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

<?xml version=‘1.0‘ encoding=‘UTF-8‘?>
<!DOCTYPE hibernate-configuration PUBLIC
          "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
          "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<!-- Generated by MyEclipse Hibernate Tools.                   -->
<hibernate-configuration>

<session-factory>
	<property name="myeclipse.connection.profile">mysql</property>
	<property name="connection.url">
		jdbc:mysql://localhost:3306/forums
	</property>
	<property name="connection.username">root</property>
	<property name="connection.password">root</property>
	<property name="connection.driver_class">
		com.mysql.jdbc.Driver
	</property>
	<property name="hibernate.current_session_context_class">thread</property>
	<property name="dialect">
		org.hibernate.dialect.MySQLDialect
	</property>
	<property name="show_sql">true</property>
	<property name="hibernate.current_session_context_class">thread</property>
	<property name="hibernate.hbm2ddl.auto">update</property>

	<!-- 连接池 配置 c3p0-->
	<property name="hibernate.connection.provider_class">org.hibernate.c3p0.internal.C3P0ConnectionProvider</property>
	<!-- 在连接池中可用数据连接的最大数目 -->
	<property name="hibernate.c3p0.max_size">20</property>
	<!-- 在连接池中可用数据连接的最小数目 -->
	<property name="hibernate.c3p0.min_size">5</property>
	<!-- 设定数据库连接的过期时间，以秒为单位，如果连接池中的某个数据库连接处于空闲状态的时间超过了timeout时间，就会从连接池中清除-->
	<property name="hibernate.c3p0.timeout">120</property>
    <!-- 每3000秒查询所有连接池的空闲连接以秒为单位 -->
	<property name="hibernate.c3p0.idle_test_period">3000</property>

	<!--当连接池里面的连接用完的时候，C3P0一下获取的新的连接数 
	   <property name="hibernate.c3p0.acquire_increment">2</property>  
	 每次都验证连接是否可用 
       <property name="hibernate.c3p0.validate">true</property> -->
	
		<!-- 映射文件引入 -->
     <mapping class="csdn.forum.model.TblUser" />
     <mapping class="csdn.forum.model.TblTopic" /> 
     <mapping class="csdn.forum.model.TblBoard" />
     <mapping class="csdn.forum.model.TblReply" /> 
</session-factory>

</hibernate-configuration>

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<TblBoard> board = new ArrayList<TblBoard>();
    private List<TblTopic> topics=new ArrayList<TblTopic>();
	// @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<TblBoard> getBoard() {
		return board;
	}

	public void setBoard(List<TblBoard> board) {
		this.board = board;
	}
	@OneToMany(cascade = {CascadeType.ALL},fetch = FetchType.LAZY,mappedBy = "board")
	public List<TblTopic> getTopics() {
		return topics;
	}

	public void setTopics(List<TblTopic> 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<TblReply> replys=new ArrayList<TblReply>();
	
	@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<TblReply> getReplys() {
		return replys;
	}
	public void setReplys(List<TblReply> 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<TblTopic>  topic=new ArrayList<TblTopic>();
    private  List<TblReply>  replies=new ArrayList<TblReply>();

	//@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<TblTopic> getTopic() {
		return topic;
	}

	public void setTopic(List<TblTopic> topic) {
		this.topic = topic;
	}

	@OneToMany(cascade={CascadeType.ALL},fetch=FetchType.LAZY,mappedBy="user")
	public List<TblReply> getReplies() {
		return replies;
	}

	public void setReplies(List<TblReply> 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<TblReply> 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<query.list().size();i++){ TblTopic topic=(TblTopic)
		 * query.list().get(i); System.out.println(topic.getTitle()); }
		 */

		// 9.查询帖子下所有回帖，按时间倒序排列
		/*
		 * Query query=session.createQuery(
		 * "from csdn.forum.model.TblReply t where t.tblTopic.title=‘struts  TblBoard‘ order by t.publishTime  desc"
		 * ); //System.out.println(query); for(int
		 * i=0;i<query.list().size();i++){ TblReply topic=(TblReply)
		 * query.list().get(i); System.out.println(topic.getTitle()); }
		 */
		
		
		/*
		 * 
		 * 查询父亲java板块
		 * TblBoard board = (TblBoard) session.get(TblBoard.class,
				"2c96c05e44da48600144da4861dd0000");
		System.out.println(board);
		session.getTransaction().commit();*/
		
		
		
		// 10.查出最后发表帖子标题
		 Query query = session
		 .createQuery("from csdn.forum.model.TblTopic t  order by t.pubishTime  asc");
		 // System.out.println(query);
		 TblTopic topic=(TblTopic) query.list().get(query.list().size()-1);
		 System.out.println(topic.getTitle());
	}
}

利用Hibernate4注释生成表,布布扣,bubuko.com

利用Hibernate4注释生成表