mybatis层要干的事情不多具体可以分为三块：
第一块：导入依赖，创建我们需要的类，先创建pojo类---->dao层建立Mapper类和对应的mapper的xml配置文件—>创建service层接口和对应的service层实现类去实现接口调用功能
第二块：这里主要是配置文件的书写，先写上mybatis-config.xml使用typeAliases给我们的mapper类开启重命名—>用mapper绑定上我们的dao层mapper的xml配置文件
第三块：编写我们spring层需要用到的数据库配置文件database.properties，编写applicationContext.xml，这个文件里面可以用import导入我需要的配置文件

第一步：导入依赖

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"><modelVersion>4.0.0</modelVersion><groupId>com.zsp</groupId><artifactId>ssmbuild1</artifactId><version>1.0-SNAPSHOT</version><dependencies><!--Junit--><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version></dependency><!--数据库驱动--><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.47</version></dependency><!-- 数据库连接池 --><dependency><groupId>com.mchange</groupId><artifactId>c3p0</artifactId><version>0.9.5.2</version></dependency><!--Servlet - JSP --><dependency><groupId>javax.servlet</groupId><artifactId>servlet-api</artifactId><version>2.5</version></dependency><dependency><groupId>javax.servlet.jsp</groupId><artifactId>jsp-api</artifactId><version>2.2</version></dependency><dependency><groupId>javax.servlet</groupId><artifactId>jstl</artifactId><version>1.2</version></dependency><!--Mybatis--><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.5.2</version></dependency><dependency><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId><version>2.0.2</version></dependency><!--Spring--><dependency><groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>5.1.9.RELEASE</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-jdbc</artifactId><version>5.1.9.RELEASE</version></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.12</version></dependency></dependencies></project>

这是pojo类：

package com.zsp.pojo;import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;@Data
@AllArgsConstructor
@NoArgsConstructor
public class Books {private int     bookID;private String bookName;private int bookCounts;private String detail;
}

我们需要的功能接口：

package com.zsp.dao;import com.zsp.pojo.Books;
import org.apache.ibatis.annotations.Param;import java.util.List;public interface BooksMapper {
//    增int addBook(Books books);
//    删int deleteBookById(@Param("bookID") int bookID );
//    改int updateBooks(Books books);
//    查List<Books> queryBooks();
}

功能接口的配置文件：

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE mapperPUBLIC "-//mybatis.org//DTD Mapper 3.0//EN""http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.zsp.dao.BooksMapper"><insert id="addBook" parameterType="books">insert  into books (bookName,bookCounts,detail)values(#{bookName},#{bookCounts},#{detail})</insert><delete id="deleteBookById" parameterType="_int">delete from books where bookId =#{bookId}</delete><update id="updateBooks" parameterType="books">update books<set><if test="bookName !=null">,bookName=#{bookName}</if><if test="bookCounts !=null">,bookCounts=#{bookCounts}</if><if test="detail !=null">,detail=#{detail}</if></set>where  bookId=#{bookId}</update><select id="queryBooks" resultType="books">select * from books</select></mapper>

第二步：
mybatis-config.xml的编写绑定上重命名和mapper文件：

<?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><typeAliases> <package name="com.zsp.pojo.Books"/></typeAliases><mappers><mapper resource="com/zsp/dao/BooksMapper.xml"></mapper></mappers>
</configuration>

第三步我们spring层要用到的applicationContext.xml：

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans.xsd"></beans>

我们一会用spring-dao连接数据库要用到的database.properties：

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/ssmbuild?useSSL=true&useUnicode=true&characterEncoding=utf8
jdbc.username=root
jdbc.password=123456