Mybatis 整合流程

① 添加MyBatis的依赖
② 创建数据库表
③ 编写pojo实体类
④ 编写映射文件UserMapper.xml
⑤ 编写核心文件mybatis-config.xml
⑥ 编写测试类**

编写 pojo 实体类 (设计相应的数据库）

@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {private int id;  //idprivate String name;   //姓名private String pwd;   //密码
}

UserMapper 接口实现

List<User> getUserLike(String value);//查询全部用户
List<User> findAll();//根据id查询用户
User selectUserById(int id);
User getUserById(Map<String,Object> map);// 万能的map//添加一个用户
int addUser(User user);
int addUser2(Map<String,Object> map);// 万能的map//修改一个用户
int updateUser(User user);//删除一个用户
int deleteUser(int id);// 分页List<User> Limit(Map<String,Integer> map);List<User> RowBounds();

UserMapper.xml （dao包下面）

<!--查询操作<select id="findAll" resultType="com.hp.pojo.User"> 下面同理可见--><!--模糊查询--><select id="getUserLike" resultType="User">select *from user where pwd like "%"#{value}"%"</select><!--查询全部操作--><select id="findAll" resultType="user">select * from user</select><!--插入操作--><insert id="addUser" parameterType="user">insert into user values(#{id},#{username},#{password})</insert><!--万能的 Map 操作--><insert id="addUser2" parameterType="map">insert into user values (#{userid1111},#{userName},#{password})</insert><!--删除操作--><delete id="delete" parameterType="int">delete from user where id=#{id}</delete><!--修改操作--><update id="update" parameterType="user">update user set username=#{username},password=#{password} where id=#{id}</update><!--根据id进行查询--><select id="findById" resultType="user" parameterType="int">select * from user where id=#{id}</select><!--分页 结果集映射--><resultMap id="UserMap" type="User"/><select id="Limit" parameterType="map" resultMap="UserMap">select * from user limit #{startIndex},#{pageSize}</select><!--分页 方法2--><select id="RowBounds" resultType="User">select * from user</select>

mybatis-config.xml （Resources资源目录下）

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configurationPUBLIC "-//mybatis.org//DTD Config 3.0//EN""http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration><!--通过properties标签加载外部properties文件--><properties resource="db.properties"/><!--引入日志工厂--><settings><setting name="logImpl" value="STDOUT_LOGGING"/></settings><!-- 设置驼峰命名规则--><settings><setting name="mapUnderscoreToCamelCase" value="true"/></settings><!--自定义别名--><typeAliases><typeAlias type="com.hp.pojo.User" alias="user"/></typeAliases><!--数据源环境--><environments default="mysql"><environment id="mysql"><transactionManager type="JDBC"/><dataSource type="POOLED"><property name="driver" value="${jdbc.driver}"/><property name="url" value="${jdbc.url}"/><property name="username" value="${jdbc.username}"/><property name="password" value="${jdbc.password}"/></dataSource></environment></environments><!--加载映射文件--><mappers><!--告诉 mybatis 要执行的 sql 语句的位置  引入外部xml文件--><mapper resource="com/hp/dao/mapper.xml"/></mappers></configuration>

抽出 MyBatisUtil 工具类 简化测试代码（Util包下面）

public class MyBatisUtil {//定义 SqlSessionFactoryprivate static SqlSessionFactory factory = null;static {//使用 静态块 创建一次 SqlSessionFactorytry {//读取配置文件InputStream inputStream = Resources.getResourceAsStream("mybatis-config.xml");//创建 SqlSessionFactory 对象factory = new SqlSessionFactoryBuilder().build(inputStream);} catch (Exception e) {factory = null;e.printStackTrace();}}/* 获取 SqlSession 对象 */public static SqlSession getSqlSession() {SqlSession sqlsession = null;if (factory != null) {sqlsession = factory.openSession();}return sqlsession;}
}

测试类代码

public void findAll() {SqlSession sqlSession = MyBatisUtil.getSqlSession();UserMapper mapper = sqlSession.getMapper(UserMapper.class);List<User> userList = mapper.findAll();// userList.forEach(System.out::println); 也可以遍历全部输出for (User user : userList) {  // 增强for循环输出System.out.println(user);}sqlSession.close();}

db.properties

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/mybatis?useSSL=true&useUnicode=true&characterEncoding=utf8
jdbc.username=root
jdbc.password=root

log4j.properties

log4j.rootLogger=DEBUG,console,file#控制台输出的相关设置
log4j.appender.console = org.apache.log4j.ConsoleAppender
log4j.appender.console.Target = System.out
log4j.appender.console.Threshold=DEBUG
log4j.appender.console.layout = org.apache.log4j.PatternLayout
log4j.appender.console.layout.ConversionPattern=[%c]-%m%n#文件输出的相关设置
log4j.appender.file = org.apache.log4j.RollingFileAppender
log4j.appender.file.File=./log/hp.log
log4j.appender.file.MaxFileSize=10mb
log4j.appender.file.Threshold=DEBUG
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=[%p][%d{yy-MM-dd}][%c]%m%n#日志输出级别
log4j.logger.org.mybatis=DEBUG
log4j.logger.java.sql=DEBUG
log4j.logger.java.sql.Statement=DEBUG
log4j.logger.java.sql.ResultSet=DEBUG
log4j.logger.java.sql.PreparedStatement=DEBUG

Maven 依赖配置

<dependencies><!--mybatis-spring --><dependency><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId><version>2.0.2</version></dependency><!--junit --><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version><scope>test</scope></dependency><!-- mybatis --><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.5.9</version></dependency><!-- mysql-connector-java --><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.9</version></dependency><!-- spring-webmvc --><dependency><groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>5.1.9.RELEASE</version></dependency><!-- spring-jdbc --><dependency><groupId>org.springframework</groupId><artifactId>spring-jdbc</artifactId><version>5.1.9.RELEASE</version></dependency><!-- lombok --><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.16.10</version><scope>provided</scope></dependency></dependencies><!-- Maven静态资源过滤问题--><build><resources><resource><directory>src/main/java</directory><!--所在的目录--><includes><!--包括目录下的.properties,.xml 文件都会扫描到--><include>**/*.properties</include><include>**/*.xml</include></includes><filtering>false</filtering></resource></resources><plugins><plugin><artifactId>maven-compiler-plugin</artifactId><version>3.1</version><configuration><source>1.8</source><target>1.8</target></configuration></plugin></plugins></build>