第二次作业 单例模式的SessionFactory

Posted 2020-11-04 sangewuxie

一、基础Hibernate环境搭建（参见http://www.cnblogs.com/sangewuxie/p/9004968.html）

二、实体类User及User.hbm.xml配置

1.User类

package com.domain;

public class User {
	private Integer id;
	private String username;
	private String password;
	private Integer age;
	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;
	}
	public Integer getAge() {
		return age;
	}
	public void setAge(Integer age) {
		this.age = age;
	}
	@Override
	public String toString() {
		return "User [id=" + id + ", username=" + username + ", password=" + password + ", age=" + age + "]";
	}
	
}

2.User.hbm.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
	<!-- name: 完整类名    table:数据库表名 -->
	<class name="com.domain.User" table="user">
		<!-- id配置表的主键  name代表表中属性 -->
		<id name="id" column="id">
			<!-- 主键生成策略 -->
			<generator class="native"></generator>
		</id>
		<property name="username" column="username" type="string"></property>
		<property name="password" column="password" type="string"></property>
		<property name="age" column="age" type="integer"></property>
	</class>
</hibernate-mapping>

三、hibernate.cfg.xml

<?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>
            <!-- 指定方言 -->
            <property name="hibernate.dialect">org.hibernate.dialect.mysqlDialect</property>
             <!-- 数据库驱动 -->
            <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
             <!-- 数据库url -->
            <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hibernate02_1514010311</property>
             <!-- 数据库连接用户名 -->
            <property name="hibernate.connection.username">root</property>
             <!-- 数据库连接密码 -->
            <property name="hibernate.connection.password">0x3137</property>
            <!-- 将hibernate生成的sql语句打印到控制台 -->
            <property name="hibernate.show_sql">true</property>
            <!-- 将hibernate生成的sql语句格式化(语法缩进) -->
            <property name="hibernate.format_sql">true</property>
            <mapping resource="com/domain/User.hbm.xml" />
        </session-factory>
        
        
    </hibernate-configuration>

四、HibernateUtil

在这个工具类中写一个通过静态代码块生成唯一的SessionFactory，通过一个方法返回一个SessionFactory

package com.util;

import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;

public class HibernateUtil {
    private static Configuration cfg;
    private static SessionFactory sessionFactory;
    static {
        try {
            cfg = new Configuration().configure();
            sessionFactory = cfg.buildSessionFactory();
        }catch (Exception e) {
            e.printStackTrace();
        }
    }
    
    
    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }
}

五、测试类TestUser

package com.test;


import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.junit.Test;

import com.domain.User;
import com.util.HibernateUtil;

public class TestUser {
    @Test
    public void saveUser() {
        SessionFactory sessionFactory = null;
        Session session = null;
        Transaction transaction = null;
        User user = new User();
        user.setUsername("三哥无邪");
        user.setPassword("1514010311");
        user.setAge(21);
        try {
            sessionFactory = HibernateUtil.getSessionFactory();
            session = sessionFactory.openSession();
            transaction = session.beginTransaction();
            session.save(user);
            transaction.commit();
        } catch (Exception e) {
            if (transaction!=null) {
                transaction.rollback();
            }
            e.printStackTrace();
        }finally {
            if(session!=null) {
                session.close();
            }
        }
    }
    
    @Test
    public void updateUser() {
        
        SessionFactory sessionFactory = null;
        Session session = null;
        Transaction transaction = null;
        try {
            sessionFactory = HibernateUtil.getSessionFactory();
            session = sessionFactory.openSession();
            transaction = session.beginTransaction();
            User user = session.get(User.class, 1);
            user.setUsername("三哥无邪啊");
            user.setPassword("1514010311");
            user.setAge(21);
            session.update(user);
            transaction.commit();
        } catch (Exception e) {
            if (transaction!=null) {
                transaction.rollback();
            }
            e.printStackTrace();
        }finally {
            if(session!=null) {
                session.close();
            }
        }
    }
    
    @Test
    public void queryUser() {
        
        SessionFactory sessionFactory = null;
        Session session = null;
        Transaction transaction = null;
        try {
            sessionFactory = HibernateUtil.getSessionFactory();
            session = sessionFactory.openSession();
            transaction = session.beginTransaction();
            User user = session.get(User.class, 2);
            System.out.println("ID:"+user.getId()+" 用户名："+user.getUsername()+" 密码："+user.getPassword());
            transaction.commit();
        } catch (Exception e) {
            if (transaction!=null) {
                transaction.rollback();
            }
            e.printStackTrace();
        }finally {
            if(session!=null) {
                session.close();
            }
        }
    }
    @Test
    public void deleteUser() {
        
        SessionFactory sessionFactory = null;
        Session session = null;
        Transaction transaction = null;
        try {
            sessionFactory = HibernateUtil.getSessionFactory();
            session = sessionFactory.openSession();
            transaction = session.beginTransaction();
            User user = session.get(User.class, 1);
            session.delete(user);
            transaction.commit();
        } catch (Exception e) {
            if (transaction!=null) {
                transaction.rollback();
            }
            e.printStackTrace();
        }
    }
}

测试一次saveUser方法，结果如图

 

就此获取单例模式的SessionFactory的方式就完成了