Hibernate_01

*:first-child {
margin-top: 0 !important;
}

body>*:last-child {
margin-bottom: 0 !important;
}

/* BLOCKS
=============================================================================*/

p, blockquote, ul, ol, dl, table, pre {
margin: 15px 0;
}

/* HEADERS
=============================================================================*/

h1, h2, h3, h4, h5, h6 {
margin: 20px 0 10px;
padding: 0;
font-weight: bold;
-webkit-font-smoothing: antialiased;
}

h1 tt, h1 code, h2 tt, h2 code, h3 tt, h3 code, h4 tt, h4 code, h5 tt, h5 code, h6 tt, h6 code {
font-size: inherit;
}

h1 {
font-size: 28px;
color: #000;
}

h2 {
font-size: 24px;
border-bottom: 1px solid #ccc;
color: #000;
}

h3 {
font-size: 18px;
}

h4 {
font-size: 16px;
}

h5 {
font-size: 14px;
}

h6 {
color: #777;
font-size: 14px;
}

body>h2:first-child, body>h1:first-child, body>h1:first-child+h2, body>h3:first-child, body>h4:first-child, body>h5:first-child, body>h6:first-child {
margin-top: 0;
padding-top: 0;
}

a:first-child h1, a:first-child h2, a:first-child h3, a:first-child h4, a:first-child h5, a:first-child h6 {
margin-top: 0;
padding-top: 0;
}

h1+p, h2+p, h3+p, h4+p, h5+p, h6+p {
margin-top: 10px;
}

/* LINKS
=============================================================================*/

a {
color: #4183C4;
text-decoration: none;
}

a:hover {
text-decoration: underline;
}

/* LISTS
=============================================================================*/

ul, ol {
padding-left: 30px;
}

ul li > :first-child,
ol li > :first-child,
ul li ul:first-of-type,
ol li ol:first-of-type,
ul li ol:first-of-type,
ol li ul:first-of-type {
margin-top: 0px;
}

ul ul, ul ol, ol ol, ol ul {
margin-bottom: 0;
}

dl {
padding: 0;
}

dl dt {
font-size: 14px;
font-weight: bold;
font-style: italic;
padding: 0;
margin: 15px 0 5px;
}

dl dt:first-child {
padding: 0;
}

dl dt>:first-child {
margin-top: 0px;
}

dl dt>:last-child {
margin-bottom: 0px;
}

dl dd {
margin: 0 0 15px;
padding: 0 15px;
}

dl dd>:first-child {
margin-top: 0px;
}

dl dd>:last-child {
margin-bottom: 0px;
}

/* CODE
=============================================================================*/

pre, code, tt {
font-size: 12px;
font-family: Consolas, "Liberation Mono", Courier, monospace;
}

code, tt {
margin: 0 0px;
padding: 0px 0px;
white-space: nowrap;
border: 1px solid #eaeaea;
background-color: #f8f8f8;
border-radius: 3px;
}

pre>code {
margin: 0;
padding: 0;
white-space: pre;
border: none;
background: transparent;
}

pre {
background-color: #f8f8f8;
border: 1px solid #ccc;
font-size: 13px;
line-height: 19px;
overflow: auto;
padding: 6px 10px;
border-radius: 3px;
}

pre code, pre tt {
background-color: transparent;
border: none;
}

kbd {
-moz-border-bottom-colors: none;
-moz-border-left-colors: none;
-moz-border-right-colors: none;
-moz-border-top-colors: none;
background-color: #DDDDDD;
background-image: linear-gradient(#F1F1F1, #DDDDDD);
background-repeat: repeat-x;
border-color: #DDDDDD #CCCCCC #CCCCCC #DDDDDD;
border-image: none;
border-radius: 2px 2px 2px 2px;
border-style: solid;
border-width: 1px;
font-family: "Helvetica Neue",Helvetica,Arial,sans-serif;
line-height: 10px;
padding: 1px 4px;
}

/* QUOTES
=============================================================================*/

blockquote {
border-left: 4px solid #DDD;
padding: 0 15px;
color: #777;
}

blockquote>:first-child {
margin-top: 0px;
}

blockquote>:last-child {
margin-bottom: 0px;
}

/* HORIZONTAL RULES
=============================================================================*/

hr {
clear: both;
margin: 15px 0;
height: 0px;
overflow: hidden;
border: none;
background: transparent;
border-bottom: 4px solid #ddd;
padding: 0;
}

/* TABLES
=============================================================================*/

table th {
font-weight: bold;
}

table th, table td {
border: 1px solid #ccc;
padding: 6px 13px;
}

table tr {
border-top: 1px solid #ccc;
background-color: #fff;
}

table tr:nth-child(2n) {
background-color: #f8f8f8;
}

/* IMAGES
=============================================================================*/

img {
max-width: 100%
}
-->

Hibernate

hibernate是一个持久层orm框架，目的：简化项目开发，提高开发效率。

快速入门

• 下载hibernate，然后导入hibernate->lib->required下面的所有jar包，还有就是数据库驱动的jar包。
• 创建表cst_customer

  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_address` varchar(128) DEFAULT NULL COMMENT '客户联系地址',
  `cust_phone` varchar(64) DEFAULT NULL COMMENT '客户联系电话',
  PRIMARY KEY (`cust_id`)
  ) ENGINE=InnoDB AUTO_INCREMENT=1 DEFAULT CHARSET=utf8;
  

• 创建相应的实体类 Customer.java

    public class Customer implements Serializable {
    private static final long serialVersionUID = 1L;
    private Long id;// 主键
    private String custName;// 客户姓名
    private String custSource; // 客户来源
    private String custIndustry; // 所属行业
    private String custLevel; // 客户级别
    private String custAddress; // 地址
    private String custPhone; // 电话
  
    public Long getId() {
        return id;
    }
    public void setId(Long id) {
        this.id = id;
    }
    public String getCustName() {
        return custName;
    }
    public void setCustName(String custName) {
        this.custName = custName;
    }
    public String getCustSource() {
        return custSource;
    }
    public void setCustSource(String custSource) {
        this.custSource = custSource;
    }
    public String getCustIndustry() {
        return custIndustry;
    }
    public void setCustIndustry(String custIndustry) {
        this.custIndustry = custIndustry;
    }
    public String getCustLevel() {
        return custLevel;
    }
    public void setCustLevel(String custLevel) {
        this.custLevel = custLevel;
    }
    public String getCustAddress() {
        return custAddress;
    }
    public void setCustAddress(String custAddress) {
        this.custAddress = custAddress;
    }
    public String getCustPhone() {
        return custPhone;
    }
    public void setCustPhone(String custPhone) {
        this.custPhone = custPhone;
    }
    @Override
    public String toString() {
        return "Customer [id=" + id + ", custName=" + custName + ", custSource=" + custSource + ", custIndustry="
                + custIndustry + ", custLevel=" + custLevel + ", custAddress=" + custAddress + ", custPhone="
                + custPhone + "]";
    }
  }
  

• 创建对应的配置文件 Customer.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
        name : 实体类的全限定名
        table : 对应数据库的表名(如果类名和数据库表的名字一样，可以省略table配置)
     -->
    <class name="com.xiaoshitou.domain.Customer" table="cst_customer">
        <!-- id标签：主键
            name ： 实体类中的id
            column : 数据库中主键的名字
         -->
        <id name="id" column="cust_id">
            <!-- gennerator class：主键的生成策略；native表示，主键由数据库自动维护 -->
            <generator class="native"></generator>
        </id>
  
        <!-- property:主键以外的普通字段
         name=>实体类中的成员变量，column=>表中的字段名  -->
        <property name="custName" column="cust_name"></property>
        <property name="custSource" column="cust_source"></property>
        <property name="custIndustry" column="cust_industry"></property>
        <property name="custLevel" column="cust_level"></property>
        <property name="custAddress" column="cust_address"></property>
        <property name="custPhone" column="cust_phone"></property>
    </class>
  </hibernate-mapping>
  

• 编写hiberna核心配置文件：一定要放在src目录下，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>
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hibernate</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">123456</property>
        <!-- 配置数据库方言 -->
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
  
        <!-- 显示sql -->
        <property name="hibernate.show_sql">true</property>
        <!-- 格式化sql -->
        <property name="hibernate.format">true</property>
        <!-- create-drop:启动时会创建表，sessionFactory关闭时删除表,
            create: 每次都会重新创建表,
            update: 如果实体类和数据库的表字段不一样时，会修改数据库中的字段，保证实体类和数据库表是同步的,
            validate： 如果实体类和数据库表字段不一致时，会报错  -->
        <property name="hibernate.hbm2ddl.auto">update</property>
  
        <!-- 把实体类的配置文件加载到核心配置文件中 -->
        <mapping resource="com/xiaoshitou/domain/Customer.hbm.xml"/>
  
    </session-factory>
  </hibernate-configuration>
  

• 编写测试类，使用hibernate来添加一条数据

  /**
     * 快速入门：利用hibernate添加一条数据
     */
    @Test
    public void test01() {
        // 创造一个customer对象
        Customer customer = new Customer();
        customer.setCustName("东方科技");
        customer.setCustLevel("VIP");
        customer.setCustSource("朋友推荐");
        customer.setCustIndustry("无人机");
        customer.setCustAddress("东方1号路");
        customer.setCustPhone("8221365");
  
        // 利用hibernate完成保存
        Configuration configuration = new Configuration();
        configuration.configure();
        // 创建sessionFactory
        SessionFactory sessionFactory = configuration.buildSessionFactory();
        // 获取session
        Session session = sessionFactory.openSession();
        // 开启事务
        Transaction tx = session.beginTransaction();
        // 保存
        session.save(customer);
        // 提交事务，关闭资源
        tx.commit();
        session.close();
        sessionFactory.close();
    }
  

  hibernate 使用c3p0连接池

• 导入jar包：hibernate-release-5.0.7.Final\lib\optional\c3p0

• 在hibernate.cfg.xml中添加配置

  <?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>
        <!-- 使用c3p0连接池 -->
        <property name="hibernate.connection.provider_class">org.hibernate.connection.C3P0ConnectionProvider</property>
        <!-- 在数据库连接池中，最大连接数 -->
        <property name="hibernate.c3p0.max_size">20</property>
        <!-- 在数据库连接池中，最小连接数 -->
        <property name="hibernate.c3p0.min_size">5</property>
        <!-- 如果连接池中，某个连接空闲时间超过设置的时间，将会被从连接池冲清除 -->
        <property name="hibernate.c3p0.timeout">5000</property>
        <!-- 每个3000秒检查，连接池中的空闲连接,单位秒 -->
        <property name="hibernate.c3p0.idle_test_period">3000</property>
  
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/hibernate</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">123456</property>
        <!-- 配置数据库方言 -->
        <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
  
        <!-- 显示sql -->
        <property name="hibernate.show_sql">true</property>
        <!-- 格式化sql -->
        <property name="hibernate.format_sql">true</property>
        <!-- create-drop:启动时会创建表，sessionFactory关闭时删除表,
            create: 每次都会重新创建表,
            update: 如果实体类和数据库的表字段不一样时，会修改数据库中的字段，保证实体类和数据库表是同步的,
            validate： 如果实体类和数据库表字段不一致时，会报错  -->
        <property name="hibernate.hbm2ddl.auto">update</property>
  
        <!-- 把实体类的配置文件加载到核心配置文件中 -->
        <mapping resource="com/xiaoshitou/domain/Customer.hbm.xml"/>
  
    </session-factory>
  </hibernate-configuration>
  

  session中的saveOrUpdate方法:

• 如果对象中没有设置id,就会新增一条记录
• 如果对象中设置了id,并且数据库中，有对应id的记录，那么就是修改记录
• 如果对象中设置了id,在数据库中没有对应id的记录，那么将会执行失败，抛出异常。
  

  session中get和load方法的区别

• get是立即加载(立即执行sql语句)，load是延迟加载(在真正使用对象的属性时，才会发送sql语句)
• get返回的对象是要查询的实体对象，load返回的代理对象