环境：

• IDEA 2019
• MySQL 8
• Tomcat 9
• Maven 3.6

Navicat 创建0project_ssm_firstbuild数据库的books表

CREATE TABLE `books` (
`bookID` INT(10) NOT NULL AUTO_INCREMENT COMMENT '书id',
`bookName` VARCHAR(100) NOT NULL COMMENT '书名',
`bookCounts` INT(11) NOT NULL COMMENT '数量',
`detail` VARCHAR(200) NOT NULL COMMENT '描述',
KEY `bookID` (`bookID`)
) ENGINE=INNODB DEFAULT CHARSET=utf8INSERT  INTO `books`(`bookID`,`bookName`,`bookCounts`,`detail`)VALUES 
(1,'Java',1,'从入门到放弃'),
(2,'MySQL',10,'从删库到跑路'),
(3,'Linux',5,'从进门到进牢');

基本环境搭建

1.创建一个空的maven项目0first_ssmbuild

2.添加ssmbuild.pom依赖 和 静态资源过滤

    <!-- 集中定义依赖版本号 --><properties><!-- 单元测试 --><junit.version>4.12</junit.version><!--快速编写javabean--><lombok.version>1.18.10</lombok.version><!-- JSP相关 --><jstl.version>1.2</jstl.version><standard.version>1.1.2</standard.version><servlet-api.version>2.5</servlet-api.version><jsp-api.version>2.0</jsp-api.version><!--!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!--></properties><dependencies><!-- 单元测试 --><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>${junit.version}</version></dependency><!--快速编写javabean--><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>${lombok.version}</version></dependency><!-- JSP相关 --><dependency><groupId>jstl</groupId><artifactId>jstl</artifactId><version>${jstl.version}</version></dependency><dependency><groupId>taglibs</groupId><artifactId>standard</artifactId><version>${standard.version}</version></dependency><dependency><groupId>javax.servlet</groupId><artifactId>servlet-api</artifactId><version>${servlet-api.version}</version><scope>provided</scope></dependency><dependency><groupId>javax.servlet</groupId><artifactId>jsp-api</artifactId><version>${jsp-api.version}</version><scope>provided</scope></dependency><!--mysqlq驱动--><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.12</version></dependency><!-- 数据库连接池：c3p0 --><dependency><groupId>com.mchange</groupId><artifactId>c3p0</artifactId><version>0.9.5.2</version></dependency><!--！！！！！！！！！！！！！！！！！！！！！！！！-mybatis！！！！！！！！！！！！！！！！！！！！！！！！--><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.5.4</version></dependency><!--！！！！！！！！！！！！！！！！！！！！！！！！-spring相关！！！！！！！！！！！！！！！！！！！！！！！！--><dependency><groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>5.1.10.RELEASE</version></dependency><!--spring用来连接数据库--><dependency><groupId>org.springframework</groupId><artifactId>spring-jdbc</artifactId><version>5.1.10.RELEASE</version></dependency><!--AOP相关--><dependency><groupId>org.aspectj</groupId><artifactId>aspectjweaver</artifactId><version>1.9.4</version></dependency><!--mybatis-spring整合包--><dependency><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId><version>2.0.2</version></dependency><!--！！！！！！！！！！！！！！！！！！！！！！！！springMVC包，在spring中！！！！！！！！！！！！！！！！！！！！！！！！--></dependencies><build><resources><resource><directory>src/main/java</directory><includes><include>**/*.properties</include><include>**/*.xml</include></includes><filtering>false</filtering></resource><resource><directory>src/main/resources</directory><includes><include>**/*.properties</include><include>**/*.xml</include></includes><filtering>false</filtering></resource></resources></build>

3.建立基本结构和配置框架

• mybatis-config.xml

  <?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></configuration>
  

• 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>
  

在 applicationContext.xml 中点击上面的黄色

Mybatis层编写

1.在resources目录下，编写数据库配置文件：database.properties

jdbc.driver=com.mysql.jdbc.Driver
#如果使用的是MySQL8.0+，增加一个时区的配置:&serverTimezone=Asia/Shanghai
#ssmbuild是我要连接的数据库
jdbc.url=jdbc:mysql://localhost:3306/ssmbuild?useSSL=true&useUnicode=true&characterEncoding=utf8&serverTimezone=Asia/Shanghai
jdbc.username=root
jdbc.password=5位

2.IDEA关联数据库：连接数据库,并测试是否连接到books表

参考我的博客：IDEA关联数据库（在界面的右边的Database）

3. 在mybatis-config.xml下，编写核心配置

   <typeAliases><package name="com.kuang.pojo"/></typeAliases><mappers><mapper resource="com/kuang/dao/BookMapper.xml"/></mappers>

4. 编写数据库对应的实体类 com.kuang.pojo.Books

如果上面没有get，set就要安装下面的插件，如果成功，则忽略这个步骤

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Books {   private int bookID;private String bookName;private int bookCounts;private String detail; 
}

5. 编写Dao层的 Mapper接口：BookMapper

public interface BookMapper {//增加一个Bookint addBook(Books book);//根据id删除一个Bookint deleteBookById(int id);//更新Bookint updateBook(Books books);//根据id查询,返回一个BookBooks queryBookById(int id);//查询全部Book,返回list集合List<Books> queryAllBook();
}

6. 编写接口对应的 BookMapper.xml 文件

右边是：BookMapper.java文件

namespace=“com.kuang.dao.BookMapper” 不要错了

<?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.kuang.dao.BookMapper"><!--增加一个Book--><insert id="addBook" parameterType="Books">insert into books(bookName,bookCounts,detail)values (#{bookName}, #{bookCounts}, #{detail})</insert><!--根据id删除一个Book--><delete id="deleteBookById" parameterType="int">delete from books where bookID=#{id}</delete><!--更新Book--><update id="updateBook" parameterType="Books">update booksset bookName = #{bookName},bookCounts = #{bookCounts},detail = #{detail}where bookID = #{bookID}</update><!--根据id查询,返回一个Book--><select id="queryBookById" resultType="Books">select * from books where bookID = #{id}</select><!--查询全部Book--><select id="queryAllBook" resultType="Books">SELECT * from books</select></mapper>

在 mybatis-config.xml 注册

    <mappers><mapper resource="com/kuang/dao/BookMapper.xml"/></mappers>

7. 编写Service层的接口：BookService 和实现类：BookServiceImpl

接口：BookService ：

//BookService:底下需要去实现,调用dao层
public interface BookService {//增加一个Bookint addBook(Books book);//根据id删除一个Bookint deleteBookById(int id);//更新Bookint updateBook(Books books);//根据id查询,返回一个BookBooks queryBookById(int id);//查询全部Book,返回list集合List<Books> queryAllBook();
}

实现类：BookServiceImpl：

public class BookServiceImpl implements BookService {//serviceidao层：组合Dao//调用dao层的操作，设置一个set接口，方便Spring管理private BookMapper bookMapper;public void setBookMapper(BookMapper bookMapper) {this.bookMapper = bookMapper;}public int addBook(Books book) {return bookMapper.addBook(book);}public int deleteBookById(int id) {return bookMapper.deleteBookById(id);}public int updateBook(Books books) {return bookMapper.updateBook(books);}public Books queryBookById(int id) {return bookMapper.queryBookById(id);}public List<Books> queryAllBook() {return bookMapper.queryAllBook();}
}

OK，到此，底层需求操作编写完毕！

Spring层编写

1、Spring整合MyBatis:---->相关的配置文件spring-dao.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"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/contexthttps://www.springframework.org/schema/context/spring-context.xsd"><!-- 配置整合mybatis --><!-- 1.关联数据库文件 --><context:property-placeholder location="classpath:database.properties"/><!-- 2.数据库连接池 --><!--数据库连接池dbcp 半自动化操作 不能自动连接c3p0 自动化操作（自动的加载配置文件 并且设置到对象里面）--><bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"><!-- 配置连接池属性 --><property name="driverClass" value="${jdbc.driver}"/><property name="jdbcUrl" value="${jdbc.url}"/><property name="user" value="${jdbc.username}"/><property name="password" value="${jdbc.password}"/><!-- c3p0连接池的私有属性 --><property name="maxPoolSize" value="30"/><property name="minPoolSize" value="10"/><!-- 关闭连接后不自动commit --><property name="autoCommitOnClose" value="false"/><!-- 获取连接超时时间 --><property name="checkoutTimeout" value="10000"/><!-- 当获取连接失败重试次数 --><property name="acquireRetryAttempts" value="2"/></bean><!-- 3.配置SqlSessionFactory对象 --><bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"><!-- 注入数据库连接池 --><property name="dataSource" ref="dataSource"/><!-- 配置MyBaties全局配置文件:mybatis-config.xml --><property name="configLocation" value="classpath:mybatis-config.xml"/></bean><!-- 4.配置扫描Dao接口包，动态实现Dao接口注入到spring容器中 --><!--解释 ：https://www.cnblogs.com/jpfss/p/7799806.html--><bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"><!-- 注入sqlSessionFactory --><property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/><!-- 给出需要扫描Dao接口包 --><property name="basePackage" value="com.kuang.dao"/></bean>
</beans>

2. Spring整合service层:---->相关的配置文件spring-service.xml

configure后，红色消失

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xmlns:context="http://www.springframework.org/schema/context"xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context.xsd"><!-- 扫描service相关的bean --><context:component-scan base-package="com.kuang.service" /><!--BookServiceImpl注入到IOC容器中--><bean id="BookServiceImpl" class="com.kuang.service.BookServiceImpl"><property name="bookMapper" ref="bookMapper"/></bean><!-- 配置事务管理器 --><bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"><!-- 注入数据库连接池 --><property name="dataSource" ref="dataSource" /></bean></beans>

Spring层搞定！再次理解一下，Spring就是一个大杂烩，一个容器！对吧！

SpringMVC层编写

1. 添加web内核，编写web.xml

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"version="4.0"><!--DispatcherServlet--><servlet><servlet-name>DispatcherServlet</servlet-name><servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class><init-param><param-name>contextConfigLocation</param-name><!--一定要注意:我们这里加载的是总的配置文件，之前被这里坑了！-->  <param-value>classpath:applicationContext.xml</param-value></init-param><load-on-startup>1</load-on-startup></servlet><servlet-mapping><servlet-name>DispatcherServlet</servlet-name><url-pattern>/</url-pattern></servlet-mapping><!--encodingFilter--><filter><filter-name>encodingFilter</filter-name><filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class><init-param><param-name>encoding</param-name><param-value>utf-8</param-value></init-param></filter><filter-mapping><filter-name>encodingFilter</filter-name><url-pattern>/*</url-pattern></filter-mapping><!--Session过期时间--><session-config><session-timeout>15</session-timeout></session-config></web-app>

2. 编写 spring-mvc.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"xmlns:context="http://www.springframework.org/schema/context"xmlns:mvc="http://www.springframework.org/schema/mvc"xsi:schemaLocation="http://www.springframework.org/schema/beanshttp://www.springframework.org/schema/beans/spring-beans.xsdhttp://www.springframework.org/schema/contexthttp://www.springframework.org/schema/context/spring-context.xsdhttp://www.springframework.org/schema/mvchttps://www.springframework.org/schema/mvc/spring-mvc.xsd"><!-- 配置SpringMVC --><!-- 1.开启SpringMVC注解驱动 --><mvc:annotation-driven /><!-- 2.静态资源默认servlet配置--><mvc:default-servlet-handler/><!-- 3.配置jsp 显示ViewResolver视图解析器 --><bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"><property name="viewClass" value="org.springframework.web.servlet.view.JstlView" /><property name="prefix" value="/WEB-INF/jsp/" /><property name="suffix" value=".jsp" /></bean><!-- 4.扫描web相关的bean --><context:component-scan base-package="com.kuang.controller" /></beans>

3. Spring配置整合文件，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"><import resource="spring-dao.xml"/><import resource="spring-service.xml"/><import resource="spring-mvc.xml"/></beans>

最终项目结构：