Mybatis配置C3p0 和Druid連線池
阿新 • • 發佈：2018-11-16
普通java工程配置Mybatis 連線池
整體結構
匯入jar 包：
連結：https://pan.baidu.com/s/1aEpDPO9xRK1_shVsUpOEZA
提取碼：16nf
Mybatis 配置檔案：
<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration
PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
"http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration> 
資料庫連結資訊：
db.proterties
jdbcDriver=com.mysql.jdbc.Driver
jdbcUrl=jdbc:mysql://localhost:3306/chat
jdbcUser=root
jdbcPassword=root
檢視sql 執行日誌log4j.properties:
log報錯 因為log4j.properties檔案的路徑不在主路徑下面：
log4j:WARN No appenders could be found for logger (org.apache.ibatis.logging.LogFactory).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
這種情況下沒有打印出日誌, 說明應用並沒有對log4j進行初始化. 解決方法是要在應用啟動時就進行
PropertyConfigurator.configure("src/main/resource/log4j.properties");
配置：
log4j.rootLogger=info,stdout
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%-d{yyyy-MM-dd HH\:mm\:ss} %d %p [%c] -%m%n
# 列印sql語句:debug; 執行結果:trace
## 指定mapper配置檔案中的namespace
#com.feifan.mapper.UserMapper 單個介面
#com.feifan.mapper包下面所有的
log4j.logger.com.feifan.mapper =TRACE
效果：
2018-11-10 18:04:51 2018-11-10 18:04:51,067 DEBUG [com.feifan.mapper.UserMapper.findUser] -==> Preparing: select * from t_user where id=? and email=?
2018-11-10 18:04:51 2018-11-10 18:04:51,068 DEBUG [com.feifan.mapper.UserMapper.findUser] -==> Parameters: 2(Integer), 9090(String)
2018-11-10 18:04:51 2018-11-10 18:04:51,069 TRACE [com.feifan.mapper.UserMapper.findUser] -<== Columns: id, age, create_who, email, gender, name, pw, signtime
2018-11-10 18:04:51 2018-11-10 18:04:51,069 TRACE [com.feifan.mapper.UserMapper.findUser] -<== Row: 2, 10, dd, 9090, null, 二狗子, null, null
2018-11-10 18:04:51 2018-11-10 18:04:51,070 DEBUG [com.feifan.mapper.UserMapper.findUser] -<== Total: 1
兩個POJO類：
TbUser類：
public class TbUser implements Serializable {
private Integer id;
private String name;
private String pw;
private Integer age;
private String email;
private String gender;
private Date signTime;}
User類：
public class User implements Serializable{
private Integer id;
private Integer age;
private String createWho;
private String email;
private String gender;
private String name;
private String pw;
private Date signtime;
}
獲取Sqlsession 工具類：
import java.io.IOException;
import java.io.InputStream;
import javax.sql.DataSource;
import org.apache.ibatis.io.Resources;
import org.apache.ibatis.mapping.Environment;
import org.apache.ibatis.session.Configuration;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
public class MybatisUtils {
private static SqlSessionFactory sqlSessionFactory=null;
private MybatisUtils() {}
static{
String resource="main/resource/MybatisConfig.xml";
try {
//讀取配置檔案 獲取sqlsessionFactory
InputStream inputStream = Resources.getResourceAsStream(resource);
sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream);
Configuration configuration = sqlSessionFactory.getConfiguration();
System.out.println(configuration);
Environment environment = configuration.getEnvironment();
System.out.println(environment);
DataSource dataSource = environment.getDataSource();
System.out.println(dataSource);
} catch (IOException e) {
e.printStackTrace();
}
}
/**
* 獲取sqlSession
* @return
*/
public static SqlSession getSqlSession(){
SqlSession sqlSession = sqlSessionFactory.openSession();
return sqlSession;
}
}
整合c3p0/Druid連線池:
Mybatis 沒有幫開發者實現 c3p0 資料庫連線池，故需要使用者自己實現 c3p0 來載入資料連線池。其實很簡單的，只要繼承 UnpooledDataSourceFactory 並把 dataSource 實現。我們的 mybatis 就實現了 c3p0 資料庫連線池。
C3p0連線池
import org.apache.ibatis.datasource.unpooled.UnpooledDataSourceFactory;
import com.mchange.v2.c3p0.ComboPooledDataSource;
/** Mybatis 沒有幫開發者實現 c3p0 資料庫連線池，
* 故需要使用者自己實現 c3p0 來載入資料連線池
* 。其實很簡單的，只要繼承 UnpooledDataSourceFactory 並把 dataSource 實現。
* 我們的 mybatis 就實現了 c3p0 資料庫連線池。*/
public class c3p0DatasourceFactory extends UnpooledDataSourceFactory{
public c3p0DatasourceFactory() {
this.dataSource=new ComboPooledDataSource();
}
}
Druid連線池
import org.apache.ibatis.datasource.unpooled.UnpooledDataSourceFactory;
import com.alibaba.druid.pool.DruidDataSource;
public class DruidDataSourceFactory extends UnpooledDataSourceFactory{
public DruidDataSourceFactory() {
this.dataSource=new DruidDataSource();
}
}
介面檔案：
import com.feifan.pojo.TbUser;
public interface TbUserMapper {
TbUser selectById(Integer id);
}
UserMapper介面：
import org.apache.ibatis.annotations.Param;
import com.feifan.pojo.User;
public interface UserMapper {
User selectById(Integer id);
int insertUser(User user);
void insertUserTwo(User user);
/**多個引數可以使用集合的 方式傳遞，map等*/
User findUser(@Param("id")Integer id,@Param("email") String email);
}
sql對映檔案：
UserMapper.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">
<!-- namespace 介面全名 -->
<mapper namespace="com.feifan.mapper.UserMapper">
<!-- statement -->
<select id="selectById" parameterType="int" resultType="User" >
SELECT * FROM t_user where id=#{id}
</select>
<!-- 通過useGeneratedKeys="true" keyProperty="id" 獲取剛剛插入的自增主鍵id, keyProperty="id
並把賦值給物件的屬性id
-->
<insert id="insertUser" parameterType="User" useGeneratedKeys="true" keyProperty="id" >
insert into t_user(email,signtime)values(#{email},#{signtime})
</insert>
<!-- 方式二 獲取剛剛插入的自增主鍵id -->
<insert id="insertUserTwo" parameterType="User" useGeneratedKeys="true">
<selectKey resultType="java.lang.Integer" order="AFTER" keyProperty="id">
SELECT LAST_INSERT_ID()
</selectKey>
insert into t_user(email,signtime)values(#{email},#{signtime})
</insert>
<select id="findUser" resultType="User">
select * from t_user where id=#{id} and email=#{email}
</select>
</mapper>
TbUserMapper.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">
<!-- namespace 介面全名 -->
<mapper namespace="com.feifan.mapper.TbUserMapper">
<!-- statement -->
<select id="selectById" parameterType="int" resultType="TbUser" >
SELECT * FROM tb_user where id=#{id}
</select>
</mapper>
新增資料後，獲取自增主鍵的值：
方式1：
<!-- 通過useGeneratedKeys="true" keyProperty="id" 獲取剛剛插入的自增主鍵id, keyProperty="id
並把賦值給物件的屬性id
-->
<insert id="insertUser" parameterType="User" useGeneratedKeys="true" keyProperty="id" >
insert into t_user(email,signtime)values(#{email},#{signtime})
</insert>
方式二:
<!-- 方式二 獲取剛剛插入的自增主鍵id -->
<insert id="insertUserTwo" parameterType="User" useGeneratedKeys="true">
<selectKey resultType="java.lang.Integer" order="AFTER" keyProperty="id">
SELECT LAST_INSERT_ID()
</selectKey>
insert into t_user(email,signtime)values(#{email},#{signtime})
</insert>
測試類：
public class TestMybatis {
public static void main(String[] args) {
new TestMybatis().testSelectById();
new TestMybatis().insertGetId();
}
public void insertGetId(){
User user=new User();
/** 向資料庫中增加資料 */
SqlSession sqlSession3 = MybatisUtils.getSqlSession();
UserMapper userMapper3 = sqlSession3.getMapper(UserMapper.class);
user.setEmail("94201435");
user.setSigntime(new Date());
System.err.println(user);
userMapper3.insertUserTwo(user);
sqlSession3.commit();//預設事務關閉，需要手動提交事務
sqlSession3.close();
System.out.println(user.getId());
System.out.println();
}
@Test
public void testSelectById(){
//簡單工程log4j 屬性檔案 需要使用載入此屬性檔案
PropertyConfigurator.configure("src/main/resource/log4j.properties");
/**使用介面方式 查詢資料庫*/
SqlSession sqlSession = MybatisUtils.getSqlSession();
UserMapper userMapper = sqlSession.getMapper(UserMapper.class);
User user = userMapper.selectById(2);
System.out.println(user);
System.out.println();
/** 使用一般的方式查詢資料庫 名稱空間+方法名 ，引數*/
Object one = sqlSession.selectOne("com.feifan.mapper.UserMapper.selectById", 2);
System.out.println(((User)one).toString());
System.out.println();
/** 向資料庫中增加資料 */
SqlSession sqlSession3 = MybatisUtils.getSqlSession();
UserMapper userMapper3 = sqlSession3.getMapper(UserMapper.class);
user.setEmail("94201435");
user.setSigntime(new Date());
System.err.println(user);
userMapper3.insertUser(user);
sqlSession3.commit();//預設事務關閉，需要手動提交事務
System.out.println(user.getId());
System.out.println();
/** 多個引數傳遞 查詢*/
User findUser = userMapper.findUser(2, "9090");
System.out.println(findUser);
System.out.println();
/** 查詢另外一個表 */
SqlSession sqlSession2 = MybatisUtils.getSqlSession();
TbUserMapper tbUserMapper = sqlSession.getMapper(TbUserMapper.class);
TbUser tbUser = tbUserMapper.selectById(2);
System.out.println(tbUser);
sqlSession.close();
sqlSession2.close();
}
}
輸出結果：
[email protected]
[email protected]
{
CreateTime:"2018-11-10 18:04:50",
ActiveCount:0,
PoolingCount:0,
CreateCount:0,
DestroyCount:0,
CloseCount:0,
ConnectCount:0,
Connections:[
]
}
2018-11-10 18:04:50 2018-11-10 18:04:50,782 INFO [com.alibaba.druid.pool.DruidDataSource] -{dataSource-1} inited
Sat Nov 10 18:04:50 CST 2018 WARN: Establishing SSL connection without server's identity verification is n