SSM框架整合(Spring+SpringMVC+MyBatis)及相关开发笔记

Spring+SpringMVC+MyBatis框架整合开发笔记，以下为SSM框架的简单案例代码及开发流程

 

配置pom.xml,通过Maven注入SSM需要的相关依赖

 <dependencies>
        <!--Junit-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.13.2</version>
            <scope>test</scope>
        </dependency>
        <!--数据库驱动-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.25</version>
        </dependency>

        <!--数据库连接池，c3p0-->
        <dependency>
            <groupId>com.mchange</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.5.5</version>
        </dependency>

        <!--Servlet相关-->
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>servlet-api</artifactId>
            <version>2.5</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet.jsp</groupId>
            <artifactId>jsp-api</artifactId>
            <version>2.2</version>
        </dependency>
        <dependency>
            <groupId>javax.servlet</groupId>
            <artifactId>jstl</artifactId>
            <version>1.2</version>
        </dependency>

        <!--MyBatis相关-->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.5.9</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>2.0.6</version>
        </dependency>

        <!--Spring相关-->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-webmvc</artifactId>
            <version>5.3.14</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>5.3.14</version>
        </dependency>
        <dependency>
            <groupId>org.aspectj</groupId>
            <artifactId>aspectjweaver</artifactId>
            <version>1.9.7</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-tx</artifactId>
            <version>5.3.14</version>
        </dependency>

        <!--lombok-->
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <version>1.18.22</version>
        </dependency>
    
    </dependencies>

加上xml文件资源过滤，防止xml静态资源无法读取

<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>

配置完成pom.xml后，根据数据库编写相应的实体类就行了,如下使用lombok注解简化

@Data
@AllArgsConstructor
@NoArgsConstructor
@ToString
public class User{
    private int id;
    private String username;
}

DAO层

首先根据需求开发DAO层的接口，这里我简单的编写了一些常用的增删查改操作。

public interface UserMapper {
    
    int addUser(User user);
    
    //@Param("id")需与实体类和数据库中的字段相同
    int deleteUserById(@Param("id") int id);

    int updateUser(User user);

    User queryUserById(@Param("id") int id);

    User queryUserByName(@Param("username") String username);

    List<User> queryAllUsers();
  
}

编写其实现类

//这里继承SqlSessionDaoSupport实现sqlSessionFactory注入
public class UserMapperImpl extends SqlSessionDaoSupport implements UserMapper {

    @Override
    public int addUser(User user) {
        return getSqlSession().getMapper(UserMapper.class).addUser(user);
    }
    
    //...
}

编写MyBatis的mapper.xml

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

<!--命名空间设为对应的mapper接口-->
<mapper namespace="com.project.dao.UserMapper">
    
     <!--其中#{id},#{username}就是从Mapper中对应函数的参数获取的-->
    <insert id="addUser" parameterType="User">
        insert into User (id,username)
        values (#{id},#{username});
    </insert>

   <!--..........-->

    <!--这里使用CONCAT拼接SQL语句实现模糊查询-->
    <select id="queryUserByName" resultType="User">
        select *
        from User where username like CONCAT(CONCAT('%',#{username}),'%');
    </select>
</mapper>

配置database.properties数据库配置文件

#MySQL 8.0以上使用com.mysql.cj.jdbc.Driver，以下则使用com.mysql.jdbc.Driver
jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/project?useSSL=false&useUnicode=true&characterEncoding=UTF-8&serverTimezone=UTC
jdbc.username=root
jdbc.password=123456

配置MyBatis配置文件mybatis-config.xml

<?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>
    <typeAliases>
        <!--配置别名-->
        <package name="com.project.pojo"/>
    </typeAliases>
    <!--绑定Mapper，mapper路径为resources/dao层对应的包名路径-->
    <mappers>
        <mapper class="com.project.dao.UserMapper"/>
    </mappers>
</configuration>

配置DAO层的配置文件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/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">

    <!--数据库配置,路径指向database.properties-->
    <context:property-placeholder location="classpath:database.properties"/>

    <!--配置数据源，这里使用c3p0-->
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">

        <!--对应database.properties的配置-->
        <property name="driverClass" value="${jdbc.driver}"/>
        <property name="jdbcUrl" value="${jdbc.url}"/>
        <property name="user" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>

        <!--配置c3p0连接池大小-->
        <property name="maxPoolSize" value="30"/>
        <property name="minPoolSize" value="10"/>
        <!--关闭连接后不自动提交-->
        <property name="autoCommitOnClose" value="false"/>
        <!--连接超时时间设为10秒-->
        <property name="checkoutTimeout" value="10000"/>
        <!--连接失败重试次数为2次-->
        <property name="acquireRetryAttempts" value="2"/>
    </bean>

    <!--SqlSessionFactory配置-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">

        <!--数据源指向前面配置的dataSource-->
        <property name="dataSource" ref="dataSource"/>

        <!--绑定Mybatis的配置文件-->
        <property name="configLocation" value="classpath:mybatis-config.xml"/>

    </bean>
    <!--将UserMapper注册到Spring-->
    <bean id="UserMapper" class="com.project.dao.UserMapperImpl">
         <!--注入sqlSessionFactory-->
         <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
    </bean>
</beans>

Service层

先编写service层接口及其实现类，调用Dao层即可

@Service
public class UserServiceImpl implements UserService{

    private UserMapper userMapper;
    //Spring通过set注入mapper
    public void setUserMapper(UserMapper userMapper) {
        this.userMapper = userMapper;
    }

    @Override
    public int addUser(User user) {
        return userMapper.addUser(user);
    }
       
    //........
}

配置Service层配置文件spring-service.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:tx="http://www.springframework.org/schema/tx"
       xmlns:aop="http://www.springframework.org/schema/aop"
       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/tx
       http://www.springframework.org/schema/tx/spring-tx.xsd
       http://www.springframework.org/schema/aop
       https://www.springframework.org/schema/aop/spring-aop.xsd">
    
    <!--扫描Service包下的Service组件-->
    <context:component-scan base-package="com.project.service"/>
    <!--配置事务-->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <!--注入数据源-->
        <property name="dataSource" ref="dataSource"/>
    </bean>

    <!--注册service的bean-->
    <bean id="UserServiceImpl" class="com.project.service.UserServiceImpl">
        <!--SET注入Mapper-->
        <property name="UserMapper" ref="UserMapper"/>
    </bean>
</beans>

Controller层

编写controller, 首先注入service对象，然后根据需求编写需要的请求

@Controller
public class UserController {

    //自动装载service对象
    @Autowired
    @Qualifier("UserServiceImpl")
    private UserService userService;

    //请求路径
    @RequestMapping("/allUsers")
    public String getAllUsers(Model model){

        //调用service层，返回值通过Model传给前端
        model.addAttribute("allUsers",userService.queryAllUsers());

        //返回视图名给视图解析器
        return "allUsers";
    }

    //........

}

配置spring-controller.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/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/mvc
       http://www.springframework.org/schema/mvc/spring-mvc.xsd">
    
    <!--扫描包-->
    <context:component-scan base-package="com.project.controller"/>

    <!--静态资源过滤-->
    <mvc:default-servlet-handler/>

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

    <!--视图解析器-->
    <bean id="InternalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/"/>
        <property name="suffix" value=".jsp"/>
    </bean>

</beans>

整合三层架构配置文件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/beans
       http://www.springframework.org/schema/beans/spring-beans.xsd">

    <import resource="spring-controller.xml"/>
    <import resource="spring-service.xml"/>
    <import resource="spring-dao.xml"/>

</beans>

配置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">
    <!--配置DispatcherServlet-->
    <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:applicationContext.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>

    <!--配置乱码过滤器-->
    <filter>
        <filter-name>encodingFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>encodingFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

</web-app>