利用Hibernate注解生成表
Hibernate4注释
@Entity(name = "tbl_user") 将一个类声明为一个实体bean(即一个持久化POJO类)
@Id注解则声明了该实体bean的标识属性，必填属性
@GenericGeneratorhibernate在JPA的基础上进行了扩展，可以用一下方式引入hibernate独有的主键生成策略。
@Column name解决属性名和字段名不对应 length限制字符串长度 unique , nullable , precision 数据长度, scale 无小数
hibernate.cfg.xml
mysql
jdbc:mysql://localhost:3306/forums
root
root
com.mysql.jdbc.Driver
thread
org.hibernate.dialect.MySQLDialect
true
thread
update
org.hibernate.c3p0.internal.C3P0ConnectionProvider
20
5
120
3000
package csdn.forum.util;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
public class HibernateSessionFactory {
static Configuration cfg;
static SessionFactory sessionFactory;
static ServiceRegistry serviceRegistry;
static {
cfg = new Configuration().configure();// 默认找文件hibernate.hbm.xml
// 创建服务注册对象
serviceRegistry = new StandardServiceRegistryBuilder().applySettings(
cfg.getProperties()).build();
// 创建Factory工厂
sessionFactory = cfg.buildSessionFactory(serviceRegistry);
}
// 获取session对象
public static Session getSession() {
// 打开session
return sessionFactory.getCurrentSession();
}
} fetch在Hibernate里用时默认值：FetchType.LAZY，它要求程序运行时延迟加载所有的集合和实体。
fetch设置为FetchType.EAGER，它提示程序在首次访问数据时应马上加载所有的集合和实体mappedBy默认值：如果关系是单向的，则该关联提供程序确定拥有该关系的字段。如果关系是双向的，则将关联相反（非拥有）方上的mappedBy元素设置为拥有此关系的字段或属性的名称
@BatchSize(size=10) 对查询抓取的优化方案，通过指定一个主键或外键列表，Hibernate使用单条SELECT语句获取一批对象实例或集合。
package csdn.forum.model;
import java.util.ArrayList;
import java.util.List;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import org.hibernate.annotations.GenericGenerator;
@Entity(name = "tbl_board")
public class TblBoard {
private String id;
private String name;
private TblBoard parentBoard;
private List board = new ArrayList();
private List topics=new ArrayList();
// @id必填
@GenericGenerator(name = "generator", strategy = "uuid.hex")
// hibernate独有的16进制算法
@Id
@GeneratedValue(generator = "generator")
@Column(name = "id", unique = true, nullable = false, length = 32)
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
@Column(name ="name")
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@ManyToOne(cascade = {CascadeType.ALL})
@JoinColumn(name = "parent_id")
public TblBoard getParentBoard() {
return parentBoard;
}
public void setParentBoard(TblBoard parentBoard) {
this.parentBoard = parentBoard;
}
@OneToMany(cascade = {CascadeType.ALL},fetch = FetchType.LAZY,mappedBy = "parentBoard")//在1这方加入@OneToMany(cascade = {CascadeType.ALL},mappedBy = "user") ，只调用session.sa//ve(user);
//在多这方加入@ManyToOne(cascade = {CascadeType.ALL}) @JoinColumn(name = "user_id")，只调用s//ession.save(topic);
public List getBoard() {
return board;
}
public void setBoard(List board) {
this.board = board;
}
@OneToMany(cascade = {CascadeType.ALL},fetch = FetchType.LAZY,mappedBy = "board")
public List getTopics() {
return topics;
}
public void setTopics(List topics) {
this.topics = topics;
}
} 
TblReply.Java
package csdn.forum.model;
import java.util.Date;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import org.hibernate.annotations.GenericGenerator;
@Entity(name = "tbl_reply")
public class TblReply{
private String id;
private String title;
private String content;
private Date publishTime;
private Date modifyTime;
private TblUser user;
private TblTopic tblTopic;
@GenericGenerator(name = "generator", strategy = "uuid.hex")
@Id
@GeneratedValue(generator = "generator")
@Column(name = "id", unique = true, nullable = false, length = 32)
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
@Column(name = "title", length = 32)
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
@Column(name = "content", length = 2000)
public String getContent() {
return content;
}
public void setContent(String content) {
this.content = content;
}
@Temporal(TemporalType.DATE)
@Column(name = "publishTime")
public Date getPublishTime() {
return publishTime;
}
public void setPublishTime(Date publishTime) {
this.publishTime = publishTime;
}
@Temporal(TemporalType.DATE)
@Column(name = "modifyTime")
public Date getModifyTime() {
return modifyTime;
}
public void setModifyTime(Date modifyTime) {
this.modifyTime = modifyTime;
}
@ManyToOne(cascade = {CascadeType.ALL})
@JoinColumn(name = "user_id")
public TblUser getUser() {
return user;
}
public void setUser(TblUser user) {
this.user = user;
}
@ManyToOne(cascade = {CascadeType.ALL})
@JoinColumn(name = "topic_id")
public TblTopic getTblTopic() {
return tblTopic;
}
public void setTblTopic(TblTopic tblTopic) {
this.tblTopic = tblTopic;
}
} 
TblTopic.java
package csdn.forum.model;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.OneToMany;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import org.hibernate.annotations.BatchSize;
import org.hibernate.annotations.GenericGenerator;
@Entity(name = "tbl_topic")
public class TblTopic {
private String id;
private String title;
private String content;
private Date pubishTime;
private Date modifyTime;
private TblUser user;
private TblBoard board;
private List replys=new ArrayList();
@GenericGenerator(name = "generator", strategy = "uuid.hex")
@Id
@GeneratedValue(generator = "generator")
@Column(name = "id", unique = true, nullable = false, length = 32)
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
@Column(name = "title", length = 32)
public String getTitle() {
return title;
}
public void setTitle(String title) {
this.title = title;
}
@Column(name = "content", length = 2000)
public String getContent() {
return content;
}
public void setContent(String content) {
this.content = content;
}
@Temporal(TemporalType.DATE)
@Column(name = "publishTime")
public Date getPubishTime() {
return pubishTime;
}
public void setPubishTime(Date pubishTime) {
this.pubishTime = pubishTime;
}
@Temporal(TemporalType.DATE)
@Column(name = "modifyTime")
public Date getModifyTime() {
return modifyTime;
}
public void setModifyTime(Date modifyTime) {
this.modifyTime = modifyTime;
}
// 多这方映射user_id
@ManyToOne(cascade = {CascadeType.ALL})
@JoinColumn(name = "user_id")
public TblUser getUser() {
return user;
}
public void setUser(TblUser user) {
this.user = user;
}
@OneToMany(cascade = {CascadeType.ALL},fetch = FetchType.LAZY,mappedBy = "tblTopic")
public List getReplys() {
return replys;
}
public void setReplys(List replys) {
this.replys = replys;
}
@ManyToOne(cascade = {CascadeType.ALL})
@JoinColumn(name = "board_id")
public TblBoard getBoard() {
return board;
}
public void setBoard(TblBoard board) {
this.board = board;
}
}
TblUser.java
package csdn.forum.model;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import javax.persistence.CascadeType;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.FetchType;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.OneToMany;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
import org.hibernate.annotations.GenericGenerator;
@Entity(name="tbl_user")
public class TblUser {
/**
*
*/
private static final long serialVersionUID = 1L;
private String id;
private String uname;
private String upass;
private String head;
private Date regTime;
private boolean gender;
private List topic=new ArrayList();
private List replies=new ArrayList();
//@id必填
@GenericGenerator(name = "generator", strategy = "uuid.hex")//hibernate独有的16进制算法
@Id
@GeneratedValue(generator = "generator")
@Column(name = "id", unique = true, nullable = false, length = 32)
public String getId() {
return id;
}
public void setId(String id) {
this.id = id;
}
@Column (name="uname",length=20)
public String getUname() {
return uname;
}
public void setUname(String uname) {
this.uname = uname;
}
@Column (name="upass",length=20)
public String getUpass() {
return upass;
}
public void setUpass(String upass) {
this.upass = upass;
}
@Column (name="head")
public String getHead() {
return head;
}
public void setHead(String head) {
this.head = head;
}
@Temporal(TemporalType.DATE)
@Column(name = "regTime")
public Date getRegTime() {
return regTime;
}
public void setRegTime(Date regTime) {
this.regTime = regTime;
}
@Column(name="gender",length=20)
public boolean isGender() {
return gender;
}
public void setGender(boolean gender) {
this.gender = gender;
}
//现在是一的一方直接通过它映射user,user是多的这一方的属性
// @OneToMany(mappedBy="user")
@OneToMany(cascade = {CascadeType.ALL},fetch = FetchType.LAZY,mappedBy = "user")
public List getTopic() {
return topic;
}
public void setTopic(List topic) {
this.topic = topic;
}
@OneToMany(cascade={CascadeType.ALL},fetch=FetchType.LAZY,mappedBy="user")
public List getReplies() {
return replies;
}
public void setReplies(List replies) {
this.replies = replies;
}
} 
测试类TestUser.java
package csdn.forum.test;
import java.util.Date;
import java.util.List;
import org.hibernate.Query;
import org.hibernate.Session;
import org.junit.Test;
import csdn.forum.model.TblBoard;
import csdn.forum.model.TblReply;
import csdn.forum.model.TblTopic;
import csdn.forum.model.TblUser;
import csdn.forum.util.HibernateSessionFactory;
public class TestUser {
@Test
public void save() {
Session session = HibernateSessionFactory.getSession();
session.getTransaction().begin();
/*
* //1.保存java板块包含jsp,ajax,struts2,hiberante子版块 TblBoard java =new
* TblBoard(); java.setName("java");
*
* TblBoard jsp =new TblBoard(); jsp.setName("jsp"); TblBoard struts2
* =new TblBoard(); struts2.setName("struts2"); TblBoard hiberante =new
* TblBoard(); hiberante.setName("hiberante"); //相互持有
* java.getBoard().add(jsp); java.getBoard().add(struts2);
* java.getBoard().add(hiberante); jsp.setParentBoard(java);
* struts2.setParentBoard(java); hiberante.setParentBoard(java);
*
*
* session.save(java); session.getTransaction().commit();
*/
// 2.利用csdn用户身份，在struts2板块下发表帖子
/*
* TblUser user=new TblUser(); user.setUname("csdn"); TblBoard
* struts2=(TblBoard
* )session.get(TblBoard.class,"2c96c05e44da48600144da4861f60002");
* TblTopic topic=new TblTopic(); topic.setTitle("struts TblBoard");
* topic.setUser(user); topic.setBoard(struts2); topic.setPubishTime(new
* Date()); user.getTopic().add(topic); session.save(topic);
* session.getTransaction().commit();
*/
/*
* //3.利用admin用户身份，给帖子回帖 TblUser user=new TblUser();
* user.setUname("admin"); TblTopic topic1=(TblTopic)
* session.get(TblTopic.class,"2c96c05e44da44660144da4469390000");
* TblReply reply=new TblReply(); reply.setTitle("reply title");
* reply.setUser(user); user.getReplies().add(reply);
* reply.setTblTopic(topic1); topic1.getReplys().add(reply);
* session.getTransaction().commit();
*/
// 4.利用admin用户身份，修改回帖内容
/*
* Query query=session.createQuery(
* "from csdn.forum.model.TblReply r where r.user.uname='admin'");
* TblReply reply=(TblReply) query.list().get(0);
* reply.setTitle("update"); session.save(reply);
* session.getTransaction().commit();
*/
// 5.利用admin用户身份，查看回帖//根据帖子查看回帖，查看下面的所有回帖
/*
* Query query=session.createQuery(
* "from csdn.forum.model.TblReply t where t.user.uname='admin'");
* List lisst=query.list();
*
* for(TblReply tabl:lisst){ System.out.println("1111111111111");
* System.out.println(tabl.getContent()); }
* session.getTransaction().commit();
*/
// 6.利用csdn用户身份,删除回帖，条件限制为有回帖存在不允许删除
/*
* Query query1=session.createQuery(
* "from csdn.forum.model.TblTopic t where t.user.uname='csdn'");
* TblTopic topic1=(TblTopic) query1.list().get(0);
* if(topic1.getReplys().size()==0){ session.delete(topic1); }else{
* System.out.println("提示不能删除"); }
*
* session.getTransaction().commit();
*/
// 7.统计struts2板块下的发帖数
// Query
// query2=session.createQuery("select count(*) from csdn.forum.model.TblTopic t where t.board.name='struts2'");
/*
* Query query2 = session.createQuery(
* " from csdn.forum.model.TblTopic t where t.board.name='struts2'");
*
* System.out.println(query2.list().size()+"---"); //
* System.out.println(query2.list().get(0)); //
* System.out.println(query2.list().get(1)); //
* System.out.println(query2.list().get(2));
* session.getTransaction().commit();
*/
// 8.查询struts2板块下所有帖子按时间倒序排列
/*
* Query query=session.createQuery(
* "from csdn.forum.model.TblTopic t where t.board.name='struts2' order by t.pubishTime desc"
* ); //System.out.println(query); for(int
* i=0;i 