第五章.MyBatis高级映射

5.1   新建数据库准备

CREATE TABLE `finacial_products` (
  `product_id` int(11) NOT NULL AUTO_INCREMENT,
  `name` varchar(32) NOT NULL COMMENT '理财产品名称',
  `price` float(10,1) NOT NULL COMMENT '理财产品定价',
  `detail` text COMMENT '理财产品描述',
  `pic` varchar(64) DEFAULT NULL COMMENT '理财产品图片',
  `invasttime` datetime NOT NULL COMMENT '理财产品收益日期',
  PRIMARY KEY (`product_id`)
) ；

CREATE TABLE `customer` (
  `cus_id` int(11) NOT NULL AUTO_INCREMENT,
  `username` varchar(32) NOT NULL COMMENT '用户名称',
  `acno` varchar(32) DEFAULT NULL COMMENT '卡号',
  `gender` varchar(4) DEFAULT NULL COMMENT '性别',
  `phone` varchar(256) DEFAULT NULL COMMENT '电话',
  PRIMARY KEY (`cus_id`)
)；

CREATE TABLE `batch` (
  `batch_id` int(11) NOT NULL AUTO_INCREMENT,
  `cus_id` int(11) NOT NULL COMMENT '创建批次用户id',
  `number` varchar(32) NOT NULL COMMENT '批次编码',
  `createtime` datetime NOT NULL COMMENT '创建批次时间',
  `note` varchar(100) DEFAULT NULL COMMENT '备注',
  PRIMARY KEY (`batch_id`),
  KEY `FK_batch_1` (`cus_id`),
  CONSTRAINT `FK_batch_id` FOREIGN KEY (`cus_id`) REFERENCES `customer` (`cus_id`) ON DELETE NO ACTION ON UPDATE NO ACTION
)；

CREATE TABLE `batchdetail` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `batch_id` int(11) NOT NULL COMMENT '批次id',
  `product_id` int(11) NOT NULL COMMENT '理财产品id',
  `product_num` int(11) DEFAULT NULL COMMENT '理财产品购买数量',
  PRIMARY KEY (`id`),
  KEY `FK_batchdetail_1` (`batch_id`),
  KEY `FK_batchdetail_2` (`product_id`),
  CONSTRAINT `FK_batchdetai_1` FOREIGN KEY (`batch_id`) REFERENCES `batch` (`batch_id`) ON DELETE NO ACTION ON UPDATE NO ACTION,
  CONSTRAINT `FK_batchdetai_2` FOREIGN KEY (`product_id`) REFERENCES `finacial_products` (`product_id`) ON DELETE NO ACTION ON UPDATE NO ACTION
)；

5.2   一对一查询

新建类在包  cn.com.mybatis.po

Batch.java
getter/setter方法

public class Batch {

    private int batch_id;
    private int cus_id;  
    private String number; 
    private Date createtime;
    private String note;
.....
}

BatchCustomer.java

public class BatchCustomer extends Batch{
    private String username;
    private String acno;
    ...
}

一对一查询

使用resultType实现

 UserMapper.xml

    <select id="findBatchCustomer" resultType="cn.com.mybatis.po.BatchCustomer">
             SELECT   
          BATCH.*,  
          CUSTOMER.username,  
          CUSTOMER.acno   
        FROM  
          BATCH,  
          CUSTOMER   
        WHERE BATCH.cus_id = CUSTOMER.cus_id  
    </select>

MyBatisTest.java  

　　　　　　@Test  
        public void testBatchCustomer() throws Exception{  
              
            SqlSession sqlSession = dataConn.getSqlSession();  
              
            //调用userMapper的方法  
            List<BatchCustomer> bcList=sqlSession.selectList("test.findBatchCustomer");
            if(bcList!=null){
                BatchCustomer batchCustomer = null;
                SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); 
                for (int i = 0; i < bcList.size(); i++) {
                    batchCustomer = bcList.get(i);
                    System.out.println("卡号为"+batchCustomer.getAcno()+"的名为"
                            +batchCustomer.getUsername()+"的客户:\n于"
                            +sdf.format(batchCustomer.getCreatetime())+"采购了批次号为"
                            +batchCustomer.getNumber()+"的一批理财产品");
                }
            }
            sqlSession.close();
        } 

 运行的结果：

DEBUG [main] - Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@480bdb19]
DEBUG [main] - ==>  Preparing: SELECT BATCH.*, CUSTOMER.username, CUSTOMER.acno FROM BATCH, CUSTOMER WHERE BATCH.cus_id = CUSTOMER.cus_id 
DEBUG [main] - ==> Parameters: 
DEBUG [main] - <==      Total: 1
卡号为622848的名为Mr的客户:
于2018-10-04 16:47:41采购了批次号为牛奶的一批理财产品
DEBUG [main] - Resetting autocommit to true on JDBC Connection [com.mysql.jdbc.JDBC4Connection@480bdb19]
DEBUG [main] - Closing JDBC Connection [com.mysql.jdbc.JDBC4Connection@480bdb19]

 数据库的内容

customer表：

batch表：

 使用resultMap实现

新建两个类
Customer.java

public class Customer implements Serializable{
    private int cus_id;
    private String username;
    private String acno;
    private String gender;
    private String phone;
    private List<Batch> batchList;
...
}

BatchItem.java

import java.util.Date;
import java.util.List;
public class BatchItem {
    private int batch_id;
    private int cus_id;  
    private String number; 
    private Date createtime;
    private String note;
    private Customer customer;
...
}

UserMapper.xml

    <resultMap type="cn.com.mybatis.po.BatchItem" id="BatchInfoMap">   
         <id column="batch_id" property="batch_id"/>  
         <result column="cus_id" property="cus_id"/>  
         <result column="number" property="number"/>  
         <result column="createtime" property="createtime" javaType="java.util.Date"/>  
         <result column="note" property="note"/>  
         <association property="customer" javaType="cn.com.mybatis.po.Customer">  
             <id column="cus_id" property="cus_id"/>  
             <result column="username" property="username"/>  
             <result column="acno" property="acno"/>  
             <result column="gender" property="gender"/>
             <result column="phone" property="phone"/>    
         </association>  
    </resultMap>  
    
    <select id="findBatchCustomerToMap" resultMap="BatchInfoMap">  
        SELECT   
          BATCH.*,  
          CUSTOMER.username,  
          CUSTOMER.acno   
        FROM  
          BATCH,  
          CUSTOMER   
        WHERE BATCH.cus_id = CUSTOMER.cus_id  
    </select>

 MyBatisTest.java  

    @Test  
        public void testBatchCustomerToMap() throws Exception{  
              
            SqlSession sqlSession=dataConn.getSqlSession();    
              
            //调用userMapper的方法  
            List<BatchItem> bcList=sqlSession.selectList("findBatchCustomerToMap");
            if(bcList!=null){
                BatchItem batchItem = null;
                Customer customer = null;
                SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); 
                for (int i = 0; i < bcList.size(); i++) {
                    batchItem = bcList.get(i);//取出批次对象
                    customer = batchItem.getCustomer();//取出该批次的用户信息
                    System.out.println("卡号为"+customer.getAcno()+"的名为"
                            +customer.getUsername()+"的客户:\n于"
                            +sdf.format(batchItem.getCreatetime())+"采购了批次号为"
                            +batchItem.getNumber()+"的一批理财产品");
                }
            }
            sqlSession.close();
        } 

 控制台结果：

DEBUG [main] - Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@7e2d773b]
DEBUG [main] - ==>  Preparing: SELECT BATCH.*, CUSTOMER.username, CUSTOMER.acno FROM BATCH, CUSTOMER WHERE BATCH.cus_id = CUSTOMER.cus_id 
DEBUG [main] - ==> Parameters: 
DEBUG [main] - <==      Total: 1
卡号为622848的名为Mr的客户:
于2018-10-04 16:47:41采购了批次号为牛奶的一批理财产品
DEBUG [main] - Resetting autocommit to true on JDBC Connection [com.mysql.jdbc.JDBC4Connection@7e2d773b]

 一对多查询

 首先对数据路进行补充：

batch表：

 batchdetail表：

 customer表：

finacial_products表：

在数据库中测试指令：

SELECT   
    BATCH.*,  
    CUSTOMER.username,  
    CUSTOMER.acno,
        BATCHDETAIL.product_id,
    BATCHDETAIL.product_num
    FROM  
    BATCH,  
    CUSTOMER,
    BATCHDETAIL 
    WHERE BATCH.cus_id = CUSTOMER.cus_id AND BATCHDETAIL.batch_id=BATCH.batch_id;

得到：

Batch.java
添加一句代码：

public class Batch {

    private int batch_id;
    private int cus_id;  
    private String number; 
    private Date createtime;
    private String note;
    private List<BatchDetail> batchDetials;
...
}

BatchDetail.java

public class BatchDetail {
    private int id;  
    private int batch_id;  
    private int product_id;  
    private int product_num;
...
}

 BatchItem.java

添加

    //批次包含的理财产品订购信息
    private List<BatchDetail> batchDetails;

BatchDatas.java

public class BatchDatas {
    private int batch_id;
    private int cus_id;  
    private String number; 
    private Date createtime;
    private String note;
    private Customer customer;
    
    private List<BatchDetail> batchDetails;
...
}

 UserMapper.xml

 <resultMap type="cn.com.mybatis.po.BatchItem" id="BatchAndBatchDetailResultMap"   
               extends="BatchInfoMap">  
        <collection property="batchDetails" ofType="cn.com.mybatis.po.BatchDetail">  
            <!-- id:订单明细的唯一标识 -->  
            <id column="id" property="id"/>  
            <result column="batch_id" property="batch_id"/>  
            <result column="product_id" property="product_id"/>  
            <result column="product_num" property="product_num"/>  
        </collection>  
    </resultMap>
    
    <select id="findBatchAndBatchDetail" resultMap="BatchAndBatchDetailResultMap">  
        SELECT   
          BATCH.*,  
          CUSTOMER.username,  
          CUSTOMER.acno,
          BATCHDETAIL.product_id,
          BATCHDETAIL.product_num
        FROM  
          BATCH,  
          CUSTOMER,
          BATCHDETAIL 
        WHERE BATCH.cus_id = CUSTOMER.cus_id AND BATCHDETAIL.batch_id=BATCH.batch_id     
    </select>  

MyBatisTest.java

        @Test  
        public void testfindBatchAndBatchDetail() throws Exception{  
              
            SqlSession sqlSession=dataConn.getSqlSession();    
              
            //调用userMapper的方法  
            BatchItem batchItem=sqlSession.selectOne("findBatchAndBatchDetail");
            if(batchItem!=null){
                SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); 
                Customer customer = batchItem.getCustomer();//取出该批次的用户信息
                //取出该批次订购的理财产品信息
                List<BatchDetail> batchDetails = batchItem.getBatchDetails();
                System.out.println("卡号为"+customer.getAcno()+"的名为"
                        +customer.getUsername()+"的客户:\n于"
                        +sdf.format(batchItem.getCreatetime())+"采购了批次号为"
                        +batchItem.getNumber()+"的一批理财产品，详情如下：");
                BatchDetail batchDetail = null;
                if(batchDetails!=null){
                    for (int i = 0; i < batchDetails.size(); i++) {
                        batchDetail = batchDetails.get(i);
                        System.out.println("id为"+batchDetail.getProduct_id()
                                +"的理财产品"+batchDetail.getProduct_num()+"份");
                    }
                    
                }
                
            }
            sqlSession.close();
        } 
        

 测试结果：

DEBUG [main] - ==>  Preparing: SELECT BATCH.*, CUSTOMER.username, CUSTOMER.acno, BATCHDETAIL.product_id, 
　　BATCHDETAIL.product_num FROM BATCH, CUSTOMER, BATCHDETAIL WHERE BATCH.cus_id = CUSTOMER.cus_id AND 
　　BATCHDETAIL.batch_id=BATCH.batch_id 
DEBUG [main] - ==> Parameters: 
DEBUG [main] - <==      Total: 2
卡号为622848的名为Mr的客户:
于2018-10-04 16:47:41采购了批次号为牛奶的一批理财产品，详情如下：
id为1的理财产品100份
id为2的理财产品50份
DEBUG [main] - Resetting autocommit to true on JDBC Connection [com.mysql.jdbc.JDBC4Connection@2173f6d9]

 多对多的查询

Customer.java

public class Customer implements Serializable{
    private int cus_id;
    private String username;
    private String acno;
    private String gender;
    private String phone;
    private List<Batch> batchList;
...
}

Batch.java

public class Batch {

    private int batch_id;
    private int cus_id;  
    private String number; 
    private Date createtime;
    private String note;
    private List<BatchDetail> batchDetials;
...
}

BatchDetail.java

public class BatchDetail {
    private int id;  
    private int batch_id;  
    private int product_id;  
    private int product_num;
    private FinacialProduct finacialProduct;
...
}

FinacialProduct.java

public class FinacialProduct {
    private int id;
    private String name;
    private double price;
    private String detail;
    private String imgpath;
    private Date invattime;
...
}

 UserMapper.xml

 <resultMap type="cn.com.mybatis.po.Customer" id="UserAndProductsResultMap">  
        <!-- 客户信息 -->   
        <result column="username" property="username"/>  
        <result column="acno" property="acno"/>
          
        <!--批次订单信息，一个客户对应多个订单-->  
        <collection property="batchList" ofType="cn.com.mybatis.po.Batch">  
            <id column="batch_id" property="batch_id"/>  
            <result column="cus_id" property="cus_id"/>  
            <result column="number" property="number"/>  
            <result column="createtime" property="createtime" javaType="java.util.Date"/>  
            <result column="note" property="note"/>  
              
            <collection property="batchDetials" ofType="cn.com.mybatis.po.BatchDetail">   
                <!-- id:订单明细的唯一标识 -->  
                <id column="id" property="id"/>  
                <result column="batch_id" property="batch_id"/>  
                <result column="product_id" property="product_id"/>  
                <result column="product_num" property="product_num"/>  
              
                <association property="finacialProduct" javaType="cn.com.mybatis.po.FinacialProduct">  
                    <id column="product_id" property="id"/>  
                    <result column="name" property="name"/>  
                    <result column="price" property="price"/>  
                    <result column="detail" property="detail"/>  
                </association>  
            </collection>  
        </collection>  
    </resultMap>  
    
    <select id="findUserAndProducts" resultMap="UserAndProductsResultMap">  
        SELECT   
          BATCH.*,  
          CUSTOMER.username,  
          CUSTOMER.acno,
          BATCHDETAIL.product_id,
          BATCHDETAIL.product_num,
          FINACIAL_PRODUCTS.name,  
          FINACIAL_PRODUCTS.detail,  
          FINACIAL_PRODUCTS.price  
        FROM  
          BATCH,  
          CUSTOMER,
          BATCHDETAIL,
          FINACIAL_PRODUCTS 
        WHERE BATCH.cus_id = CUSTOMER.cus_id 
        AND BATCHDETAIL.batch_id=BATCH.batch_id
        AND FINACIAL_PRODUCTS.product_id=BATCHDETAIL.product_id;  
    </select> 

MybatisTest.java

@Test  
        public void testfindCustomerAndProducts() throws Exception{  
              
            SqlSession sqlSession=dataConn.getSqlSession();    
              
            //调用userMapper的方法，获取所有用户信息(以及从属批次信息)  
            List<Customer> customerList=sqlSession.selectList("findUserAndProducts");
            if(customerList!=null){
                SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
                Customer customer = null;
                for (int i = 0; i < customerList.size(); i++) {
                    customer = customerList.get(i);
                    //1.获取用户基本信息
                    System.out.println("卡号为"+customer.getAcno()+"的名为"
                            +customer.getUsername()+"的客户:");
                    //2.获取用户下的所有批次订单信息
                    List<Batch> batchList=customer.getBatchList();
                    Batch batch = null;
                    for (int j = 0; j < batchList.size(); j++) {
                        batch = batchList.get(j);
                        System.out.println("于"
                                +sdf.format(batch.getCreatetime())+"采购了批次号为"
                                +batch.getNumber()+"的一批理财产品，详情如下：");
                        //3.获取一个批次的明细
                        List<BatchDetail> batchDetails = batch.getBatchDetials();
                        BatchDetail batchDetail = null;
                        FinacialProduct finacialProduct = null;
                        for (int k = 0; k < batchDetails.size(); k++) {
                            batchDetail = batchDetails.get(k);
                            System.out.println("id为"+batchDetail.getProduct_id()
                                    +"的理财产品"+batchDetail.getProduct_num()+"份。");
                            //4.获取每个批次明细中的理财产品详细信息
                            finacialProduct = batchDetail.getFinacialProduct();
                            System.out.println("该理财产品的详细信息为：\n"
                                    +"产品名称:"+finacialProduct.getName()
                                    +"|产品价格:"+finacialProduct.getPrice()
                                    +"|产品简介:"+finacialProduct.getDetail());
                        }    
                    }
                    System.out.println("**************************************");
                }
                
            }
            sqlSession.close();
        } 

实测结果：

DEBUG [main] - Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@7a187f14]
DEBUG [main] - ==>  Preparing: SELECT BATCH.*, CUSTOMER.username, CUSTOMER.acno, BATCHDETAIL.product_id, 
　　BATCHDETAIL.product_num, FINACIAL_PRODUCTS.name, FINACIAL_PRODUCTS.detail, FINACIAL_PRODUCTS.price FROM BATCH,
 　　CUSTOMER, BATCHDETAIL, FINACIAL_PRODUCTS WHERE BATCH.cus_id = CUSTOMER.cus_id AND BATCHDETAIL.batch_id=
　　BATCH.batch_id AND FINACIAL_PRODUCTS.product_id=BATCHDETAIL.product_id; 
DEBUG [main] - ==> Parameters: 
DEBUG [main] - <==      Total: 2
卡号为622848的名为Mr的客户:
于2018-10-04 16:47:41采购了批次号为牛奶的一批理财产品，详情如下：
id为1的理财产品100份。
该理财产品的详细信息为：
产品名称:花生|产品价格:12.0|产品简介:酒鬼花生
id为2的理财产品50份。
该理财产品的详细信息为：
产品名称:方便面|产品价格:2.0|产品简介:康师傅
**************************************

延迟加载

 sqlMapConfig.xml

 添加代码：

    <settings>
         <setting name="lazyLoadingEnabled" value="true"/>
         <setting name="aggressiveLazyLoading" value="false"/>
     </settings>

 UserMapper.xml

    <!-- 延迟加载的resultMap -->  
    <resultMap id="BatchUserLazyLoadingResultMap" type="cn.com.mybatis.po.BatchItem">  
        <!-- 对订单信息进行映射配置 -->  
        <id column="batch_id" property="batch_id"/>  
        <result column="cus_id" property="cus_id"/>  
        <result column="number" property="number"/>  
        <result column="createtime" property="createtime" javaType="java.util.Date"/>  
        <result column="note" property="note"/> 
        <!-- 实现延迟加载用户信息 -->  
        <association property="customer" javaType="cn.com.mybatis.po.Customer" select="findCustomerById" column="cus_id">  
        </association>  
    </resultMap>  
    
    <select id="findBatchUserLazyLoading" resultMap="BatchUserLazyLoadingResultMap">  
        SELECT * FROM BATCH 
    </select> 
    
   
　　<select id="findCustomerById" parameterType="int" resultType="cn.com.mybatis.po.Customer">  
        SELECT * FROM CUSTOMER WHERE cus_id=#{id}
    </select> 

 MyBatisTest.java

　　     @Test  
        public void testFindBatchCustomerLazyLoading() throws Exception{  
              
            SqlSession sqlSession=dataConn.getSqlSession();
            //调用userMapper的方法，获取所有订单信息(未加载关联的用户信息)  
              List<BatchItem> batchItemList=sqlSession.selectList("findBatchUserLazyLoading"); 
              BatchItem batchItem = null;
              Customer customer = null;
            for (int i = 0; i < batchItemList.size(); i++) {  
                batchItem = batchItemList.get(i);  
                System.out.println("订单编号："+batchItem.getNumber());
                //执行getCustomer时才会去查询用户信息，这里实现了延迟加载  
                customer=batchItem.getCustomer();  
                System.out.println("订购用户姓名:"+customer.getUsername());  
            }  
            sqlSession.close();
        }  

结果：

DEBUG [main] - Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@7a187f14]
DEBUG [main] - ==>  Preparing: SELECT * FROM BATCH 
DEBUG [main] - ==> Parameters: 
DEBUG [main] - <==      Total: 2
订单编号：牛奶
DEBUG [main] - ==>  Preparing: SELECT * FROM CUSTOMER WHERE cus_id=? 
DEBUG [main] - ==> Parameters: 1(Integer)
DEBUG [main] - <==      Total: 1
订购用户姓名:Mr
订单编号：方便面
订购用户姓名:Mr
DEBUG [main] - Resetting autocommit to true on JDBC Connection [com.mysql.jdbc.JDBC4Connection@7a187f14]
DEBUG [main] - Closing JDBC Connection [com.mysql.jdbc.JDBC4Connection@7a187f14]
DEBUG [main] - Returned connection 2048425748 to pool.

 Mappwe动态代理

创建新的mapper文件

 

CustomerMapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper
PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="cn.com.mybatis.mapper.CustomerMapper">

    <!-- 查询用户 -->
    <select id="findCustomerById" parameterType="int" resultType="cn.com.mybatis.po.Customer">  
      SELECT * FROM CUSTOMER WHERE cus_id=#{cus_id}
    </select>  
    <!-- 新增用户 -->   
    <insert id="insertCustomer" parameterType="cn.com.mybatis.po.Customer">    
        INSERT INTO CUSTOMER(username,acno,gender,phone) 
            value(#{username},#{acno},#{gender},#{phone})  
    </insert>
    <!-- 删除用户 -->  
    <delete id="deleteCustomer" parameterType="java.lang.Integer">  
        DELETE FROM CUSTOMER WHERE cus_id=#{cus_id}
    </delete>  
    <!-- 修改用户 -->  
    <update id="updateCustomerAcNo" parameterType="cn.com.mybatis.po.Customer" >
        UPDATE CUSTOMER SET acno = #{acno} WHERE cus_id=#{cus_id}
    </update>


</mapper>

 注意：引入文件除非使用的是package方法

 SqlMapConfig.xml

     <mappers>
         <mapper resource="sqlmap/UserMapper.xml"/>
         <mapper resource="sqlmap/CustomerMapper.xml"/>
     </mappers>

新建包以及接口

CustomerMapper.java

public interface CustomerMapper {

    //根据Id查询用户信息  
    public Customer findCustomerById(int id) throws Exception;  
      
    //添加用户信息  
    public void insertCustomer(Customer customer) throws Exception;  
      
    //删除用户信息  
    public void deleteCustomer(int id) throws Exception;  
      
    //修改用户信息  
    public void updateCustomerAcNo(Customer customer) throws Exception;  
}

MyBatisTest.java

    
        //动态代理
        @Test  
        public void testFindCustomerOnMapper() throws Exception{  
            SqlSession sqlSession=dataConn.getSqlSession();    
              
            //获取Mapper代理  
            CustomerMapper customerMapper=sqlSession.getMapper(CustomerMapper.class);
            //执行Mapper代理对象的查询方法
            Customer customer=customerMapper.findCustomerById(1);
            System.out.println("用户姓名："+customer.getUsername()+"|"
                    +"卡号："+customer.getAcno());
            sqlSession.close();
        }

结果：

DEBUG [main] - Created connection 331510866.
DEBUG [main] - Setting autocommit to false on JDBC Connection [com.mysql.jdbc.JDBC4Connection@13c27452]
DEBUG [main] - ==>  Preparing: SELECT * FROM CUSTOMER WHERE cus_id=? 
DEBUG [main] - ==> Parameters: 1(Integer)
DEBUG [main] - <==      Total: 1
用户姓名：Mr|卡号：622848
DEBUG [main] - Resetting autocommit to true on JDBC Connection [com.mysql.jdbc.JDBC4Connection@13c27452]
DEBUG [main] - Closing JDBC Connection [com.mysql.jdbc.JDBC4Connection@13c27452]
DEBUG [main] - Returned connection 331510866 to pool.