hibernate单独使用参考示例

<?xml version="1.0" encoding="GBK"?><!-- 指定Hibernate配置文件的DTD信息 --> ?<!DOCTYPE hibernate-configuration PUBLIC ?<span style="white-space:pre;"></span>"-//Hibernate/Hibernate Configuration DTD 3.0//EN"<span style="white-space:pre;"></span>"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"><!-- hibernate-configuration是配置文件的根元素 --><hibernate-configuration> ??<session-factory> ?????<!-- 指定连接数据库所用的驱动 --> ?????<property name="connection.driver_class">com.mysql.jdbc.Driver</property> ?????<!-- 指定连接数据库的url，其中hibernate是本应用连接的数据库名 --> ?????<property name="connection.url">jdbc:mysql://localhost/hibernate</property> ?????<!-- 指定连接数据库的用户名 --> ?????<property name="connection.username">test</property> ?????<!-- 指定连接数据库的密码 --> ?????<property name="connection.password">******</property> ?????<!-- 指定连接池里最大连接数 --> ?????<property name="hibernate.c3p0.max_size">20</property> ?????<!-- 指定连接池里最小连接数 --> ?????<property name="hibernate.c3p0.min_size">1</property> ?????<!-- 指定连接池里连接的超时时长 --> ?????<property name="hibernate.c3p0.timeout">5000</property> ?????<!-- 指定连接池里最大缓存多少个Statement对象 --> ?????<property name="hibernate.c3p0.max_statements">100</property> ?????<property name="hibernate.c3p0.idle_test_period">3000</property> ?????<property name="hibernate.c3p0.acquire_increment">2</property> ?????<property name="hibernate.c3p0.validate">true</property> ?????<!-- 指定数据库方言 --> ?????<property name="dialect">org.hibernate.dialect.MySQLDialect</property> ?????<!-- 根据需要自动创建数据库 --> ?????<property name="hbm2ddl.auto">update</property> ?????<!-- 显示Hibernate持久化操作所生成的SQL --> ?????<property name="show_sql">true</property> ?????<!-- 将SQL脚本进行格式化后再输出 --> ?????<property name="hibernate.format_sql">true</property> ?????<!-- 罗列所有持久化类的类名 --> ?????<mapping class="hibernate.test.EntityA" /> ?????<mapping class="hibernate.test.EntityB" /> ??</session-factory></hibernate-configuration>

public class HibernateUtil { ???public static final SessionFactory sessionFactory; ???static { ???????try { ???????????// 使用默认的hibernate.cfg.xml配置文件创建Configuration实例 ???????????Configuration cfg = new Configuration().configure(); ???????????// 以Configuration实例来创建SessionFactory实例 ???????????ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(cfg.getProperties()) ???????????????????.build(); ???????????sessionFactory = cfg.buildSessionFactory(serviceRegistry); ???????} catch (Throwable ex) { ???????????System.err.println("Initial SessionFactory creation failed." + ex); ???????????throw new ExceptionInInitializerError(ex); ???????} ???} ???// ThreadLocal可以隔离多个线程的数据共享，因此不再需要对线程同步 ???public static final ThreadLocal<Session> session = new ThreadLocal<Session>(); ???public static Session currentSession() throws HibernateException { ???????Session s = session.get(); ???????// 如果该线程还没有Session,则创建一个新的Session ???????if (s == null) { ???????????s = sessionFactory.openSession(); ???????????// 将获得的Session变量存储在ThreadLocal变量session里 ???????????session.set(s); ???????} ???????return s; ???} ???public static void closeSession() throws HibernateException { ???????Session s = session.get(); ???????if (s != null) { ???????????s.close(); ???????} ???????session.set(null); ???}}

package hibernate.test; ?????import java.io.Serializable; ?import java.util.HashSet; ?import java.util.Set; ?????import javax.persistence.Entity; ?import javax.persistence.GeneratedValue; ?import javax.persistence.GenerationType; ?import javax.persistence.Id; ?import javax.persistence.OneToMany; ?????@Entity ?public class EntityA implements Serializable { ?????@Id ?????@GeneratedValue(strategy = GenerationType.AUTO) ?????private Integer ida; ?????private String columnOne; ?????private String columnTwo; ?????????@OneToMany(targetEntity = EntityB.class, mappedBy = "ea") ?????private Set<EntityB> ebs = new HashSet<EntityB>(); ?????????public EntityA() { ?????????} ?????????public EntityA(String columnOne, String columnTwo) { ?????????this.columnOne = columnOne; ?????????this.columnTwo = columnTwo; ?????} ?????????public Integer getIda() { ?????????return ida; ?????} ?????????public void setIda(Integer ida) { ?????????this.ida = ida; ?????} ?????????public String getColumnOne() { ?????????return columnOne; ?????} ?????????public void setColumnOne(String columnOne) { ?????????this.columnOne = columnOne; ?????} ?????????public String getColumnTwo() { ?????????return columnTwo; ?????} ?????????public void setColumnTwo(String columnTwo) { ?????????this.columnTwo = columnTwo; ?????} ?????????public Set<EntityB> getEbs() { ?????????return ebs; ?????} ?????????public void setEbs(Set<EntityB> ebs) { ?????????this.ebs = ebs; ?????} ?????} ?

package hibernate.test; ?????import java.io.Serializable; ?????import javax.persistence.Entity; ?import javax.persistence.GeneratedValue; ?import javax.persistence.GenerationType; ?import javax.persistence.Id; ?import javax.persistence.JoinColumn; ?import javax.persistence.ManyToOne; ?????@Entity ?public class EntityB implements Serializable { ?????@Id ?????@GeneratedValue(strategy = GenerationType.AUTO) ?????private Integer idb; ?????private String columnOne; ?????private String columnTwo; ?????@ManyToOne(targetEntity = EntityA.class) ?????@JoinColumn(name = "b_a", nullable = false) ?????private EntityA ea; ?????????public EntityB() { ?????????} ?????????public EntityB(String columnOne, String columnTwo) { ?????????this.columnOne = columnOne; ?????????this.columnTwo = columnTwo; ?????} ?????????public Integer getIdb() { ?????????return idb; ?????} ?????????public void setIdb(Integer idb) { ?????????this.idb = idb; ?????} ?????????public String getColumnOne() { ?????????return columnOne; ?????} ?????????public void setColumnOne(String columnOne) { ?????????this.columnOne = columnOne; ?????} ?????????public String getColumnTwo() { ?????????return columnTwo; ?????} ?????????public void setColumnTwo(String columnTwo) { ?????????this.columnTwo = columnTwo; ?????} ?????????public EntityA getEa() { ?????????return ea; ?????} ?????????public void setEa(EntityA ea) { ?????????this.ea = ea; ?????} ?????} ?