<!--hibernate核心依賴-->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>5.4.1.Final</version>
        </dependency>
        <!--    導(dǎo)入MySQL的依賴-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.26</version>
        </dependency>

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <!--配置所使用的Hibernate方言-->
        <property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>
        <property name="hibernate.connection.driver_class">com.mysql.cj.jdbc.Driver</property>
        <!-- Hibernate 連接數(shù)據(jù)庫的基本信息 -->
        <property name="connection.username">數(shù)據(jù)庫用戶名</property>
        <property name="connection.password">數(shù)據(jù)庫密碼</property>
        <property name="connection.driver_class">com.mysql.cj.jdbc.Driver</property>
        <property name="connection.url">數(shù)據(jù)庫連接地址</property>
        <!-- Hibernate 的基本配置 -->
        <!-- Hibernate 使用的數(shù)據(jù)庫方言 -->
        <property name="dialect">org.hibernate.dialect.MySQLInnoDBDialect</property>
        <!-- 運行時是否打印 SQL -->
        <!--        <property name="show_sql">true</property>-->
        <property name="hibernate.show_sql">true</property>
        <!-- 運行時是否格式化 SQL -->
        <!--        <property name="format_sql">true</property>-->
        <property name="hibernate.format_sql">true</property>
        <!-- 生成數(shù)據(jù)表的策略 -->
        <!-- <property name="hbm2ddl.auto">update</property>-->
        <!-- 加載Hibernate時，驗證數(shù)據(jù)庫表結(jié)構(gòu)與Hibernate映射的結(jié)構(gòu)是否匹配。如果不匹配，會拋出異常-->
        <property name="hbm2ddl.auto">validate</property>
        <!-- 設(shè)置 Hibernate 的事務(wù)隔離級別 -->
        <property name="connection.isolation">2</property>
        <!-- 刪除對象后, 使其 OID 置為 null -->
        <property name="use_identifier_rollback">true</property>
        <!-- 配置 C3P0 數(shù)據(jù)源 -->
        <property name="hibernate.c3p0.max_size">10</property>
        <property name="hibernate.c3p0.min_size">5</property>
        <property name="c3p0.acquire_increment">2</property>
        <property name="c3p0.idle_test_period">2000</property>
        <property name="c3p0.timeout">2000</property>
        <property name="c3p0.max_statements">10</property>
        <!-- 設(shè)定 JDBC 的 Statement 讀取數(shù)據(jù)的時候每次從數(shù)據(jù)庫中取出的記錄條數(shù) -->
        <property name="hibernate.jdbc.fetch_size">100</property>
        <!-- 設(shè)定對數(shù)據(jù)庫進行批量刪除，批量更新和批量插入的時候的批次大小 -->
        <property name="jdbc.batch_size">30</property>
        <!-- 需要關(guān)聯(lián)的 hibernate 映射文件 .hbm.xml，使用hbm.xml的時候使用 -->
        <!-- 掃描com.cx.bank.ORM包以查找?guī)ё⒔獾膶嶓w類 -->
        <mapping class="數(shù)據(jù)庫對應(yīng)實體類的路徑"/>
    </session-factory>
</hibernate-configuration>

<hibernate-mapping>
    <class name="com.hibernate.User">實體類映射成表 表名默認為User
        <id name="id">映射表的主鍵為實體的id屬性
            <generator class="uuid"/>主鍵按uuid方式生成
        </id>
        <property name="name"/>實體的其它屬性映射表的一般字段
        <property name="password"/>
        <property name="createTime"/>
        <property name="expireTime"/>
    </class>
</hibernate-mapping>

 public String findByName(String userName) {
        Session session = HibernateUtil.openSession();
        try {
            String hql = "from User where userName = :name";
            User user = session.createQuery(hql, User.class).setParameter("name", userName).uniqueResult();
            if (user != null) {
                return user.getUserName();
            } else {
                return null;
            }
        } finally {
            // 確保session被關(guān)閉
            if (session != null && session.isOpen()) {
                session.close();
            }
        }
    }

 @Test
    public void findByName() {
        System.out.println(FileDao.findByName("jj"));
    }

public class HibernateUtil {
    private static final SessionFactory sessionFactory = buildSessionFactory();
    private static SessionFactory buildSessionFactory() {
        try {
            // 使用hibernate.cfg.xml創(chuàng)建SessionFactory
            StandardServiceRegistry standardRegistry = new StandardServiceRegistryBuilder().configure("hibernate.cfg.xml").build();
            Metadata metadata = new MetadataSources(standardRegistry).getMetadataBuilder().build();
            return metadata.getSessionFactoryBuilder().build();
        } catch (Exception e) {
            e.printStackTrace();
            throw new RuntimeException("SessionFactory creation failed!");
        }
    }
    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }
    public static Session openSession() {
        return sessionFactory.openSession();
    }
    public static void closeSession(Session session) {
        if (session != null && session.isOpen()) {
            session.close();
        }
    }
}