整合 SSM

<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-context</artifactId>
    <version>5.2.8.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>5.2.8.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-tx</artifactId>
    <version>5.2.8.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-web</artifactId>
    <version>5.2.8.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-webmvc</artifactId>
    <version>5.2.8.RELEASE</version>
</dependency>
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.5.5</version>
</dependency>
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis-spring</artifactId>
    <version>2.0.5</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>5.1.6</version>
</dependency>
<dependency>
    <groupId>com.mchange</groupId>
    <artifactId>c3p0</artifactId>
    <version>0.9.5.2</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-databind</artifactId>
    <version>2.9.5</version>
</dependency>
<dependency>
    <groupId>com.fasterxml.jackson.core</groupId>
    <artifactId>jackson-annotations</artifactId>
    <version>2.9.5</version>
</dependency>

<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:tx="http://www.springframework.org/schema/tx"
       xsi:schemaLocation="
        http://www.springframework.org/schema/context
        http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/tx
        http://www.springframework.org/schema/tx/spring-tx.xsd
        http://www.springframework.org/schema/beans
        http://www.springframework.org/schema/beans/spring-beans.xsd">

    <!-- 开启组件扫描 -->
    <context:component-scan base-package="com.software.ssm" >
        <!-- 排除 controller 的扫描 -->
        <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>

    <!-- 加载 propeties 文件 -->
    <context:property-placeholder location="classpath:mysql.properties"></context:property-placeholder>

    <!-- 配置数据源信息 -->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${mysql.driver}"></property>
        <property name="jdbcUrl" value="${mysql.url}"></property>
        <property name="user" value="${mysql.username}"></property>
        <property name="password" value="${mysql.password}"></property>
    </bean>

    <!-- 配置 sessionFactory -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"></property>
        <!-- 加载 mybatis 核心文件-->
        <property name="configLocation" value="classpath:mybatis.xml"></property>
    </bean>

    <!-- 扫描 mapper 所在的包 为 mapper 创建实现类-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.software.ssm.mapper"></property>
    </bean>


    <!-- 声明式事务控制 -->
    <tx:annotation-driven/>

    <!-- 引入 mvc 配置 -->
    <import resource="springmvc.xml" />

</beans>

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

    <!-- 组件扫描  主要扫描 controller -->
    <context:component-scan base-package="com.software.ssm.controller"></context:component-scan>

    <!-- 配置 mvc 注解驱动 -->
    <mvc:annotation-driven></mvc:annotation-driven>
</beans>

<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd">
<configuration>

    <!--定义别名-->
    <typeAliases>
        <package name="com.software.ssm.entity"></package>
    </typeAliases>

</configuration>

mysql.driver=com.mysql.jdbc.Driver
mysql.url=jdbc:mysql://localhost:3306/db
mysql.username=root
mysql.password=root

<!DOCTYPE web-app PUBLIC
        "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
        "http://java.sun.com/dtd/web-app_2_3.dtd" >
<web-app>
    <!--spring 监听器-->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:application.xml</param-value>
    </context-param>
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <!--springmvc的前端控制器-->
    <servlet>
        <servlet-name>DispatcherServlet</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>
        <load-on-startup>1</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>DispatcherServlet</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
</web-app>

public class Student {
    private Long id;
    private String name;
    private Integer age;
    
    // set and get
}

/**
 * Created with IntelliJ IDEA.
 *
 * @author Demo_Null
 * @date 2020/9/9
 * @description 数据访问层
 */
@Repository
public interface StudentMapper {
    @Select("select * from student")
    List<Student> findAll();
}

/**
 * Created with IntelliJ IDEA.
 *
 * @author Demo_Null
 * @date 2020/9/9
 * @description 服务层
 */
@Service
public class StudentService {

    @Autowired
    private StudentMapper studentMapper;

    public Object findAll() {
        return studentMapper.findAll();
    }
}

/**
 * Created with IntelliJ IDEA.
 *
 * @author Demo_Null
 * @date 2020/9/9
 * @description 控制器
 */
@RestController
@RequestMapping("/student")
public class StudentController {

    @Autowired
    private StudentService studentService;

    @GetMapping("/findAll")
    public Object findAll() {
        return studentService.findAll();
    }
}