什么是hibernate
ORM框架/持久层框架 jdbc的一个框架
object reference mapping
通过管理对象来改变数据库中的数据
通过管理对象来操作数据库
hibernate的优势:跨数据库的无缝移植
如何在项目中添加hibernate支持(手动添加)
1.添加hibernate相关依赖
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.lww</groupId> <artifactId>T224_hibernate</artifactId> <packaging>war</packaging> <version>0.0.1-SNAPSHOT</version> <name>T224_hibernate Maven Webapp</name> <url>http://maven.apache.org</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>1.8</maven.compiler.source> <maven.compiler.target>1.8</maven.compiler.target> <junit.version>4.12</junit.version> <servlet.version>4.0.0</servlet.version> <hibernate.version>5.3.0.Final</hibernate.version> <mysql.driver.version>5.1.46</mysql.driver.version> </properties> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>${junit.version}</version> <scope>test</scope> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>javax.servlet-api</artifactId> <version>${servlet.version}</version> <scope>provided</scope> </dependency> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-core</artifactId> <version>${hibernate.version}</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>${mysql.driver.version}</version> </dependency> </dependencies> <build> <finalName>T224_hibernate</finalName> <plugins> <plugin> <groupId>org.apache.maven.plugins</groupId> <artifactId>maven-compiler-plugin</artifactId> <version>3.7.0</version> <configuration> <source>${maven.compiler.source}</source> <target>${maven.compiler.target}</target> <encoding>${project.build.sourceEncoding}</encoding> </configuration> </plugin> </plugins> </build> </project>
2.在resource目录下添加hibernate.cfg.xml(核心配置文件)
<?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> <!-- 1. 数据库相关 --> <property name="connection.username">root</property> <property name="connection.password">123</property> <property name="connection.url">jdbc:mysql://localhost:3306/t224?useUnicode=true&characterEncoding=UTF-8 </property> <property name="connection.driver_class">com.mysql.jdbc.Driver</property> <property name="dialect">org.hibernate.dialect.MySQLDialect</property> <!-- 配置本地事务(No CurrentSessionContext configured!) --> <property name="hibernate.current_session_context_class">thread</property> <!-- 2. 调试相关 --> <property name="show_sql">true</property> <property name="format_sql">true</property> <!-- 3. 添加实体映射文件 --> <mapping resource="com/liuwenwu/one/entity/User.hbm.xml" /> </session-factory> </hibernate-configuration>
3.建立实体类User
package com.liuwenwu.one.entity; import java.sql.Date; import java.sql.Timestamp; public class User { private Integer id; private String userName; private String userPwd; private String sex; private Date birthday; private String realName; private Timestamp createDatetime; private String remark; 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 getUserPwd() { return userPwd; } public void setUserPwd(String userPwd) { this.userPwd = userPwd; } public String getSex() { return sex; } public void setSex(String sex) { this.sex = sex; } public Date getBirthday() { return birthday; } public void setBirthday(Date birthday) { this.birthday = birthday; } public String getRealName() { return realName; } public void setRealName(String realName) { this.realName = realName; } public Timestamp getCreateDatetime() { return createDatetime; } public void setCreateDatetime(Timestamp createDatetime) { this.createDatetime = createDatetime; } public String getRemark() { return remark; } public void setRemark(String remark) { this.remark = remark; } public User() { super(); } public User(Integer id, String userName, String userPwd, String sex, Date birthday, String realName, Timestamp createDatetime, String remark) { super(); this.id = id; this.userName = userName; this.userPwd = userPwd; this.sex = sex; this.birthday = birthday; this.realName = realName; this.createDatetime = createDatetime; this.remark = remark; } @Override public String toString() { return "User [id=" + id + ", userName=" + userName + ", userPwd=" + userPwd + ", sex=" + sex + ", birthday=" + birthday + ", realName=" + realName + ", createDatetime=" + createDatetime + ", remark=" + remark + "]"; } }
4.实体类的配置文件 User.hbm.xml 映射实体类(User)
<?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> <!-- class标签: name:对应的是需要映射的实体类的全路径名 table:实体类对应的数据库中的表名 id标签: 配置的是表中的主键 name:对应的是实体类属性名 type:指的是实体类数据类型 column:数据库表对应的列名 property标签:配置除主键以为列段对应的类属性映射关系 name:对应的是实体类属性名 type:指的是实体类数据类型 column:数据库表对应的列名 insert="false" update="false" 表示该列段或者说该属性只做查询使用,不做更新(修改) --> <class name="com.liuwenwu.one.entity.User" table="t_hibernate_user"> <id name="id" type="java.lang.Integer" column="id"> <generator class="increment" /> </id> <property name="userName" type="java.lang.String" column="user_name"> </property> <property name="userPwd" type="java.lang.String" column="user_pwd"> </property> <property name="realName" type="java.lang.String" column="real_name"> </property> <property name="sex" type="java.lang.String" column="sex"> </property> <property name="birthday" type="java.sql.Date" column="birthday"> </property> <property insert="false" update="false" name="createDatetime" type="java.sql.Timestamp" column="create_datetime"> </property> <property name="remark" type="java.lang.String" column="remark"> </property> </class> </hibernate-mapping>
接下来是CRUD的演示
查询:
package com.liuwenwu.demo; import java.util.List; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration; /** * hibernate查询演示 * @author ASUS */ public class QueryDemo { public static void main(String[] args) { Configuration configure = new Configuration().configure("/hibernate.cfg.xml"); SessionFactory sessionFactory = configure.buildSessionFactory(); //会话 而这里的会话指的是操作数据库的链接 Session session = sessionFactory.openSession(); List list = session.createQuery("from User").list(); for (Object obj : list) { System.out.println(obj); } session.close(); } }
新增:
package com.liuwenwu.demo; import java.sql.Date; import java.sql.Timestamp; import java.util.List; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.Transaction; import org.hibernate.cfg.Configuration; import com.liuwenwu.one.entity.User; /** * hibernate新增演示 * @author ASUS * */ public class InsertDemo { public static void main(String[] args) { Configuration configure = new Configuration().configure("/hibernate.cfg.xml"); SessionFactory sessionFactory = configure.buildSessionFactory(); //会话 而这里的会话指的是操作数据库的链接 Session session = sessionFactory.openSession(); Transaction transaction = session.beginTransaction(); session.save(new User(null, "aa", "版本", "男", new Date(System.currentTimeMillis()), "存储", new Timestamp(System.currentTimeMillis()), "信息")); transaction.commit(); session.close(); } }
修改:
package com.liuwenwu.demo; import java.sql.Date; import java.sql.Timestamp; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.Transaction; import org.hibernate.cfg.Configuration; import com.liuwenwu.one.entity.User; /** * hibernate修改演示 * @author ASUS * */ public class UpdateDemo { public static void main(String[] args) { Configuration configure = new Configuration().configure("/hibernate.cfg.xml"); SessionFactory sessionFactory = configure.buildSessionFactory(); //会话 而这里的会话指的是操作数据库的链接 Session session = sessionFactory.openSession(); Transaction transaction = session.beginTransaction(); // session.save(new User(null, "aa", "版本", "男", new Date(System.currentTimeMillis()), "存储", new Timestamp(System.currentTimeMillis()), "信息")); // User u=new User(null, "aa", "版本", "男", new Date(System.currentTimeMillis()), "存储", new Timestamp(System.currentTimeMillis()), "信息"); // u.setRealName("啥"); User user = session.get(User.class, 2); user.setRealName("三毛"); transaction.commit(); session.close(); } }
删除:
package com.liuwenwu.demo; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.Transaction; import org.hibernate.cfg.Configuration; import com.liuwenwu.one.entity.User; /** * hibernate删除的演示 * @author ASUS * */ public class DeleteDemo { public static void main(String[] args) { Configuration configure = new Configuration().configure("/hibernate.cfg.xml"); SessionFactory sessionFactory = configure.buildSessionFactory(); //会话 而这里的会话指的是操作数据库的链接 Session session = sessionFactory.openSession(); Transaction transaction = session.beginTransaction(); User user = new User(); user.setId(2); session.delete(user); transaction.commit(); session.close(); } }
Hibernate的管理对象的三种状态运行图解
原文地址:https://www.cnblogs.com/xiatian3452/p/11273592.html
时间: 2024-10-28 00:34:34