Data Access 之 MyBatis（六）- Spring、Spring MVC、MyBatis整合

整合Spring & Spring MVC & MyBatis

1.建工程

创建一个Maven工程ssm，分别在pom.xml文件中导入Spring、Spring MVC以及MyBatis的相关依赖

<properties>
    <spring-version>5.3.13</spring-version>
</properties>

<dependencies>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-beans</artifactId>
        <version>${spring-version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>${spring-version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-test</artifactId>
        <version>${spring-version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-aop</artifactId>
        <version>${spring-version}</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-aspects</artifactId>
        <version>${spring-version}</version>
    </dependency>
    <dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.12</version>
        <scope>test</scope>
    </dependency>
    <dependency>
        <groupId>commons-logging</groupId>
        <artifactId>commons-logging</artifactId>
        <version>1.2</version>
    </dependency>
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>${spring-version}</version>
    </dependency>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>javax.servlet-api</artifactId>
        <version>3.1.0</version>
        <scope>provided</scope>
    </dependency>
    <!-- https://mvnrepository.com/artifact/javax.servlet.jsp.jstl/jstl -->
    <dependency>
        <groupId>javax.servlet.jsp.jstl</groupId>
        <artifactId>jstl</artifactId>
        <version>1.2</version>
    </dependency>

    <!--spring jdbc依赖-->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>${spring-version}</version>
    </dependency>
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>8.0.16</version>
    </dependency>
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid</artifactId>
        <version>1.1.14</version>
    </dependency>

    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.5.7</version>
    </dependency>

    <dependency>
        <groupId>ch.qos.logback</groupId>
        <artifactId>logback-classic</artifactId>
        <version>1.2.3</version>
    </dependency>
    <dependency>
        <groupId>org.projectlombok</groupId>
        <artifactId>lombok</artifactId>
        <version>1.16.18</version>
        <scope>provided</scope>
    </dependency>
</dependencies>

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添加Web Application，勾选创建web.xml

Data Access 之 MyBatis（六）- Spring、Spring MVC、MyBatis整合

2.写配置

2.1 web.xml的配置

对一个Web应用来说，首先要配置web.xml，其中配置了Spring配置文件的路径、Spring MVC前端控制器配置文件的路径以及解决乱码和Rest请求的过滤器

<?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">

    <!--Spring-->
    <context-param>
        <param-name>contextConfigLocation</param-name>
        <param-value>classpath:application.xml</param-value>
    </context-param>
    <!--缺少监听器的话在Tomcat启动时会报错创建Bean失败-->
    <listener>
        <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

    <!--DispatchServlet-->
    <servlet>
        <servlet-name>dispatcherServlet</servlet-name>
        <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
        <load-on-startup>0</load-on-startup>
    </servlet>
    <servlet-mapping>
        <servlet-name>dispatcherServlet</servlet-name>
        <!--"/" 代表拦截所有请求,/*拦截所有请求包括jsp页面这些请求-->
        <url-pattern>/</url-pattern>
    </servlet-mapping>

    <!--解决POST请求中文乱码问题-->
    <filter>
        <filter-name>characterFilter</filter-name>
        <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
        <init-param>
            <param-name>encoding</param-name>
            <param-value>UTF-8</param-value>
        </init-param>
    </filter>
    <filter-mapping>
        <filter-name>characterFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

    <!--Rest支持-->
    <filter>
        <filter-name>hiddenHttpMethodFilter</filter-name>
        <filter-class>org.springframework.web.filter.HiddenHttpMethodFilter</filter-class>
    </filter>
    <filter-mapping>
        <filter-name>hiddenHttpMethodFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

</web-app>

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2.2 Spring MVC的配置

在WEB-INF目录下新建dispatcherServlet-servlet.xml，这个位置是Spring MVC会默认查找的路径，文件名也是Spring MVC默认的查找名即配置的DispatcherServlet名称-serverlt.xml，所以在web.xml中的servlet-class标签下并没有配置Spring MVC配置文件的路径，使用的是默认的路径和默认的名称。在dispatcherServlet-servlert.xml中先后配置扫描cotroller包、视图解析器、静态资源和动态资源扫描的配置

<?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:util="http://www.springframework.org/schema/util"
       xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context"
       xmlns:aop="http://www.springframework.org/schema/aop" xmlns:mvc="http://www.springframework.org/schema/mvc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/util
        http://www.springframework.org/schema/util/spring-util-4.3.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/aop https://www.springframework.org/schema/aop/spring-aop.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <context:component-scan base-package="com.citi" use-default-filters="false">
        <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>

    <!--配置试图解析器，自动拼接页面地址，自动在jsp页面前增加/WEB-INF/pages/-->
    <bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/pages/"></property>
        <property name="suffix" value=".jsp"></property>
    </bean>

    <!-- 默认前端控制器是拦截所有资源（除过jsp），js文件就404了；要js文件的请求是交给tomcat处理的
http://localhost:8080/7.SpringMVC_crud/scripts/jquery-1.9.1.min.js -->
    <!-- 告诉SpringMVC，自己映射的请求就自己处理，不能处理的请求直接交给tomcat -->
    <!-- 静态资源能访问，动态映射的请求就不行 -->
    <mvc:default-servlet-handler/>
    <!-- springmvc可以保证动态请求和静态请求都能访问 -->
    <mvc:annotation-driven></mvc:annotation-driven>
</beans>

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2.3 Spring 的配置

在resources目录下新建application.xml作为Spring的配置，主要包括以下几个配置

配置包扫描
配置数据源
配置声明式事务

<?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:util="http://www.springframework.org/schema/util"
       xmlns:p="http://www.springframework.org/schema/p" xmlns:context="http://www.springframework.org/schema/context"
       xmlns:tx="http://www.springframework.org/schema/tx" xmlns:jdbc="http://www.springframework.org/schema/jdbc"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/util
        http://www.springframework.org/schema/util/spring-util-4.3.xsd http://www.springframework.org/schema/context https://www.springframework.org/schema/context/spring-context.xsd http://www.alibaba.com/schema/stat http://www.alibaba.com/schema/stat.xsd http://www.springframework.org/schema/tool http://www.springframework.org/schema/tool/spring-tool.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd http://www.springframework.org/schema/jdbc http://www.springframework.org/schema/jdbc/spring-jdbc.xsd">

    <!--扫描除了控制器之前的其他包-->
    <context:component-scan base-package="com.citi">
        <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
    </context:component-scan>
    <!--引用外部配置文件-->
    <context:property-placeholder location="classpath:db.properties"></context:property-placeholder>

    <!--数据库连接池配置-->
    <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}"/>
        <property name="initialSize" value="${jdbc_initialSize}"/>
        <property name="maxActive" value="${jdbc_maxActive}"/>
    </bean>

    <!--事务管理器配置-->
    <bean id="dataSourceTransactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"></property>
    </bean>
    <!--开启基于注解的配置模式-->
    <tx:annotation-driven transaction-manager="dataSourceTransactionManager" />

</beans>

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db.properties配置了数据库连接的相关信息

jdbc_driver=com.mysql.cj.jdbc.Driver
jdbc_url=jdbc:mysql://localhost:3306/test?useUnicode=true&amp;characterEncoding=utf8&amp;autoReconnect=true&amp;useSSL=false&amp;serverTimezone=Asia/Shanghai
jdbc_username=root
jdbc_password=root
jdbc_initialSize=10
jdbc_maxActive=20

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2.4 MyBatis的配置

配置MyBatis全局配置文件mybatis-config.xml，只配置settings标签就可以，数据源、mapper等配置在Spring配置文件application.xml中设置。

<?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>

    <settings>
        <!--开启驼峰命名-->
        <setting name="mapUnderscoreToCamelCase" value="true"/>
        <!--开启懒加载-->
        <setting name="lazyLoadingEnabled" value="true"/>
        <setting name="aggressiveLazyLoading" value="false"/>
        <!--开启二级缓存-->
        <setting name="cacheEnabled" value="true"/>
    </settings>
</configuration>

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在Spring配置文件application.xml中将Myabtis整合到Spring中，需要先导入Mybatis-Spring的依赖

<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis-spring</artifactId>
    <version>2.0.7</version>
</dependency>

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在application.xml中增加SqlSessionFactoryBean配置

<bean id="sqlSessionFactoryBean" class="org.mybatis.spring.SqlSessionFactoryBean">
    <property name="configLocation" value="mybatis-config.xml"></property>
    <property name="dataSource" ref="dataSource"></property>
    <property name="mapperLocations" value="classpath:/mappers/*.xml"></property>
</bean>

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将mapper包下的Mapper接口全部加入到Spring容器中

<!--持久层接口加入到Spring容器-->
<bean id="mapperScannerConfigurer" class="org.mybatis.spring.mapper.MapperScannerConfigurer">
    <!--指定接口所在的包-->
    <property name="basePackage" value="com.citi.mapper"></property>
</bean>

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2.5 其他配置

mybatis日志配置logback.xml，放在resource目录下。可以在控制台打印出SQL

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
   <appender name="console" class="ch.qos.logback.core.ConsoleAppender">
       <encoder>
           <pattern>[%thread] %d{HH:mm:ss.SSS} %-5level %logger{36} - %msg%n</pattern>
       </encoder>
   </appender>
    <root level="debug">
        <appender-ref ref="console"/>
    </root>
</configuration>

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至此Spring、Spring MVC、MyBatis三个框架整合完成

3.测试

持久层Mapper接口测试

数据库表与上一篇QA 由浅入深持久层框架（七）- MyBatis Cache用到的是同一张表，即t_teacher，这里不再重复

新建entity包，增加Teacher实体类

@Data
public class Teacher implements Serializable {

    private Integer id;
    private String teacherName;
    private String className;
    private String address;
    private Date birthDate;
}

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新建mapper包，增加TeacherMapper接口，并增加一个根据id查询Teahcer的方法

public interface TeacherMapper {

    Teacher getTeacherById(Integer id);
}

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在resources目录下新增mappers文件夹，用来存放Mapper接口的SQL映射文件，新建TeacherMapper接口的SQL映射文件TeacherMapper.xml

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

    <!--开启二级缓存-->
    <cache></cache>

    <select id="getTeacherById" resultType="com.citi.entity.Teacher">
        select * from t_teacher where id = #{id}
    </select>
</mapper>

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在test包下新增TeacherMapper接口的测试类TeacherMapperTest，新增getTeacherById方法的测试方法

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:application.xml")
public class TeacherMapperTest {

    @Autowired
    private TeacherMapper teacherMapper;

    @Test
    public void getTeacherById() {

        teacherMapper.getTeacherById(1);
    }
}

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测试类中用到了Spring Test，主要不要忘记类上的两个注解

执行测试方法

成功查询到了id为2的Teacher对象

Service层测试

新建service包，在该包下新增TeacherService接口，新增一个根据id查找Teacher的方法

public interface TeacherService {

    Teacher findTeacherById(Integer id);
}

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在service包下新增impl包，用来保存接口的实现类，在impl包中新增TeacherService接口的实现类TeacherServiceImpl

@Service
public class TeacherServiceImpl implements TeacherService {

    @Autowired
    private TeacherMapper teacherMapper;

    @Override
    public Teacher findTeacherById(Integer id) {
        return teacherMapper.getTeacherById(id);
    }
}

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增加TeacherService的测试类TeacherServiceTest

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "classpath:application.xml")
public class TeacherServiceTest {

    @Autowired
    private TeacherService teacherService;

    @Test
    public void findTeacherById() {

        Teacher teacher = teacherService.findTeacherById(1);
        System.out.println(teacher);
    }
}

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执行测试

控制台成功输出id为1的Teacher对象，说明service层调用mapper层成功

Controller层测试

配置Tomcat前，首先选中项目，点击IDEA菜单的File选项，点击Project Structure，左边选择Artifacts，在WEB-INF下新建一个lib目录，将右侧的jar包全部选中并导入lib文件夹中

配置Tomcat，点击IDEA的DEIT Configurations，配置一个本地的Tomcat

并将项目部署到Tomcat中

编写Controller层代码，新建controller包，增加TeacherController类

@Controller
@RequestMapping("/teacher")
public class TeacherController {

    @Resource
    public TeacherService teacherService;

    @RequestMapping("/{id}")
    public ModelAndView findTeacher(@PathVariable("id") Integer id){

        Teacher teacher = teacherService.findTeacherById(id);
        ModelAndView modelAndView = new ModelAndView();
        modelAndView.addObject("teacher",teacher);
        modelAndView.setViewName("success");
        return modelAndView;
    }

}

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视图解析器已经配置了WEB-INF下的pages目录，所以在WEB-INF下新增pages目录并新增一个jsp文件success.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
    <h2>SUCCESS</h2>
    <h3>${teacher}</h3>
</body>
</html>

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启动Tomcat，浏览器输入地址http://localhost:8080/teacher/1，查询id为1的Teacher的信息

Spring、Spring MVC、MyBatis整合成功！