SSM框架之mybatis极速入门！

安装

pom.xml部分(maven导入依赖)

 <build>
        <!--设置版本-->
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>14</source>
                    <target>14</target>
                </configuration>
            </plugin>
        </plugins>
      <resources>
		  <resource>
		  <directory>src/main/resources</directory>
		  <includes> <include>**/*.properties</include>
		   <include>**/*.xml</include> </includes>
		   <filtering>true</filtering>
			</resource>
			 <resource>
				 <directory>src/main/java</directory>
				 <includes> <include>**/*.properties</include>
				 <include>**/*.xml</include> </includes>
				  <filtering>true</filtering> </resource>
			</resources>
    </build>
    <dependencies>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.2</version>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.48</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>
    </dependencies>

mybatis-config.xml（核心配置文件）

<?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>
     <settings>
        <setting name="logImpl" value="STDOUT_LOGGING"/>
    </settings>
    <!-- 数据库环境 -->
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="com.mysql.jdbc.Driver"/>
                <property name="url" value="jdbc:mysql://localhost:3306/apiserve?useSSL=true&amp;characterEncoding=UTF-8"/>
                <property name="username" value="root"/>
                <property name="password" value="root"/>
            </dataSource>
        </environment>
    </environments>
    <!-- 映射文件 -->
    <mappers>
        <mapper resource="UserMapper.xml" />
    </mappers>

</configuration>

工具类

package botao.util;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;

import java.io.IOException;
import java.io.InputStream;

/**
 * @author cbt28
 */
public class MybatisUtils {
    private static SqlSessionFactory sqlSessionFactory;
    static {
        try {
            String resources="mybatis.xml";
            InputStream io = Resources.getResourceAsStream(resources);
            sqlSessionFactory = new SqlSessionFactoryBuilder().build(io);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    public static SqlSession getSqlSession(){
        return sqlSessionFactory.openSession();
    }
}

映射文件

<?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="botao.dao.UserMapper">
    <select id="findById" resultType="botao.pojo.User" parameterType="int">
        select * from  user where id=#{id}
    </select>
</mapper>