hibernate入门.docx

大致课程安排Hibernateday01 、hibernate人门（hibernate操作数据 查询、新增、删除、修改）1回顾：jdbc操作数据库1创建表person id 主键name 姓名age 年龄status 是否删除状态 0表示有效，1表示已删除状态2创建web项目3创建实体类(pojo、Entity)Person类int idString nameint ageString statuspackage com.chinasofti.pojo;import java.io.Serializable;SuppressWarnings(serial)public class Person implements Serializable private Integer id;private String name;private int age;private String status;public Person()public Person(String name, int age, String status) super(); = name;this.age = age;this.status = status;public Integer getId() return id;public void setId(Integer id) this.id = id;public String getName() return name;public void setName(String name) = name;public int getAge() return age;public void setAge(int age) this.age = age;public String getStatus() return status;public void setStatus(String status) this.status = status;4写获得Connection的JdbcUtil类package com.chinasofti.util;import java.io.IOException;import java.io.InputStream;import java.sql.Connection;import java.sql.DriverManager;import java.sql.SQLException;import java.util.Properties;public class JdbcUtil private static String driver;private static String url;private static String username;private static String password;private static ThreadLocal tlc = new ThreadLocal();/静态代码块staticProperties prop = new Properties();/perties 文件与JdbcUtil在同一目录下InputStream inStream = JdbcUtil.class.getResourceAsStream(perties);try prop.load(inStream);driver = prop.getProperty(driver);url = prop.getProperty(url);username = prop.getProperty(user);password = prop.getProperty(password); catch (IOException e) e.printStackTrace();public static Connection getConnection()/从ThreadLocal对象中获得与当前线程绑定的连接Connection con = tlc.get();if(con=null)try /加载mysql驱动包Class.forName(driver);/获得一个新的数据库的连接con = DriverManager.getConnection(url, username, password); catch (Exception e) e.printStackTrace();return con;public static void closeConnection(Connection con)if(con!=null)try con.close(); catch (SQLException e) e.printStackTrace();5创建Dao类 Dao是用来操作数据库数据的对象package com.chinasofti.dao;import java.sql.Connection;import java.sql.PreparedStatement;import java.sql.ResultSet;import java.sql.SQLException;import java.util.ArrayList;import java.util.List;import com.chinasofti.pojo.Person;import com.chinasofti.util.JdbcUtil;public class PersonDao public List findPersons()List persons = new ArrayList();/获得数据库连接Connection con = JdbcUtil.getConnection();/创建预编译Sql语句，防止SQL注入String sql = select * from tbl_person;try PreparedStatement prs = con.prepareStatement(sql);/执行sql语句，查询数据库ResultSet rs = prs.executeQuery();/把从数据库中查询到的数据封装到Person对象中Person p = null;while(rs.next()p = new Person();p.setId(rs.getInt(id);p.setName(rs.getString(name);p.setAge(rs.getInt(age);p.setStatus(rs.getString(status);persons.add(p); catch (SQLException e) e.printStackTrace();return persons;5创建测试类TestJdbc类,测试连接是否成功获取package com.chinasofti.test;import java.sql.Connection;import java.util.List;import org.junit.Test;import com.chinasofti.dao.PersonDao;import com.chinasofti.pojo.Person;import com.chinasofti.util.JdbcUtil;public class TestJdbc Testpublic void test1()Connection con = JdbcUtil.getConnection();System.out.println(con);Testpublic void test2()PersonDao dao = new PersonDao();List ps = dao.findPersons();for(Person p:ps)System.out.println(p.getId()+,+p.getName();2hibernate:orm关联关系映射框架1创建web项目2导入hibernate的jar包3配置hibernate.cfg.xml主配置文件4创建实体类与实体类映射文件Person.hbm.xmlcom.mysql.jdbc.Driverrootrootorg.hibernate.dialect.MySQL5Dialecttruefalsethread5创建HibernateUtil类，获得Hibernate中的Sessionpackage com.chinasofti.util;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.cfg.Configuration;public class HibernateUtil private static SessionFactory sessionFactory;static/加载hibernate主配置文件Configuration cfg = new Configuration();cfg.configure(hibernate.cfg.xml);/创建hibernate的session工厂sessionFactory = cfg.buildSessionFactory();public static Session getHibernateSession()/获得与当前线程绑定的hibernate的session/*thread*/Session session = sessionFactory.getCurrentSession();return session;public void closeHibernateSession(Session session)if(session!=null)session.close();6创建实体类及实体类映射文件package com.chinasofti.pojo;import java.io.Serializable;SuppressWarnings(serial)public class Person implements Serializable private Integer id;private String name;private int age;private String status;public Person()public Person(String name, int age, String status) super(); = name;this.age = age;this.status = status;public Integer getId() return id;public void setId(Integer id) this.id = id;public String getName() return name;public void setName(String name) = name;public int getAge() return age;public void setAge(int age) this.age = age;public String getStatus() return status;public void setStatus(String status) this.status = status;Person.hbm.xml文件内容7创建测试类:package com.chinasofti.test;import java.util.List;import org.hibernate.Session;import org.hibernate.Transaction;import org.junit.Test;import com.chinasofti.dao.PersonDao;import com.chinasofti.pojo.Person;import com.chinasofti.util.HibernateUtil;public class HibernateTest Testpublic void test1()Session session = HibernateUtil.getHibernateSession();System.out.println(session);Testpublic void test2()PersonDao dao = new PersonDao();List ps = dao.findPersons();for(Person p:ps)System.out.println(p.getId()+,+p.getName()+,+p.getStatus();/* * Session: * servlet中的Session是一次会话，就是指浏览器与服务器之间的通信 * Hibernate的Session是一个连接,就是指我们的应用程序与数据库之间的一个连接 * * 通过主键id获得数据库数据 * get()当id对应的数据不存在的时候返回null * load()当id对应的数据不存在的时候抛出异常 * org.hibernate.OjbectNotFoundException: * No row with the given identifier exists * * 延迟加载的问题： * * 修改和新增: */Testpublic void test3()/获得hibernate的连接Session session = HibernateUtil.getHibernateSession();/开启事务Transaction tx = session.beginTransaction();/执行查询/get()立刻加载 Person p = (Person) session.get(Person.class,1);/延迟加载/Person p = (Person) session.load(Person.class,1);System.out.println(p);/提交事务mit();if(p!=null)System.out.println(p.getId()+,+p.getName();Hibernate: select person0_.id as id0_,person0_.name as name0_, person0_.age as age0_, person0_.status as status0_ from test.tbl_person person0_ where person0_.status=0对象Seesion理解：Session分两种：Servlet中的Session和Hibernate中的Session有什么区别？Servlet中的Session是指浏览器访问服务器的时候，在服务器中创建的浏览器与服务器之间的一个会话。默认浏览器关