JDBC
1.导入pom.xml
<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>5.1.32</version>
</dependency>
<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.30</version>
</dependency>
2.编写JDBC代码
工具类:
package cn.tianshi.utils;
import org.apache.commons.dbcp2.BasicDataSource;
import java.io.IOException;
import java.io.InputStream;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Properties;
public class JDBCUtils {
// 加载驱动，并建立数据库连接
public static Connection getConnection() throws SQLException,
ClassNotFoundException, IOException {
InputStream in = JDBCUtils.class.getClassLoader().getResourceAsStream("jdbc.properties");
Properties properties = new Properties();
properties.load(in);
String driverClassName=properties.getProperty("driverClassName");
String url = properties.getProperty("url");
String username = properties.getProperty("username");
String password = properties.getProperty("password");
System.out.println(url+"djd"+username);
Class.forName(driverClassName);
// Class.forName("com.mysql.cj.jdbc.Driver");
// String url = "jdbc:mysql://localhost:3306/bookman?serverTimezone=GMT%2B8";
// String username = "root";
// String password = "root";
Connection conn = DriverManager.getConnection(url, username,password);
/*常见的开源数据库连接池：
DBCP：速度比C3P0快但有bug
c3p0:速度慢，但相对稳定
Proxool：开源连接池，有监控连接池的功能，但稳定性比C3P0差
BoneCP：速度快，开源
Druid：阿里提供的连接池，速度快(不及BoneCP)，稳定性好，有监控连接池的功能
1.DBCP
BasicDataSource dbs=new BasicDataSource();
dbs.setDriverClassName(driverClassName);
dbs.setUrl(url);
dbs.setUsername(username);
dbs.setPassword(password);
Connection conn=dbs.getConnection();
*/
return conn;
}
// 关闭数据库连接，释放资源
public static void release(Statement stmt, Connection conn) {
if (stmt != null) {
try {
stmt.close();
} catch (SQLException e) {
e.printStackTrace();
}
stmt = null;
}
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
conn = null;
}
}
public static void release(ResultSet rs, Statement stmt,
Connection conn){
if (rs != null) {
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
rs = null;
}
release(stmt, conn);
}
}
Mybatis
Mybatis + JDBC
1.导入pom文件
```xml
<!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
<dependency>
<groupId>org.mybatis</groupId>
<artifactId>mybatis</artifactId>
<version>3.5.6</version>
</dependency>
<!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.30</version>
</dependency>
2.Mapper.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="">
</mapper>
注:同时编写对应的接口文件
3.mybatis-config.xml
<?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>
<!--读取jdbc.properties属性-->
<properties resource="jdbc.properties"/>
<settings>
<!--设置日志输出-->
<!-- 设置查看 mybatis 生成的 sql 语句的日志配置-->
<setting name="logImpl" value="STDOUT_LOGGING"/>
<!--
是否开启驼峰命名自动映射，即从经典数据库列名 A_COLUMN 映射到经典 Java 属性名 aColumn。
-->
<setting name="mapUnderscoreToCamelCase" value="true"/>
</settings>
<!--注册实体类的别名-->
<typeAliases>
<package name="_实体类所在的包_"/>
</typeAliases>
<!--配置环境变量-->
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="${jdbc.driverClassName}"/>
<property name="url" value="${jdbc.url}"/>
<property name="username" value="${jdbc.username}"/>
<property name="password" value="${jdbc.password}"/>
</dataSource>
</environment>
</environments>
<mappers>
<!--批量注册 mapper.xml
name 为所有事的mapper.xml文件所在的包
在resources文件目录下新建 com/nfjh/mapper
此时不需要在pom.xml中设置资源文件扫描
-->
<package name="_mapper所在的包_"/>
</mappers>
</configuration>
4.jdbc.properties
jdbc.driverClassName=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:端口/数据库?useUnicode=true&characterEncoding=utf8&useSSL=true&serverTimezone=GMT%2B8
jdbc.username=root
jdbc.password=root
5.test.java
SqlSession sqlSession = null;
Mapper mapper = null;
//日期的格式化刷子
SimpleDateFormat sf = new SimpleDateFormat("yyyy-MM-dd");
@Before
public void openSession() throws IOException {
//1、创建资源流,读取核心配置文件
InputStream in = Resources.getResourceAsStream("核心配置文件");
//2、获取sql会话工厂
SqlSessionFactory build = new SqlSessionFactoryBuilder().build(in);
//3、获取sql会话对象
sqlSession = build.openSession();
//4、[取出动态代理对象]
mapper = sqlSession.getMapper(Mapper.class);
//5、执行操作
//6、[事务提交]
}
@After
public void closeSession(){
//7、关闭会话
sqlSession.close();
}
@Test
public void testUpdate() throws ParseException {
Users u = new Users(7,"haha66",sf.parse("2000-01-01"),"2","北京大兴亦庄66");
int num = uMapper.update(u);
System.out.println(num);
//切记切记切记:手工提交事务
sqlSession.commit();
}
Mybatis-plus
1.导入pom.xml文件
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>2.2.5.RELEASE</version>
</parent>
<!-- properties 标签位置 -->
<dependencies>
<!--Spring Web-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<!--Spring Test-->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<scope>test</scope>
</dependency>
<!--Mybatis-Plus-->
<!-- https://mvnrepository.com/artifact/com.baomidou/mybatis-plus-boot-starter -->
<dependency>
<groupId>com.baomidou</groupId>
<artifactId>mybatis-plus-boot-starter</artifactId>
<version>3.5.3.2</version>
</dependency>
<!--JDBC-->
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<!--druid数据源|连接池依赖-->
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid-spring-boot-starter</artifactId>
<version>1.1.10</version>
</dependency>
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.2.8</version>
</dependency>
</dependencies>
<build>
<plugins>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
</plugins>
<!--文件夹映射-->
<resources>
<resource>
<directory>src/main/java</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
<include>**/*.yml</include>
<include>**/*.yaml</include>
</includes>
<filtering>false</filtering>
</resource>
<resource>
<directory>src/main/resources</directory>
<includes>
<include>**/*.properties</include>
<include>**/*.xml</include>
<include>**/*.yml</include>
<include>**/*.yaml</include>
</includes>
<filtering>false</filtering>
</resource>
</resources>
</build>
<!-- 通过添加文件映射解决yaml文件查找不到,解决驱动查找失败,连接数据库失败的问题-->
2.yaml文件(yml文件)
要保证添加的文件yaml/yml文件的后缀在pom中已经添加了映射
环境
如果在非springboot的环境下使用Mybatis
Spring
<?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">
<!--或者SqlMapConfig.xml-->
<configuration>
<settings>
<!-- 设置查看 mybatis 生成的 sql 语句的日志配置-->
<setting name="logImpl" value="STDOUT_LOGGING"/>
<!--
是否开启驼峰命名自动映射，即从经典数据库列名 A_COLUMN 映射到经典 Java 属性名 aColumn。
-->
<setting name="mapUnderscoreToCamelCase" value="true"/>
</settings>
<!--
<mappers>
<package name=""></package>
</mappers>
-->
</configuration>
---
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