简单的Hibernate实例
1.编写POJO/javabean/domain类
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public class Employee implements Serializable{private static final long serialVersionUID = 1L;private Integer id;private String name;private String email;private java.util.Date hiredate;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getEmail() {return email;}public void setEmail(String email) {this.email = email;}public java.util.Date getHiredate() {return hiredate;}public void setHiredate(java.util.Date hiredate) {this.hiredate = hiredate;}}?2.编写mapping文件
<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE hibernate-mapping PUBLIC"-//Hibernate/Hibernate Mapping DTD 3.0//EN""http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"><hibernate-mapping package="POJO"><!-- name : 表示类名 table 表示该类和哪个表映射 --><class name="Employee" table="employee"><!-- id元素专门用于指定主键是如何生成,hibernate设计者认为，我们每一个表都应该有一个主键 --><!-- name:表示类的哪个属性是主键 --><id name="id" type="java.lang.Integer"><!-- 指定主键生成策略 --><generator type="java.lang.String"><column name="name" not-null="true" /></property><property name="email" type="java.lang.String"><column name="email" not-null="true" /></property><property name="hiredate" type="java.util.Date"><column name="hiredate" not-null="true" /></property></class></hibernate-mapping>?
?3.配置Hibernate.cfg.xml
设置自动创建数据库表，选择对应的数据库方言
<?xml version="1.0" encoding="UTF-8"?><!-- 指定Hibernate配置文件的DTD信息 --><!DOCTYPE hibernate-configuration PUBLIC"-//Hibernate/Hibernate Configuration DTD 3.0//EN""http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"><!-- hibernate- configuration是连接配置文件的根元素 --><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，hibernate连接的数据库名 --><property name="connection.url">jdbc:mysql://localhost:3306/jk</property><!-- 指定连接数据库的用户名 --><property name="connection.username">root</property><!-- 指定连接数据库的密码 --><property name="connection.password">root</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.MySQLInnoDBDialect</property><!-- 根据需要自动创建数据表 --><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><!-- 罗列所有的映射文件 --><mapping resource="POJO/Employee.hbm.xml"/></session-factory></hibernate-configuration>?
?4.编写测试类来操作Hibernate，简单的增删改操作！
修改和删除操作需要获得对象对应的ID
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import org.hibernate.Transaction;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.cfg.Configuration;import POJO.Employee;public class Test {public static void main(String[] args){//add();//delete();//update();//select("jk");search("k");}private static void update() {Configuration con = new Configuration().configure();SessionFactory sf = con.buildSessionFactory();Session session = sf.openSession();Transaction trans = session.beginTransaction();Employee emp = new Employee();emp = (Employee) session.load(emp.getClass(), 1);emp.setEmail("jk@12@12.com");session.update(emp);trans.commit();session.close();sf.close();}public static void add(){Configuration con = new Configuration().configure();SessionFactory sf = con.buildSessionFactory();Session session = sf.openSession();Transaction trans = session.beginTransaction();Employee emp = new Employee();emp.setName("jk");emp.setEmail("123@123.123");emp.setHiredate(new java.util.Date());session.save(emp);trans.commit();session.close();sf.close();}public static void delete(){Configuration con = new Configuration().configure();SessionFactory sf = con.buildSessionFactory();Session session = sf.openSession();Transaction trans = session.beginTransaction();Employee emp = new Employee();emp = (Employee) session.load(emp.getClass(), 3);session.delete(emp);trans.commit();session.close();sf.close();}public static void select(String name){Configuration config = new Configuration().configure();SessionFactory sf = config.buildSessionFactory();Session session = sf.openSession();Transaction trans = session.beginTransaction();Employee emp = null;String hql = "from Employee where name=:name";Query query = session.createQuery(hql);query.setParameter("name", name);List list = query.list();for(int i=0; i<list.size(); i++){Employee e = (Employee) list.get(i);System.out.println(e.getId());}}public static void search(String name){Configuration config = new Configuration().configure();SessionFactory sf = config.buildSessionFactory();Session session = sf.openSession();Transaction trans = session.beginTransaction();Employee emp = null;List list = session.createCriteria(Employee.class).add(Restrictions.like("name", "%"+name)).addOrder(Order.asc("id")).list();for(int i=0; i<list.size(); i++){emp = (Employee) list.get(i);System.out.println(emp.getName());}}}??
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