SSM框架搭建

SSM整合

SSM是Spring + SpringMVC + Mybatis。虽然SpringBoot很火，但这一套SSM依然有很多公司是在使用的。下面我们来看看如何完整的配置一套SSM框架。

整合目标：

• 数据库连接池以及事务管理都交给Spring容器来完成
• SqlSessionFactory对象应该放到Spring容器中作为单例对象管理
• Mapper动态代理对象交给Spring管理，我们从Spring容器中直接获得Mapper的代理对象

整合需要的jar包：

• Junit测试jar（4.12版本）
• Mybatis的jar（3.4.5）
• Spring相关jar（spring-context、spring-test、spring-jdbc、spring-tx、spring-aop、
  aspectjweaver）
• Mybatis/Spring整合包jar（mybatis-spring-xx.jar）
• Mysql数据库驱动jar
• Druid数据库连接池的jar

1. 引入相关依赖

<dependencies>
        <!--junit-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
            <scope>test</scope>
        </dependency>
        <!--mybatis-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.4.5</version>
        </dependency>
        <!--spring相关-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>5.1.12.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>5.1.12.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.1.12.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>5.1.12.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-aop</artifactId>
            <version>5.1.12.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.8.9</version>
        </dependency>
        <!--mybatis与spring的整合包-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.3</version>
        </dependency>
        <!--数据库驱动jar-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.13</version>
        </dependency>
        <!--druid连接池-->
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.21</version>
        </dependency>
    </dependencies>

2. Spring配置文件-dao层相关

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:tx="http://www.springframework.org/schema/tx"
       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/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
">
    <!--包扫描-->
    <context:component-scan base-package="com.mmc.ssm.mapper"/>
    <!--数据库连接池以及事务管理都交给Spring容器来完成-->
    <!--引⼊外部资源⽂件-->
    <context:property-placeholder
            location="classpath:jdbc.properties"/>
    <!--第三⽅jar中的bean定义在xml中-->
    <bean id="dataSource"
          class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="${jdbc.driver}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>
    <!--SqlSessionFactory对象应该放到Spring容器中作为单例对象管理
    原来mybaits中sqlSessionFactory的构建是需要素材的：SqlMapConfig.xml中的内
    容
    -->
    <bean id="sqlSessionFactory"
          class="org.mybatis.spring.SqlSessionFactoryBean">
        <!--别名映射扫描-->
        <property name="typeAliasesPackage" value="com.mmc.ssm.bean"/>
        <!--数据源dataSource-->
        <property name="dataSource" ref="dataSource"/>
        <property name="mapperLocations" value="classpath:mapper/*"></property>
    </bean>
    <!--Mapper动态代理对象交给Spring管理，我们从Spring容器中直接获得Mapper的代理对
    象-->
    <!--扫描mapper接⼝，⽣成代理对象，⽣成的代理对象会存储在ioc容器中-->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <!--mapper接⼝包路径配置-->
        <property name="basePackage" value="com.mmc.ssm.mapper"/>
        <property name="sqlSessionFactoryBeanName"
                  value="sqlSessionFactory"/>
    </bean>
</beans>

配置文件里还引入了jdbc的一个配置文件jdbc.properties
内容如下：

jdbc.driver=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://127.0.0.1:3306/test?useUnicode=true&characterEncoding=utf8&autoReconnect=true&allowMultiQueries=true&useSSL=false&serverTimezone=UTC
jdbc.username=root
jdbc.password=0490218292

3. Spring配置文件-service层相关

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:context="http://www.springframework.org/schema/context"
       xmlns:tx="http://www.springframework.org/schema/tx"
       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/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
">
    <!--包扫描-->
    <context:component-scan base-package="com.mmc.ssm.service.impl"/>
    <!--事务管理-->
    <bean id="transactionManager"
          class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>
    <!--事务管理注解驱动-->
    <tx:annotation-driven transaction-manager="transactionManager"/>
</beans>

4. 编写mapper接口

public interface UserMapper {

    List<User> queryUserList();
}

5. 编写mapper的xml文件

<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.mmc.ssm.mapper.UserMapper">
    <select id="queryUserList" resultType="com.mmc.ssm.bean.User">
      select * from user
    </select>
</mapper>

6. 到这里我们可以先测试一下之前的代码

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath*:applicationContext*.xml")
public class TestSSM {


    @Autowired
    private UserService userService;

    @Test
    public void test(){
        List<User> users = userService.queryUsers();
        System.out.println(users);
    }

}

没有问题了再继续整合SpringMVC
7. 引入SpringMVC 依赖

 <!--SpringMVC-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.1.12.RELEASE</version>
        </dependency>
        <!--jsp-api&servlet-api-->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.0</version>
            <scope>provided</scope>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>javax.servlet-api</artifactId>
            <version>3.1.0</version>
            <scope>provided</scope>
        </dependency>
        <!--⻚⾯使⽤jstl表达式-->
        <dependency>
            <groupId>jstl</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>
        <dependency>
            <groupId>taglibs</groupId>
            <artifactId>standard</artifactId>
            <version>1.1.2</version>
        </dependency>
        <!--json数据交互所需jar，start-->
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-core</artifactId>
            <version>2.9.0</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-databind</artifactId>
            <version>2.9.0</version>
        </dependency>
        <dependency>
            <groupId>com.fasterxml.jackson.core</groupId>
            <artifactId>jackson-annotations</artifactId>
            <version>2.9.0</version>
        </dependency>
        <!--json数据交互所需jar，end-->

8. 配置Spring MVC配置文件

<?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:mvc="http://www.springframework.org/schema/mvc"
       xmlns:context="http://www.springframework.org/schema/context"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/mvc
        https://www.springframework.org/schema/mvc/spring-mvc.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd">
    <!--扫描controller-->
    <context:component-scan base-package="com.mmc.ssm.controller"/>
    <mvc:annotation-driven/>
</beans>

9. 编写contrller类

@Controller
public class UserController {

    @Autowired
    private UserService userService;

    @RequestMapping("/listUser")
    @ResponseBody
    public List<User> listUser(){
      return  userService.queryUsers();
    }

}

10. 配置SpringMVC及Spring容器启动

<!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>

    <display-name>Archetype Created Web Application</display-name>'

    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:applicationContext*.xml</param-value>
    </context-param>
    <!--spring框架启动-->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>


    <!--springmvc启动-->
    <servlet>
        <servlet-name>springmvc</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>springmvc</servlet-name>
        <url-pattern>/</url-pattern>
    </servlet-mapping>
</web-app>

11. 启动项目

在项目的pom.xml里加入

war

再加入maven启动插件：

 <build>
        <plugins>
            <plugin>
                <groupId>org.apache.tomcat.maven</groupId>
                <artifactId>tomcat7-maven-plugin</artifactId>
                <version>2.2</version>
                <configuration>
                    <port>8080</port>
                    <path>/</path>
                </configuration>
            </plugin>
        </plugins>
    </build>

就可以点击tomcat7:run启动了。

项目整体结构如下：

需要注意：
Spring容器和SpringMVC容器是有层次的。
Spring容器里配置了Service和dao对象，SpringMVC容器里有controller对象，它可以引用Spring容器里的对象。但是Spring容器不能引用SpringMVC里的对象。

SpringMVC里是要配置controller的，如果Spring再配置的话，就是两个容器里都有controller对象，且两个对象是不同的。