1、ssm整合原理
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
2、ssm整合步骤
2.1 创建MAVEN-web工程

替换掉web.xml文件
<?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"></web-app>
2.2 添加依赖
在pom.xml文件中添加依赖
<dependencies><!--spring-webmvc--><dependency><groupId>org.springframework</groupId><artifactId>spring-webmvc</artifactId><version>5.2.15.RELEASE</version></dependency><!--mybatis依赖--><dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.5.6</version></dependency><!--mybatis和spring整合的依赖--><dependency><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId><version>2.0.6</version></dependency><!--mysql驱动--><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>8.0.28</version></dependency><!--druid连接池依赖--><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.2.1</version></dependency><!--lombok依赖--><dependency><groupId>org.projectlombok</groupId><artifactId>lombok</artifactId><version>1.18.24</version></dependency><!--jackson java对象转换为json对象 @ResponseBody--><dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId><version>2.13.2.2</version></dependency><!--servlet-api依赖--><dependency><groupId>javax.servlet</groupId><artifactId>javax.servlet-api</artifactId><version>4.0.1</version></dependency><dependency><groupId>org.springframework</groupId><artifactId>spring-jdbc</artifactId><version>5.2.15.RELEASE</version></dependency><!--generator代码生成器--><dependency><groupId>org.mybatis.generator</groupId><artifactId>mybatis-generator-core</artifactId><version>1.4.0</version></dependency><!--sql日志--><dependency><groupId>log4j</groupId><artifactId>log4j</artifactId><version>1.2.17</version></dependency><dependency><groupId>org.slf4j</groupId><artifactId>slf4j-log4j12</artifactId><version>1.7.30</version></dependency></dependencies>
2.3 配置spring.xml文件
<?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/beans http://www.springframework.org/schema/beans/spring-beans.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd"><!--包扫描-->
<context:component-scan base-package="com.xsl" />
<!--静态资源放行-->
<mvc:default-servlet-handler />
<!--开启注解-->
<mvc:annotation-driven/><!--数据源配置-->
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"><property name="driverClassName" value="com.mysql.cj.jdbc.Driver"/><property name="url" value="jdbc:mysql://localhost:3306/mybatis?serverTimezone=Asia/Shanghai"/><property name="username" value="root"/><property name="password" value="123456"/><!--初始化连接数量:根据你项目的并发进行评估--><!--最少连接池的个数--><property name="minIdle" value="5"/><!--初始的连接池的个数--><property name="initialSize" value="5"/><!--最大的连接个数--><property name="maxActive" value="10"/><!--超过的最大连接池个数,等待时间 单位是毫秒--><property name="maxWait" value="3000"/>
</bean><bean id="sessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"><!--设置数据源--><property name="dataSource" ref="dataSource" /><!--设置mybatis映射文件的路径--><property name="mapperLocations" value="classpath:mapper/*.xml" />
</bean><!--为dao接口生成代理实现类-->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"><property name="basePackage" value="com.xsl.dao" />
</bean></beans>
2.4 配置web.xml文件
<?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"><!--servlet--><servlet><servlet-name>spring</servlet-name><servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class><init-param><param-name>contextConfigLocation</param-name><param-value>classpath:springmvc.xml</param-value></init-param></servlet><servlet-mapping><servlet-name>spring</servlet-name><url-pattern>/</url-pattern></servlet-mapping>
</web-app>
2.5 使用generator代码生成器
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfigurationPUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN""http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd"><generatorConfiguration>
<!--sql jar包在本地的位置--><classPathEntry location="D:\AAA\repMaven\mysql\mysql-connector-java\8.0.16\mysql-connector-java-8.0.16.jar" /><context id="DB2Tables" targetRuntime="MyBatis3"><!--取消全部解释--><commentGenerator><property name="suppressAllComments" value="true" /></commentGenerator><!--连接数据库--><jdbcConnection driverClass="com.mysql.cj.jdbc.Driver"connectionURL="jdbc:mysql://localhost:3306/mybatis?serverTimezone=Asia/Shanghai"userId="root"password="123456"></jdbcConnection><!--生成实体类的包--><javaModelGenerator targetPackage="com.xsl.entity" targetProject=".\src\main\java"><property name="enableSubPackages" value="true" /><property name="trimStrings" value="true" /></javaModelGenerator><!--生成mapper文件--><sqlMapGenerator targetPackage="mapper" targetProject=".\src\main\resources"><property name="enableSubPackages" value="true" /></sqlMapGenerator><!--生成dao包--><javaClientGenerator type="XMLMAPPER" targetPackage="com.xsl.dao" targetProject=".\src\main\java"><property name="enableSubPackages" value="true" /></javaClientGenerator><!--schema:所连接的数据库tableName:连接数据库的表名--><table schema="mybatis" tableName="tbl_user" domainObjectName="User"enableSelectByExample="false"enableCountByExample="false"enableDeleteByExample="false"enableUpdateByExample="false"><property name="useActualColumnNames" value="true"/><generatedKey column="ID" sqlStatement="DB2" identity="true" /><columnOverride column="DATE_FIELD" property="startDate" /><ignoreColumn column="FRED" /><columnOverride column="LONG_VARCHAR_FIELD" jdbcType="VARCHAR" /></table></context>
</generatorConfiguration>
2.6 添加sql日志文件
在resources中添加log4j.properties文件
log4j.rootLogger=DEBUG, Console
#Console
log4j.appender.Console=org.apache.log4j.ConsoleAppender
log4j.appender.Console.layout=org.apache.log4j.PatternLayout
log4j.appender.Console.layout.ConversionPattern=%d [%t] %-5p [%c] - %m%n
log4j.logger.java.sql.ResultSet=INFO
log4j.logger.org.apache=INFO
log4j.logger.java.sql.Connection=DEBUG
log4j.logger.java.sql.Statement=DEBUG
log4j.logger.java.sql.PreparedStatement=DEBUG
3、 添加controller层和serviceceng

在service中创建一个接口和一个类,这个类继承重写了接口的方法。
接口:
public interface UserService {public User findId(Integer userid);}
类:
@Service//注入依赖
public class UserServiceImpl implements UserService {@Autowired//自动注入public UserMapper userMapper;//重写接口的方法public User findId(Integer userid) {User user = userMapper.selectByPrimaryKey(userid);return user;}}
controller层
@RestController//相当于把数据转换成json数据
@RequestMapping("/user")
public class UserController {@Autowiredpublic UserService userService;@RequestMapping("getById")public User getById(Integer userid){User user = userService.findId(userid);return user;}
}


















