/** * 客户管理的实体类 * @author jt *CREATE TABLE `cst_customer` ( `cust_id` bigint(32) NOT NULL AUTO_INCREMENT COMMENT '客户编号(主键)', `cust_name` varchar(32) NOT NULL COMMENT '客户名称(公司名称)', `cust_source` varchar(32) DEFAULT NULL COMMENT '客户信息来源', `cust_industry` varchar(32) DEFAULT NULL COMMENT '客户所属行业', `cust_level` varchar(32) DEFAULT NULL COMMENT '客户级别', `cust_phone` varchar(64) DEFAULT NULL COMMENT '固定电话', `cust_mobile` varchar(16) DEFAULT NULL COMMENT '移动电话', PRIMARY KEY (`cust_id`) ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8; */ public class Customer { private Long cust_id; private String cust_name; private String cust_source; private String cust_industry; private String cust_level; private String cust_phone; private String cust_mobile; public Long getCust_id() { return cust_id; } public void setCust_id(Long cust_id) { this.cust_id = cust_id; } public String getCust_name() { return cust_name; } public void setCust_name(String cust_name) { this.cust_name = cust_name; } public String getCust_source() { return cust_source; } public void setCust_source(String cust_source) { this.cust_source = cust_source; } public String getCust_industry() { return cust_industry; } public void setCust_industry(String cust_industry) { this.cust_industry = cust_industry; } public String getCust_level() { return cust_level; } public void setCust_level(String cust_level) { this.cust_level = cust_level; } public String getCust_phone() { return cust_phone; } public void setCust_phone(String cust_phone) { this.cust_phone = cust_phone; } public String getCust_mobile() { return cust_mobile; } public void setCust_mobile(String cust_mobile) { this.cust_mobile = cust_mobile; } @Override public String toString() { return "Customer [cust_id=" + cust_id + ", cust_name=" + cust_name + ", cust_source=" + cust_source + ", cust_industry=" + cust_industry + ", cust_level=" + cust_level + ", cust_phone=" + cust_phone + ", cust_mobile=" + cust_mobile + "]"; } }
<?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> <!-- 建立类与表的映射 --> <class name="com.itheima.hibernate.demo1.Customer" table="cst_customer"> <!-- 建立类中的属性与表中的主键对应 --> <id name="cust_id" column="cust_id" > <generator class="native"/> </id> <!-- 建立类中的普通的属性和表的字段的对应 --> <property name="cust_name" column="cust_name" length="32" /> <property name="cust_source" column="cust_source" length="32"/> <property name="cust_industry" column="cust_industry"/> <property name="cust_level" column="cust_level"/> <property name="cust_phone" column="cust_phone"/> <property name="cust_mobile" column="cust_mobile"/> </class> </hibernate-mapping>
打开window----preferences,输入xml 进入xml catalog 点击add按钮
然后将配置文件中的网络地址复制到key中,将keytype设置为URI,在点击file system 选择本地下载好的dtd文件即可
<?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> <!-- 连接数据库的基本参数 --> <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property> <property name="hibernate.connection.url">jdbc:mysql:///hibernate_day01</property> <property name="hibernate.connection.username">root</property> <property name="hibernate.connection.password">abc</property> <!-- 配置Hibernate的方言 --> <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property> <!-- 可选配置================ --> <!-- 打印SQL --> <property name="hibernate.show_sql">true</property> <!-- 格式化SQL --> <property name="hibernate.format_sql">true</property> <!-- 自动创建表 --> <property name="hibernate.hbm2ddl.auto">update</property> <!-- 配置C3P0连接池 --> <property name="connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property> <!--在连接池中可用的数据库连接的最少数目 --> <property name="c3p0.min_size">5</property> <!--在连接池中所有数据库连接的最大数目 --> <property name="c3p0.max_size">20</property> <!--设定数据库连接的过期时间,以秒为单位, 如果连接池中的某个数据库连接处于空闲状态的时间超过了timeout时间,就会从连接池中清除 --> <property name="c3p0.timeout">120</property> <!--每3000秒检查所有连接池中的空闲连接 以秒为单位--> <property name="c3p0.idle_test_period">3000</property> <mapping resource="com/itheima/hibernate/demo1/Customer.hbm.xml"/> </session-factory> </hibernate-configuration>
// 1.加载Hibernate的核心配置文件 Configuration configuration = new Configuration().configure(); // 手动加载映射 // configuration.addResource("com/itheima/hibernate/demo1/Customer.hbm.xml"); // 2.创建一个SessionFactory对象:类似于JDBC中连接池 SessionFactory sessionFactory = configuration.buildSessionFactory(); // 3.通过SessionFactory获取到Session对象:类似于JDBC中Connection Session session = sessionFactory.openSession(); // 4.手动开启事务: Transaction transaction = session.beginTransaction(); // 5.编写代码 Customer customer = new Customer(); customer.setCust_name("王西"); session.save(customer); // 6.事务提交 transaction.commit(); // 7.资源释放 session.close(); sessionFactory.close();
Configuration cfg = new Configuration();
Configuration cfg = new Configuration().configure();
// 手动加载映射
configuration.addResource("com/itheima/hibernate/demo1/Customer.hbm.xml"
SessionFactory内部维护了Hibernate的连接池和Hibernate的二级缓存(不讲)。是线程安全的对象。一个项目创建一个对象即可。
创建一个静态的sessionFactory,这样就可以控制一个项目只创建一个sessionFactory对象
/** * Hibernate的工具类 * @author jt * */ public class HibernateUtils { public static final Configuration cfg; public static final SessionFactory sf; static{ cfg = new Configuration().configure(); sf = cfg.buildSessionFactory(); } public static Session openSession(){ return sf.openSession(); } }
Session代表的是Hibernate与数据库的链接对象。不是线程安全的。与数据库交互桥梁。
Session session = HibernateUtils.openSession(); Transaction tx = session.beginTransaction(); /** * get方法 * * 采用的是立即加载,执行到这行代码的时候,就会马上发送SQL语句去查询。 * * 查询后返回是真实对象本身。 * * 查询一个找不到的对象的时候,返回null * * load方法 * * 采用的是延迟加载(lazy懒加载),执行到这行代码的时候,不会发送SQL语句,当真正使用这个对象的时候才会发送SQL语句。 * * 查询后返回的是代理对象。javassist-3.18.1-GA.jar 利用javassist技术产生的代理。 * * 查询一个找不到的对象的时候,返回ObjectNotFoundException */ // 使用get方法查询 /*Customer customer = session.get(Customer.class, 100l); // 发送SQL语句 System.out.println(customer);*/ // 使用load方法查询 Customer customer = session.load(Customer.class, 200l); System.out.println(customer); tx.commit(); session.close();
Session session = HibernateUtils.openSession(); Transaction tx = session.beginTransaction(); // 直接创建对象,进行修改 /*Customer customer = new Customer(); customer.setCust_id(1l); customer.setCust_name("王聪"); session.update(customer);*/ // 先查询,再修改(推荐) Customer customer = session.get(Customer.class, 1l); customer.setCust_name("王小贱"); session.update(customer); tx.commit(); session.close();
Session session = HibernateUtils.openSession(); Transaction tx = session.beginTransaction(); // 直接创建对象,删除 /* Customer customer = new Customer(); customer.setCust_id(1l); session.delete(customer);*/ // 先查询再删除(推荐)--级联删除 Customer customer = session.get(Customer.class, 2l); session.delete(customer); tx.commit(); session.close();
Session session = HibernateUtils.openSession(); Transaction tx = session.beginTransaction(); /*Customer customer = new Customer(); customer.setCust_name("王凤"); session.saveOrUpdate(customer);*/ Customer customer = new Customer(); customer.setCust_id(3l); customer.setCust_name("李如花"); session.saveOrUpdate(customer); tx.commit(); session.close();
查询所有
Session session = HibernateUtils.openSession(); Transaction tx = session.beginTransaction(); // 接收HQL:Hibernate Query Language 面向对象的查询语言 /*Query query = session.createQuery("from Customer"); List<Customer> list = query.list(); for (Customer customer : list) { System.out.println(customer); }*/ // 接收SQL: SQLQuery query = session.createSQLQuery("select * from cst_customer"); List<Object[]> list = query.list(); for (Object[] objects : list) { System.out.println(Arrays.toString(objects)); } tx.commit(); session.close();
Hibernate中管理事务的对象。