Hibernate是一个开放源代码的对象关系映射框架，它对JDBC进行了非常轻量级的对象封装，它将POJO与数据库表建立映射关系，是一个全自动的orm框架，hibernate可以自动生成SQL语句，自动执行，使得Java程序员可以随心所欲的使用对象编程思维来操纵数据库。 Hibernate可以应用在任何使用JDBC的场合，既可以在Java的客户端程序使用，也可以在Servlet/JSP的Web应用中使用，最具革命意义的是，Hibernate可以在应用EJB的J2EE架构中取代CMP，完成数据持久化的重任。
注解：新闻表和评论表
comment.java
package com.cn.pojo;import java.io.Serializable;import javax.persistence.CascadeType;import javax.persistence.Entity;import javax.persistence.FetchType;import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;import javax.persistence.JoinColumn;import javax.persistence.ManyToOne;import javax.persistence.Table;@Entity@Table(name="t_comment")public class Comment implements Serializable{ ???@Id ???@GeneratedValue(strategy=GenerationType.IDENTITY) ???private Integer id; ???private String commentContent; ???@ManyToOne(cascade=CascadeType.ALL,fetch=FetchType.LAZY,targetEntity=News.class) ???@JoinColumn(name="news_id",nullable=false) ???private News news; ???public Integer getId() { ???????return id; ???} ???public void setId(Integer id) { ???????this.id = id; ???} ???public String getCommentContent() { ???????return commentContent; ???} ???public void setCommentContent(String commentContent) { ???????this.commentContent = commentContent; ???} ???public News getNews() { ???????return news; ???} ???public void setNews(News news) { ???????this.news = news; ???} ???public Comment() { ???????super(); ???} ???public Comment(String commentContent) { ???????super(); ???????this.commentContent = commentContent; ???} ???????}News.java
package com.cn.pojo;import java.io.Serializable;import java.util.HashSet;import java.util.Set;import javax.persistence.CascadeType;import javax.persistence.Entity;import javax.persistence.FetchType;import javax.persistence.GeneratedValue;import javax.persistence.GenerationType;import javax.persistence.Id;import javax.persistence.OneToMany;import javax.persistence.Table;@Entity@Table(name="t_news")public class News implements Serializable{ ???@Id ???@GeneratedValue(strategy=GenerationType.IDENTITY) ???private Integer id; ???private String title; ???private String content; ???@OneToMany(cascade=CascadeType.ALL,fetch=FetchType.LAZY,targetEntity=Comment.class,mappedBy="news") ???private Set<Comment> comments=new HashSet<Comment>(); ???public Integer getId() { ???????return id; ???} ???public void setId(Integer id) { ???????this.id = id; ???} ???public String getTitle() { ???????return title; ???} ???public void setTitle(String title) { ???????this.title = title; ???} ???public String getContent() { ???????return content; ???} ???public void setContent(String content) { ???????this.content = content; ???} ???public News() { ???????super(); ???} ???public News(String title, String content) { ???????super(); ???????this.title = title; ???????this.content = content; ???} ???public Set<Comment> getComments() { ???????return comments; ???} ???public void setComments(Set<Comment> comments) { ???????this.comments = comments; ???} ???????}HibernateSessionFactory.java
package com.cn.utilts;import org.hibernate.HibernateException;import org.hibernate.Session;import org.hibernate.cfg.Configuration;import org.hibernate.service.ServiceRegistry;import org.hibernate.boot.MetadataSources;import org.hibernate.boot.registry.StandardServiceRegistryBuilder;/** * Configures and provides access to Hibernate sessions, tied to the * current thread of execution. ?Follows the Thread Local Session * pattern, see {@link http://hibernate.org/42.html }. */public class HibernateSessionFactory { ???/** ?????* Location of hibernate.cfg.xml file. ????* Location should be on the classpath as Hibernate uses ??????* #resourceAsStream style lookup for its configuration file. ?????* The default classpath location of the hibernate config file is ?????* in the default package. Use #setConfigFile() to update ?????* the location of the configuration file for the current session. ???????*/ ???private static final ThreadLocal<Session> threadLocal = new ThreadLocal<Session>(); ???private static org.hibernate.SessionFactory sessionFactory; ???????private static Configuration configuration = new Configuration(); ???private static ServiceRegistry serviceRegistry; ????static { ???????try { ???????????configuration.configure(); ???????????serviceRegistry = new StandardServiceRegistryBuilder().configure().build(); ???????????try { ???????????????sessionFactory = new MetadataSources(serviceRegistry).buildMetadata().buildSessionFactory(); ???????????} catch (Exception e) { ???????????????StandardServiceRegistryBuilder.destroy(serviceRegistry); ???????????????e.printStackTrace(); ???????????} ???????} catch (Exception e) { ???????????System.err.println("%%%% Error Creating SessionFactory %%%%"); ???????????e.printStackTrace(); ???????} ???} ???private HibernateSessionFactory() { ???} ???????/** ????* Returns the ThreadLocal Session instance. ?Lazy initialize ????* the <code>SessionFactory</code> if needed. ????* ????* ?@return Session ????* ?@throws HibernateException ????*/ ???public static Session getSession() throws HibernateException { ???????Session session = (Session) threadLocal.get(); ???????if (session == null || !session.isOpen()) { ???????????if (sessionFactory == null) { ???????????????rebuildSessionFactory(); ???????????} ???????????session = (sessionFactory != null) ? sessionFactory.openSession() ???????????????????: null; ???????????threadLocal.set(session); ???????} ???????return session; ???} ???/** ????* ?Rebuild hibernate session factory ????* ????*/ ???public static void rebuildSessionFactory() { ???????try { ???????????configuration.configure(); ???????????serviceRegistry = new StandardServiceRegistryBuilder().configure().build(); ???????????try { ???????????????sessionFactory = new MetadataSources(serviceRegistry).buildMetadata().buildSessionFactory(); ???????????} catch (Exception e) { ???????????????StandardServiceRegistryBuilder.destroy(serviceRegistry); ???????????????e.printStackTrace(); ???????????} ???????} catch (Exception e) { ???????????System.err.println("%%%% Error Creating SessionFactory %%%%"); ???????????e.printStackTrace(); ???????} ???} ???/** ????* ?Close the single hibernate session instance. ????* ????* ?@throws HibernateException ????*/ ???public static void closeSession() throws HibernateException { ???????Session session = (Session) threadLocal.get(); ???????threadLocal.set(null); ???????if (session != null) { ???????????session.close(); ???????} ???} ???/** ????* ?return session factory ????* ????*/ ???public static org.hibernate.SessionFactory getSessionFactory() { ???????return sessionFactory; ???} ???/** ????* ?return hibernate configuration ????* ????*/ ???public static Configuration getConfiguration() { ???????return configuration; ???}}测试类Test.java
package com.cn.test;import javax.persistence.Entity;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.AnnotationConfiguration;import org.hibernate.cfg.Configuration;import com.cn.pojo.Comment;import com.cn.pojo.News;@Entitypublic class Test { ???@org.junit.Test ???public void test1(){ ???????Configuration configuration = new AnnotationConfiguration().configure(); ???????SessionFactory sessionFactory = configuration.buildSessionFactory(); ???????Session session = sessionFactory.openSession(); ???????Transaction tx = session.beginTransaction(); ???????try { ???????????News news = new News("鍐滆锤鏍囬","鍐滆锤鍐呭"); ???????????Comment comment1 = new Comment("璇勮1銆傘?傘??"); ???????????Comment comment2 = new Comment("璇勮2銆傘?傘??"); ???????????comment1.setNews(news); ???????????comment2.setNews(news); ???????????session.save(comment1); ???????????session.save(comment2); ???????????tx.commit(); ???????} catch (Exception e) { ???????????tx.rollback(); ???????????e.printStackTrace(); ???????}finally{ ???????????session.close(); ???????????} ???}}检索：HQL
@org.junit.Test ???public void test1(){ ???????Configuration configuration = new AnnotationConfiguration().configure(); ???????SessionFactory sessionFactory = configuration.buildSessionFactory(); ???????//获取session对象 ???????Session session = sessionFactory.openSession(); ???????????????Transaction transaction = session.beginTransaction(); ???????????????try { ???????????//编写hql语句 ???????????String hql = "from Customer c where c.name=? and c.password=?"; ???????????//获取query对象 ???????????Query query = session.createQuery(hql).setString(0, "xxx").setString(1, "123456"); ???????????//动态绑定参数 ???????????/*query.setString(0, "xxx"); ???????????query.setString(1, "123456");*/ ???????????//操作query ???????????List<Customer> customers = query.list(); ???????????????????????for(Customer customer:customers){ ???????????????System.out.println("name="+customer.getName()); ???????????} ???????????????????????transaction.commit(); ???????} catch (Exception e) { ???????????e.printStackTrace(); ???????????transaction.rollback(); ???????} finally{ ???????????session.close(); ???????} ???????????}QBC
???@org.junit.Test ???public void test7(){ ???????Configuration configuration = new AnnotationConfiguration().configure(); ???????SessionFactory sessionFactory = configuration.buildSessionFactory(); ???????//获取session对象 ???????Session session = sessionFactory.openSession(); ???????????????Transaction transaction = session.beginTransaction(); ???????????????try { ???????????//select * from tb_customer ???????????Criteria criteria = session.createCriteria(Customer.class).add(Restrictions.like("name", "%杰")).add(Restrictions.eq("password", "123456")); ???????????????????????//创建条件 ???????????//name like "%杰" ???????????//password = "123456" ???????????//Criterion c1 = Restrictions.like("name", "%杰"); ???????????//Criterion c2 = Restrictions.eq("password", "123456"); ???????????????????????//将条件添加到sql语句里 ???????????//criteria.add(c1); ???????????//criteria.add(c2); ???????????????????????List<Customer> customers = criteria.list(); ???????????for(Customer customer:customers){ ???????????????System.out.println("name="+customer.getName()); ???????????} ???????????????????????transaction.commit(); ???????} catch (Exception e) { ???????????e.printStackTrace(); ???????????transaction.rollback(); ???????} finally{ ???????????session.close(); ???????} ???????????}Hibernate的注解和检索
原文地址：http://www.cnblogs.com/Vito-Yan/p/7758203.html