Hibernate 系列教程3-单表操作

工程截图



hibernate.cfg.xml

<!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>
        <!-- 必须配置的属性 -->
        <!-- 连接数据库信息 -->
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="connection.url">jdbc:mysql:///hibernate</property>
        <property name="connection.username">root</property>
        <property name="connection.password">admin</property>
        <!-- 方言属性：这个是实现跨数据库关键类 -->
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>

        <!-- 可选配置属性 -->
        <!-- 是否自动生成表：这里选用create便于测试 -->
        <property name="hbm2ddl.auto">create</property>
        <!-- 是否显示sql -->
        <property name="show_sql">true</property>
        <!-- 是否格式化sql -->
        <!-- <property name="format_sql">true</property> -->

        <!-- 以文件路径的方式加载映射文件 -->
        <mapping resource="com/jege/hibernate/single/table/User.hbm.xml" />
    </session-factory>
</hibernate-configuration>

User.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<!-- 映射文件 -->
<hibernate-mapping package="com.jege.hibernate.single.table">
    <!-- class表示由hibernate管理的一个持久对象,对应数据库的一个表 ，table表示数据库的表名 -->
    <class name="User" table="t_user">
        <!-- id元素是必须的，对应数据库是表的主键 -->
        <id name="id">
            <!-- generator表示数据库表的主键生成方式,一般都是使用native -->
            <!-- native表示自动选择数据库本地的策略: -->
            <!-- 对于mysql是AUTO_INCREMENT自增 -->
            <!-- 对于oracle是序列 -->
            <generator class="native" />
        </id>
        <!-- 使用property配置非主键属性 -->
        <!-- 可以column配置数据库表的不同于模型User的属性，如下username属性对应表的name字段 -->
        <property name="username" column="name" />
        <property name="password" />
    </class>
</hibernate-mapping>

User.java

package com.jege.hibernate.single.table;

/**
 * @author JE哥
 * @email 1272434821@qq.com
 * @description: 模型对象
 */
public class User {
  private Long id;
  private String username;
  private String password;

  public User() {

  }

  public User(Long id) {
    this.id = id;
  }

  public Long getId() {
    return id;
  }

  public void setId(Long 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;
  }

  @Override
  public String toString() {
    return "User [id=" + id + ", username=" + username + ", password=" + password + "]";
  }

}

CrudTest

package com.jege.hibernate.single.table;

import java.util.List;

import org.hibernate.Query;
import org.hibernate.Session;
import org.junit.Before;
import org.junit.Test;

import com.jege.hibernate.util.HibernateUtils;

/**
 * @author JE哥
 * @email 1272434821@qq.com
 * @description: crud测试类
 */
public class CrudTest {

  // 在每个@Test之前自动执行，先保存数据
  @Before
  public void before() throws Exception {
    User user = new User();
    user.setUsername("jege");
    user.setPassword("1272434821");

    Session session = HibernateUtils.INSTANCE.getSession();
    session.beginTransaction();
    session.save(user);
    session.getTransaction().commit();
    session.close();
  }

  @Test
  public void save() throws Exception {

  }

  @Test
  public void update() throws Exception {
    Session session = HibernateUtils.INSTANCE.getSession();
    session.beginTransaction();

    User user = (User) session.get(User.class, 1L);
    user.setUsername("JavaEEGe");
    user.setPassword("1272434821@qq.com");

    session.update(user);
    session.getTransaction().commit();
    session.close();
  }

  @Test
  public void delete() throws Exception {

    Session session = HibernateUtils.INSTANCE.getSession();
    session.beginTransaction();

    User user = (User) session.get(User.class, 1L);
    if (user != null) {
      session.delete(user);
    }

    session.getTransaction().commit();
    session.close();
  }

  @Test
  public void get() throws Exception {
    Session session = HibernateUtils.INSTANCE.getSession();
    User user = (User) session.get(User.class, 1L);
    System.out.println(user);
    session.close();
  }

  @Test
  public void getAll() throws Exception {
    Session session = HibernateUtils.INSTANCE.getSession();
    Query query = session.createQuery("select u from User u");
    List<User> list = query.list();
    for (User user : list) {
      System.out.println(user);
    }
    session.close();
  }

}

源码地址

https://github.com/je-ge/hibernate

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