Source)
	at com.microsoft.sqlserver.jdbc.SQLServerStatement.executeStatement(Unknown Source)
	at com.microsoft.sqlserver.jdbc.SQLServerPreparedStatement.executeUpdate(Unknown Source)
	at org.hibernate.id.IdentityGenerator$GetGeneratedKeysDelegate.executeAndExtract(IdentityGenerator.java:73)
	at org.hibernate.id.insert.AbstractReturningDelegate.performInsert(AbstractReturningDelegate.java:33)
	... 16 more