一. 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
mybatis
优势:跨数据库的无缝移植
进行一个hibernate增删改查的示例:
所需要的文件及类:
1.建立一个完整的Maven项目
2.配置pom.xml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.cjq.one</groupId>
<artifactId>cjq_hibernate</artifactId>
<packaging>war</packaging>
<version>0.0.1-SNAPSHOT</version>
<name>cjq_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>cjq_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>
3.配置核心文件 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>
<!-- 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/test?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/cjq/one/entity/User.hbm.xml" /> </session-factory>
</hibernate-configuration>
4.配置映射文件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>
<!-- class标签下的属性
name:指的是数据库中所有表格映射的类的全路径名
table:指的是要映射的数据库表
id标签,是用来标识主键的映射列
name:数据库的列段映射到实体类中的属性名
type:属性名的类型
column:数据库中的列段名
property标签:
name:数据库的列段映射到实体类中的属性名
type:属性名的类型
column:数据库中的列段名
-->
<class name="com.cjq.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>
5.创建映射实体类User.java:
package com.cjq.one.entity;
import java.sql.Date;
import java.sql.Timestamp;public class User { private Integer id;
private String userName;
private String userPwd;
private String realName;
private String sex;
private Date birthday;
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 getRealName() {
return realName;
} public void setRealName(String realName) {
this.realName = realName;
} 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 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(String userName, String userPwd, String realName, String sex, Date birthday, Timestamp createDatetime,
String remark) {
super();
this.userName = userName;
this.userPwd = userPwd;
this.realName = realName;
this.sex = sex;
this.birthday = birthday;
this.createDatetime = createDatetime;
this.remark = remark;
} public User() {
super();
} @Override
public String toString() {
return "User [id=" + id + ", userName=" + userName + ", userPwd=" + userPwd + ", realName=" + realName
+ ", sex=" + sex + ", birthday=" + birthday + ", createDatetime=" + createDatetime + ", remark="
+ remark + "]";
}}
6.查询QueryDemo.java
package com.cjq.one.test;
import java.util.List;import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;/**
* 演示hibernate查询
*
* @author cjq
*
*/
public class QueryDemo {
public static void main(String[] args) {
/*
* 1、对hibernate.cfg.xml这个核心的配置文件进行建模
* 2、建模后的对象configure去获取sessionfactory对象,sessionfactory对象中包含了数据库相关信息
* 3、通过sessionfactory对象去获取session会话
* 4、session开启事务(查询中是不需要)
* 5、操作数据库
* 6、提交事务(查询中是不需要)
* 7、释放资源
*/
//建模
Configuration configure = new Configuration().configure("/hibernate.cfg.xml");
//获取sessionfactory对象
SessionFactory sessionFactory = configure.buildSessionFactory();
//获取session会话
Session session = sessionFactory.openSession();
//操作数据库
List list = session.createQuery("from User").list();
for (Object obj : list) {
System.out.println(obj);
}
//释放资源
session.close();
}
}
结果如下:
7.增加AddDemo.java
package com.cjq.one.test;
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.cjq.one.entity.User;/**
* 演示hibernate新增
*
* @author cjq
*
*/
public class AddDemo {
public static void main(String[] args) {
Configuration configure = new Configuration().configure("/hibernate.cfg.xml");
SessionFactory sessionFactory = configure.buildSessionFactory();
Session session = sessionFactory.openSession();
Transaction transaction = session.beginTransaction();
User user=new User("zs", "123", "张三", "男", new Date(System.currentTimeMillis()), new Timestamp(System.currentTimeMillis()), "呵呵");
session.save(user);
transaction.commit();
session.close();
}
}
结果如下:
8.修改EditDemo.java
package com.cjq.one.test;
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.cjq.one.entity.User;/**
* 演示hibernate 修改
*
* @author cjq
*
*/
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.cjq.one.entity.User;/**
* 演示hibernate修改
*
* @author cjq
*
*/
public class EditDemo {
public static void main(String[] args) {
Configuration configure = new Configuration().configure("/hibernate.cfg.xml");
SessionFactory sessionFactory = configure.buildSessionFactory();
Session session = sessionFactory.openSession();
Transaction transaction = session.beginTransaction();
/*//第一种
User user=new User("zs", "12345", "张三", "男", new Date(System.currentTimeMillis()), new Timestamp(System.currentTimeMillis()), "哈哈");
user.setId(15);
session.update(user);*/
// 第二种
User user = session.get(User.class, 15);
user.setRealName("王力宏");
System.out.println(user);
transaction.commit();
session.close();
}
}
结果如下:
第一种修改方式:
第二种修改方式:
9.删除DelDemo
package com.cjq.one.test;
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.cjq.one.entity.User;/**
* 演示hibernate删除
*
* @author cjq
*
*/
public class DelDemo {
public static void main(String[] args) {
Configuration configure = new Configuration().configure("/hibernate.cfg.xml");
SessionFactory sessionFactory = configure.buildSessionFactory();
Session session = sessionFactory.openSession();
Transaction transaction = session.beginTransaction();
User user=new User();
user.setId(15);
session.delete(user);
transaction.commit();
session.close();
}
}
结果如下: