一、导入依赖

  1. <!--依赖-->
  2. <dependencies>
  3.     <!-- pagehelper:分页插件 -->
  4.     <dependency>
  5.         <groupId>com.github.pagehelper</groupId>
  6.         <artifactId>pagehelper</artifactId>
  7.         <version>5.1.10</version>
  8.     </dependency>
  10.     <!--Junit-->
  11.     <dependency>
  12.         <groupId>junit</groupId>
  13.         <artifactId>junit</artifactId>
  14.         <version>4.12</version>
  15.     </dependency>
  16.     <!--mysql jdbc数据库驱动-->
  17.     <dependency>
  18.         <groupId>mysql</groupId>
  19.         <artifactId>mysql-connector-java</artifactId>
  20.         <version>5.1.47</version>
  21.     </dependency>
  22.     <!-- 数据库连接池 -->
  23.     <dependency>
  24.         <groupId>com.alibaba</groupId>
  25.         <artifactId>druid</artifactId>
  26.         <version>1.1.16</version>
  27.     </dependency>
  29.     <!--Servlet支持-->
  30.     <dependency>
  31.         <groupId>javax.servlet</groupId>
  32.         <artifactId>servlet-api</artifactId>
  33.         <version>2.5</version>
  34.     </dependency>
  35.     <!--jsp-api-->
  36.     <dependency>
  37.         <groupId>javax.servlet.jsp</groupId>
  38.         <artifactId>jsp-api</artifactId>
  39.         <version>2.2</version>
  40.     </dependency>
  41.     <!--添加jstl支持-->
  42.     <dependency>
  43.         <groupId>javax.servlet</groupId>
  44.         <artifactId>jstl</artifactId>
  45.         <version>1.1.2</version>
  46.     </dependency>
  47.     <dependency>
  48.         <groupId>taglibs</groupId>
  49.         <artifactId>standard</artifactId>
  50.         <version>1.1.2</version>
  51.     </dependency>
  53.     <!--Spring 支持-->
  54.     <dependency>
  55.         <groupId>org.springframework</groupId>
  56.         <artifactId>spring-core</artifactId>
  57.         <version>5.2.12.RELEASE</version>
  58.     </dependency>
  59.     <dependency>
  60.         <groupId>org.springframework</groupId>
  61.         <artifactId>spring-beans</artifactId>
  62.         <version>5.2.12.RELEASE</version>
  63.     </dependency>
  64.     <dependency>
  65.         <groupId>org.springframework</groupId>
  66.         <artifactId>spring-context</artifactId>
  67.         <version>5.2.12.RELEASE</version>
  68.     </dependency>
  69.     <dependency>
  70.         <groupId>org.springframework</groupId>
  71.         <artifactId>spring-context-support</artifactId>
  72.         <version>5.2.12.RELEASE</version>
  73.     </dependency>
  74.     <dependency>
  75.         <groupId>org.springframework</groupId>
  76.         <artifactId>spring-web</artifactId>
  77.         <version>5.2.12.RELEASE</version>
  78.     </dependency>
  79.     <!--Spring mcv支持-->
  80.     <dependency>
  81.         <groupId>org.springframework</groupId>
  82.         <artifactId>spring-webmvc</artifactId>
  83.         <version>5.1.9.RELEASE</version>
  84.     </dependency>
  86.     <!--Mybatis-->
  87.     <dependency>
  88.         <groupId>org.mybatis</groupId>
  89.         <artifactId>mybatis</artifactId>
  90.         <version>3.4.5</version>
  91.     </dependency>
  92.     <dependency>
  93.         <groupId>org.mybatis</groupId>
  94.         <artifactId>mybatis-spring</artifactId>
  95.         <version>1.3.2</version>
  96.     </dependency>
  97.     <!--spring jdbc支持-->
  98.     <dependency>
  99.         <groupId>org.springframework</groupId>
  100.         <artifactId>spring-jdbc</artifactId>
  101.         <version>5.1.9.RELEASE</version>
  102.     </dependency>
  104.     <dependency>
  105.         <groupId>org.projectlombok</groupId>
  106.         <artifactId>lombok</artifactId>
  107.         <version>1.18.24</version>
  108.     </dependency>
  110.     <!--spring aop编程支持-->
  111.     <dependency>
  112.         <groupId>org.aspectj</groupId>
  113.         <artifactId>aspectjweaver</artifactId>
  114.         <version>1.6.8</version>
  115.     </dependency>
  116.     <dependency>
  117.         <groupId>org.springframework</groupId>
  118.         <artifactId>spring-aop</artifactId>
  119.         <version>5.2.12.RELEASE</version>
  120.     </dependency>
  122. </dependencies>
  124. <!--资源为加载进去，加入下列代码-->
  125. <build>
  126.     <resources>
  127.         <resource>
  128.             <directory>src/main/resources</directory>
  129.             <includes>
  130.                 <!--按需求添加-->
  131.                 <include>**/*.xml</include>
  132.                 <include>**/*.properties</include>
  133.             </includes>
  134.             <filtering>true</filtering>
  135.         </resource>
  136.         <resource>
  137.             <directory>src/main/java</directory>
  138.             <includes>
  139.                 <!--按需求添加-->
  140.                 <include>**/*.xml</include>
  141.                 <include>**/*.properties</include>
  142.             </includes>
  143.             <filtering>true</filtering>
  144.         </resource>
  145.     </resources>
  146. </build>

二、编写逻辑代码

1、编写实体类Admin

2、编写映射接口mapper文件夹（也可以是dao文件夹，看个人习惯）

  1. public interface AdminMapper {
  2.     // 根据id查询用户
  3.     Admin selectById(Integer id);
  4. }

3、编写AdminMapper.xml

注意：

  1. 方式一：可以放在资源目录下（一般把xml文件放在mapper），然后编写映射配置
  3. 方式二：我这里在mapper文件夹下创建xml，用来存放xml文件
  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
  3.         "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
  4. <mapper namespace="com.shuai.mapper.AdminMapper">
  6.     <select id="selectById" parameterType="java.lang.Integer" resultType="Admin">
  7.         select * from admin where id = #{id,jdbcType=INTEGER}
  8.     </select>
  9. </mapper>

强调：扫描的接口一定要写对，不然调试会找不到，这是个大坑，单词一定要看清楚

4、编写service层(AdminService)去调dao层

  1. public interface AdminService {
  2.     // 根据id查询
  3.     Admin queryAdminById(Integer id);
  4. }

5、编写service层的实现类（我放在service文件夹下的impl下）AdminServiceImpl

  1. @Service("adminService")    // 注入到bean中
  2. public class AdminServiceImpl implements AdminService {
  4.     @Autowired
  5.     private AdminMapper adminMapper;
  7.     public Admin queryAdminById(Integer id) {
  8.         return adminMapper.selectById(id);
  9.     }
  10. }

6、最后，通过Controller层调用返回给页面（AdminController）

  1. @Controller
  2. public class AdminController {
  4.     @Autowired
  5.     private AdminService adminService;
  7.     @GetMapping("/admin")
  8.     public String list(Model model){
  9.         Admin admin = adminService.queryAdminById(1);
  10.         model.addAttribute("list",admin);
  11.         return "query";
  12.     }
  13. }

三、核心配置

1、db.properties

  1. jdbc.driver=com.mysql.jdbc.Driver
  2. jdbc.url=jdbc:mysql://localhost:3306/library_system?useUnicode=true&characterEncoding=utf8&useSSL=true&serverTimezone=UTC
  3. jdbc.username=root
  4. jdbc.password=shuai

2、mybatis-config.xml

  1. <?xml version="1.0" encoding="UTF-8" ?>
  2. <!DOCTYPE configuration
  3.         PUBLIC "-//mybatis.org//DTD Config 3.0//EN"
  4.         "http://mybatis.org/dtd/mybatis-3-config.dtd">
  5. <configuration>
  7.     <!-- 全局配置 -->
  8.     <settings>
  9.         <!--允许 JDBC 支持自动生成主键-->
  10.         <setting name="useGeneratedKeys" value="false"/>
  11.         <!--是否开启自动驼峰命名规则（camel case）映射，即从经典数据库列名 A_COLUMN 到经典
  12.             Java 属性名 aColumn 的类似映射。 -->
  13.         <setting name="mapUnderscoreToCamelCase" value="true"/>
  15.         <!-- 打印查询语句 -->
  16.         <!--        <setting name="logImpl" value="STDOUT_LOGGING" />-->
  17.     </settings>
  20.     <plugins>
  21.         <plugin interceptor="com.github.pagehelper.PageInterceptor">
  22.             <!--<property name="dialect" value="mysql"/>-->
  23.             <!--<property name="offsetAsPageNum" value="false"/>-->
  24.             <!--<property name="rowBoundsWithCount" value="false"/>-->
  25.             <!--<property name="pageSizeZero" value="true"/>-->
  26.             <property name="reasonable" value="true"/>
  27.             <!--<property name="supportMethodsArguments" value="false"/>-->
  28.             <!--<property name="returnPageInfo" value="none"/>-->
  29.         </plugin>
  30.     </plugins>
  32. </configuration>

3、spring-mybatis.xml

  1. <?xml version="1.0" encoding="UTF-8" ?>
  2. <beans xmlns="http://www.springframework.org/schema/beans"
  3.        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  4.        xmlns:context="http://www.springframework.org/schema/context"
  5.        xsi:schemaLocation="http://www.springframework.org/schema/beans
  6.         http://www.springframework.org/schema/beans/spring-beans.xsd
  7.         http://www.springframework.org/schema/context
  8.         http://www.springframework.org/schema/context/spring-context.xsd">
  10.     <!--开启注解支持-->
  11.     <context:annotation-config/>
  12.     <!--关联数据库文件-->
  13.     <context:property-placeholder location="classpath:db.properties"/>
  14.     <!--配置 Druid连接池-->
  15.     <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">
  16.         <property name="driverClassName" value="${jdbc.driver}"/>
  17.         <property name="url" value="${jdbc.url}"/>
  18.         <property name="username" value="${jdbc.username}"/>
  19.         <property name="password" value="${jdbc.password}"/>
  21.         <!-- 配置初始化大小、最小、最大 -->
  22.         <property name="initialSize" value="5" />
  23.         <property name="minIdle" value="2" />
  24.         <property name="maxActive" value="20" />
  26.         <!-- 配置获取连接等待超时的时间 -->
  27.         <property name="maxWait" value="60000" />
  29.         <!-- 配置间隔多久才进行一次检测，检测需要关闭的空闲连接，单位是毫秒 -->
  30.         <property name="timeBetweenEvictionRunsMillis" value="60000" />
  32.         <!-- 配置一个连接在池中最小生存的时间，单位是毫秒 -->
  33.         <property name="minEvictableIdleTimeMillis" value="300000" />
  35.         <property name="validationQuery" value="SELECT 'x'" />
  36.         <property name="testWhileIdle" value="true" />
  37.         <property name="testOnBorrow" value="false" />
  38.         <property name="testOnReturn" value="false" />
  40.         <!-- 打开PSCache，并且指定每个连接上PSCache的大小 -->
  41.         <property name="poolPreparedStatements" value="true" />
  42.         <property name="maxPoolPreparedStatementPerConnectionSize" value="20" />
  44.         <!-- 配置监控统计拦截的filters，去掉后监控界面sql无法统计 -->
  45.         <property name="filters" value="stat" />
  46.     </bean>
  48.     <!--创建sqlSessionFactory ==》 mybatis核心配置文件的读取-->
  49.     <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
  50.         <!--注入连接池-->
  51.         <property name="dataSource" ref="dataSource"/>
  52.         <!--加载mybatis全局配置文件-->
  53.         <property name="configLocation" value="classpath:mybatis-config.xml"/>
  54.         <!--mapper.xml所在位置-->
  55.         <property name="mapperLocations" value="classpath:com/shuai/mapper/xml/*.xml"/>
  56.         <!--指定需要使用别名的实体类-->
  57.         <property name="typeAliasesPackage" value="com.shuai.pojo"/>
  59.     </bean>
  61.     <!-- 扫描mybatis的mapper接口路径 -->
  62.     <!-- 这个bean可以把我们的mapper接口直接扫描到. 直接把接口扫描完. 注册到spring的bean中 -->
  63.     <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
  64.         <!--给出需要扫描的Dao接口-->
  65.         <property name="basePackage" value="com.shuai.mapper"/>
  66.         <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
  67.     </bean>
  69.     <!--配置声明式事务-->
  70.     <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
  71.         <!--连接数据库连接池-->
  72.         <property name="dataSource" ref="dataSource"/>
  73.     </bean>
  75. </beans>

4、spring-mvc.xml

  1. <?xml version="1.0" encoding="UTF-8" ?>
  2. <beans xmlns="http://www.springframework.org/schema/beans"
  3.        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  4.        xmlns:context="http://www.springframework.org/schema/context"
  5.        xmlns:mvc="http://www.springframework.org/schema/mvc"
  6.        xsi:schemaLocation="http://www.springframework.org/schema/beans
  7.         http://www.springframework.org/schema/beans/spring-beans.xsd
  8.         http://www.springframework.org/schema/context
  9.         http://www.springframework.org/schema/context/spring-context.xsd
  10.         http://www.springframework.org/schema/mvc
  11.         http://www.springframework.org/schema/mvc/spring-mvc.xsd">
  13.     <!-- 开启注解扫描 -->
  14.     <context:component-scan base-package="com.shuai"/>
  15.     <!--开启SpringMvc注解-->
  16.     <mvc:annotation-driven/>
  18.     <!--3.配置jsp 显示ViewResolver视图解析器-->
  19.     <bean id="internalResourceViewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
  20.         <property name="prefix" value="/WEB-INF/pages/"/>
  21.         <property name="suffix" value=".jsp"/>
  22.     </bean>
  24.     <!--过滤静态资源-->
  25.     <mvc:default-servlet-handler/>
  27. </beans>

5、web.xml

  1. <?xml version="1.0" encoding="UTF-8"?>
  2. <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee"
  3.          xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  4.          xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd"
  5.          version="4.0">
  7.     <!--配置DispatcherServlet：这个是SpringMvc核心：请求分发器，前端控制器-->
  8.     <servlet>
  9.         <servlet-name>DispatcherServlet</servlet-name>
  10.         <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
  11.         <!--声明配置文件位置-->
  12.         <init-param>
  13.             <param-name>contextConfigLocation</param-name>
  14.             <param-value>classpath:spring-mvc.xml</param-value>
  15.         </init-param>
  16.         <!--启动级别：1  意思就是项目启动时就加载这个servlet-->
  17.         <load-on-startup>1</load-on-startup>
  18.     </servlet>
  21.     <!--
  22.         在SpringMvc中，/  /*
  23.         / : 只匹配所有的请求，不会去匹配jsp页面
  24.         /* : 匹配所有页面， 包括jsp页面
  25.     -->
  26.     <servlet-mapping>
  27.         <servlet-name>DispatcherServlet</servlet-name>
  28.         <url-pattern>/</url-pattern>
  29.     </servlet-mapping>
  32.     <!--防乱码-->
  33.     <filter>
  34.         <filter-name>encoding</filter-name>
  35.         <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
  36.         <init-param>
  37.             <param-name>encoding</param-name>
  38.             <param-value>utf-8</param-value>
  39.         </init-param>
  40.     </filter>
  41.     <filter-mapping>
  42.         <filter-name>encoding</filter-name>
  43.         <url-pattern>/*</url-pattern>
  44.     </filter-mapping>
  47.     <!--配置监听器，在项目启动时，同时启动Spring工厂，使得Dao和Service以及Druid连接池启动-->
  48.     <listener>
  49.         <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  50.     </listener>
  52.     <!--配置spring-mybatis文件路径-->
  53.     <!--
  54.         如果这个地方不配置的话 <init-param>
  55.         这个里面要写总的spring配置的.xml文件
  56.         这是个大坑！！！
  57.     -->
  58.     <context-param>
  59.         <param-name>contextConfigLocation</param-name>
  60.         <param-value>classpath:spring-mybatis.xml</param-value>
  61.     </context-param>
  63. </web-app>

总结：

现在才发现抄老师的代码是多么幸福的一件事！之前我都是跟着老师敲代码

现在，自己独立写代码，一步一个坑，一步一个坑！！

不过这些确实加深了我对SSM框架的理解！

加油吧少年！即使再小的帆也能远航！