一：原理

1.springmvc：
1）.客户端发送请求到DispacherServlet（分发器）

2）.由DispacherServlet控制器查询HanderMapping，找到处理请求的Controller

3）.Controller调用业务逻辑处理后，返回ModelAndView

4）.DispacherSerclet查询视图解析器，找到ModelAndView指定的视图

5）.视图负责将结果显示到客户端

2.spring

平时开发接触最多的估计就是IOC容器，它可以装载bean（也就是我们Java中的类，当然也包括service dao里面的），有了这个机制，我们就不用在每次使用这个类的时候为它初始化，很少看到关键字new。另外spring的aop，事务管理等等都是我们经常用到的。

3.Mybatis

mybatis是对jdbc的封装，它让数据库底层操作变的透明。mybatis的操作都是围绕一个sqlSessionFactory实例展开的。mybatis通过配置文件关联到各实体类的Mapper文件，Mapper文件中配置了每个类对数据库所需进行的sql语句映射。在每次与数据库交互时，通过sqlSessionFactory拿到一个sqlSession，再执行sql命令。

4.各项作用：

SSM框架是spring MVC ，spring和mybatis框架的整合，是标准的MVC模式，将整个系统划分为表现层，controller层，service层，DAO层四层

使用spring MVC负责请求的转发和视图管理

spring实现业务对象管理，mybatis作为数据对象的持久化引擎

二：开发流程

1.新建maven项目

2.配置整合文件

2.1 配置pom.xml文件—引入依赖

 <properties><project.spring.version>5.3.9</project.spring.version></properties><dependencies><dependency><groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>${project.spring.version}</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-orm</artifactId><version>${project.spring.version}</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-test</artifactId><version>${project.spring.version}</version><scope>test</scope></dependency><!-- mybatis --><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.5.7</version></dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.25</version></dependency><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.2.6</version></dependency><dependency><groupId>log4j</groupId><artifactId>log4j</artifactId><version>1.2.17</version></dependency><dependency><groupId>org.slf4j</groupId><artifactId>slf4j-api</artifactId><version>1.7.32</version></dependency><dependency><groupId>org.slf4j</groupId><artifactId>slf4j-log4j12</artifactId><version>1.7.32</version></dependency><dependency><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId><version>2.0.6</version></dependency><dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.12</version><scope>test</scope></dependency><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.20</version></dependency><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId><version>2.12.4</version></dependency></dependencies>

2.2 配置web.xml文件

 <context-param><param-name>contextConfigLocation</param-name><param-value>classpath:spring/mybatis/spring-*.xml</param-value></context-param><!-- 启动业务loc容器 --><listener><listener-class>org.springframework.web.context.ContextLoaderListener</listener-class></listener><!-- 启动mvc容器 --><servlet><servlet-name>springDispatcherServlet</servlet-name><servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class><init-param><param-name>contextConfigLocation</param-name><!-- springmvc文件位置 --><param-value>classpath:spring/mvc/springmvc-*.xml</param-value></init-param><load-on-startup>1</load-on-startup></servlet><servlet-mapping><servlet-name>springDispatcherServlet</servlet-name><url-pattern>/*</url-pattern></servlet-mapping>

2.3 配置springmvc

  <!-- 扫描位置 --><context:component-scan base-package="com.dyit.ssm.entity"/><!-- 静态资源放行 --><mvc:resources location="static/" mapping="static/**"/><!-- 驱动注解 --><mvc:annotation-driven/>

2.4 配置mybatis

1).配置spring-mybatis.xml

   <!-- 管理范围 --><context:component-scan base-package="com.dyit.ssm"><context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>      </context:component-scan><context:property-placeholder location="classpath:spring/mybatis/druid/druid.properties"/><!-- 数据源 --><bean id="dataSource"class="com.alibaba.druid.pool.DruidDataSource"><property name="url" value="${druid.url}" /><property name="username" value="${druid.username}" /><property name="password" value="${druid.password}" /><property name="driverClassName" value="${druid.driver}" /></bean><!-- 容器创建SqlSessionFactory --><bean id="sqlSessionFactory"class="org.mybatis.spring.SqlSessionFactoryBean"><property name="dataSource" ref="dataSource" /><property name="typeAliasesPackage" value="com.dyit.ssm.entity"/><property name="mapperLocations" value="classpath:spring/mybatis/mapper/*.mapper.xml"/></bean><!-- 配置接口 --><bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"><property name="basePackage" value="com.dyit.ssm.mapper"/><property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/></bean><!-- 事务 --><bean id="txManger" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"><property name="dataSource" ref="dataSource"/></bean><!-- 让spring管理起来 --><tx:annotation-driven transaction-manager="txManger"/>

2）.配置druid.properties 数据源（数据库相关配置）

druid.url=jdbc:mysql://192.168.1.8:3306/book_db?useSSL=false&serverTimezone=Asia/Shanghai&allowPublicKeyRetrieval=true
druid.username=root
druid.password=12345
druid.driver=com.mysql.cj.jdbc.Driver

3.配置Book.mapper.xml（数据库的映射类）

在此我以数据库的 增删改查 为例

<mapper namespace="com.dyit.ssm.mapper.IBookMapper"><sql id="findAllBook">SELECT * FROM book_tab</sql><resultMap type="Book" id="BookMap"><id property="id" column="book_id" /><result property="title" column="book_title" /><result property="price" column="book_price" /><result property="author" column="book_author" /></resultMap><insert id="save">INSERT INTO book_tab(book_title,book_author,book_price)VALUES(#{title},#{author},#{price})</insert><delete id="deleteById">DELETE FROM book_tab WHERE book_id=#{id}</delete><insert id="update">UPDATE book_tab SET book_title=#{title},book_author=#{author},book_price=#{price}WHERE book_id=#{id}</insert><select id="findAll" resultMap="BookMap"><include refid="findAllBook" /></select></mapper>

3.java代码—测试

1）写实体类

@Alias("Book")  //别名
@Data
@AllArgsConstructor
@NoArgsConstructor
public class Book {private Integer id; //idprivate String title;  //书名private double price;  //价格private String author;  //作者}

2）写mapper类–对数据库的操作接口

@Mapper
public interface IBookMapper {void save(Book book);  //添加void deleteById(int id); //根据id删除void update(Book book); //修改List<Book> findAll(); //全查询
}

3）写service接口

public interface IBookService {void save(Book book);  //添加void deleteById(int id); //根据id删除void update(Book book); //修改List<Book> findAll();}

4）写service接口的实现类

@Service
public class BookServiceImpl implements IBookService{@Autowiredprivate IBookMapper mapper; //注入mapper@Overridepublic void save(Book book) { mapper.save(book);}@Overridepublic void deleteById(int id) {mapper.deleteById(id);}@Overridepublic void update(Book book) {mapper.update(book);}@Overridepublic List<Book> findAll() {return mapper.findAll();}}

5）写service测试类

@RunWith(SpringJUnit4ClassRunner.class) //测试注解
@ContextConfiguration(locations = "classpath:spring/mybatis/spring-mybatis.xml") //控制文件路径
public class ssmTest {@Autowiredprivate IBookService ibs;  //注入service@Testpublic void testSave() {  //添加ibs.save(new Book(4, "西游外传", 66.66, "孙悟空"));}@Testpublic void testDeleteById() {  //删除ibs.deleteById(2);;}@Testpublic void testUpdate() {  //修改ibs.save(new Book(4, "西游前传", 88.66, "唐三藏"));}@Testpublic void testFindAll() {  //全查询System.out.println(ibs.findAll());}}

6.以添加图书为例查看测试结果展示

注：因没有写日志配置类，故报红

成功添加进数据库