《Hibernate上课笔记》----class2

一：使用Hibernate对数据库进行增删改查操作

准备环境 eclipse+mysql5.3+hibernate5.3

Hibernate配置文件

<?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">
<hibernate-configuration>
 <session-factory>
  <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
  <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
  <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hibernate?useUnicode=true&amp;characterEncoding=UTF-8</property>
  <property name="hibernate.connection.username">root</property>
  <property name="hibernate.connection.password"></property>
  <property name="hibernate.show_sql">true</property>
  <property name="hibernate.format_sql">true</property>
  <mapping resource="com/hibernate/entity/User.hbm.xml"/>
</session-factory>
</hibernate-configuration>

Hibernate工具类

public class HibernateUtil {
      private static SessionFactory factory;
      private  static StandardServiceRegistry registry;
     //得到sessionFactory
      static {
    	  try {
    		  //1.获取注册的register
        	  registry=new StandardServiceRegistryBuilder().configure().build();
             //2.得到factory
        	 factory =new MetadataSources(registry).buildMetadata().buildSessionFactory();
    	  }catch(Exception e) {
    		  e.printStackTrace();
    		  StandardServiceRegistryBuilder.destroy(registry);    		  
    	  }
    	
      }
      //获得session对象
      public static Session openSession() {
    	  return factory.openSession();
      }
      //关闭sessionFactory
      public static void closeFactory() {
    	  factory.close();
      }
      
}

用户实体类：

package com.hibernate.entity;

public class User {
	private Integer id;
	private String userName;
	private String passWord;
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getUserName() {
		return userName;
	}
	public void setUserName(String userName) {
		this.userName = userName;
	}
	public String getPassWord() {
		return passWord;
	}
	public void setPassWord(String passWord) {
		this.passWord = passWord;
	}
	@Override
	public String toString() {
		return "User [id=" + id + ", userName=" + userName + ", passWord=" + passWord + "]";
	}
	

}

用户配置文件：

<?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="com.hibernate.entity">
    <class name="User" table="t_user">
        <id name="id" type="int" >
           <column name="id"></column>
           <generator class="native"></generator>
        </id>
        <property name="userName" column="user_name" type="java.lang.String">
        </property>
       <property name="passWord" type="java.lang.String"></property>      
    </class>
</hibernate-mapping>

1.Hibernate增加操作

//持久化操作
	public static void saveUser(User user) {
		Transaction tx = null;
		Session session = null;
		try {
			
			//1.获得session对象
		    session=HibernateUtil.openSession();
			//2.获得要保存的实体对象
			//3.保存实体
			 tx=session.beginTransaction();
			session.save(user);
			tx.commit();
			//4.关闭session
		}catch(Exception e) {
			tx.rollback();
		}finally {
			session.close();
		}
		
	}

2.Hibernate查询操作

	public static User getUserById(int id) {
		Session session = null;
		User user = null;
		try {
			//1.获取session
			session=HibernateUtil.openSession();
			//2.去查询
			 user=session.get(User.class, id);//Hibernate会包装成数据类型
			
			//3.关闭session
			session.close();
		}catch(Exception e) {
			e.printStackTrace();
		}finally {
			session.close();
		}
		return user;
		
	}

3.Hibernate修改操作

public static void updateUser(User user) {
		//先查询出用户然后再更新
		Session session = null;
		Transaction tx=null;
		try {
			
			//1.先获取session对象
			session=HibernateUtil.openSession();
			//2.对数据进行更改
			tx=session.beginTransaction();
			user.setPassWord("456");
			//3.进行保存更新操作
			session.update(user);
			tx.commit();
			
		}catch(Exception e){
			e.printStackTrace();
			tx.rollback();
		}finally {
			//4.session关闭
			session.close();
		}
		
	}

4.Hibernate删除操作

public static void deleteUser(User user) {
		//先查询到对象后再删除
		//1.打开session
		//2.删除用户
		//3.关闭session
	
				Session session = null;
				Transaction tx=null;
				try {
					
					//1.先获取session对象
					session=HibernateUtil.openSession();
					//2.对数据进行更改
					tx=session.beginTransaction();			
					
					session.delete(user);
					tx.commit();
					
				}catch(Exception e){
					e.printStackTrace();
					tx.rollback();
				}finally {
					//4.session关闭
					session.close();
				}
				
	}
}