最近學習了一下SSM。SSM是 Spring + SpringMVC + MyBatis 整合框架，非常適合WEB后台開發，也是當前很多人的不二選擇。這篇博客帶大家來創建一個學習SSM的入門程序，從搭建框架開始，到實現一個小功能，相信新手朋友們通過這篇博客就可以基本入門開發SSM了。
首先介紹一下本博客使用的開發環境的框架版本：
- 開發環境：IntelliJ IDEA 2016.3 + Tomcat 8.5.8 + Maven
- Spring（MVC）版本：4.3.4.RELEASE
- MyBatis版本：2.8.5
1、新建工程
首先打開IntelliJ IDEA開發工具，點擊“Create New Project”，如下圖所示：
點擊后跳轉到如下圖所示的界面，選擇“Empty Project”（如下圖所示選擇），然后點擊“Next”按鈕：
跳轉到如下圖所示的界面，在Project Name一欄中輸入項目名稱，然后點擊Finish：
這時就進入項目了，但是仍然會彈出一個如下圖所示的界面，在這個界面中點擊圖中所示的“加號”，在彈出的窗口中點擊“New Module”：
由於我們是要搭建一個SSM的項目，因此我們參照下圖所示的界面，一次選擇“JAVA”、“Web Project”，然后點擊“Next”按鈕：
在彈出的界面中輸入Module的名稱，然后點擊“Finish”按鈕（IntelliJ、Android Studio這類開發工具與Eclipse不同，它們的Project相當於Eclipse中的WorkSpace，Module才相當於Eclipse中的Project，也就是說，在這類開發工具中，一個Project中可以包含多個Module）：
此時會返回上一個頁面，如下圖所示，可以看到，新的Module已經添加到項目中了，點擊OK：
此時就正式進入到了項目中，現在項目的結構如下圖所示：
由於我們的項目需要使用Maven進行版本控制，因此我們需要在項目中添加Maven。在項目名上右鍵選擇“Add Framework Support”，如下圖所示：
在彈出的頁面中選擇Maven，然后點擊OK按鈕，如下圖所示：
此時會打開Maven的pom.xml文件，先在這個文件中指定項目的GroupId（一般是基本包名），然后點擊右下角的“Import Changes Enable Auto-Import”。如下圖所示：
等待項目加載完成，到此，我們的第一個SSM項目就搭建完成了，現在的項目文件體系架構如下圖所示：
2、搭建項目框架
下圖是一個基本的SSM項目的文件結構：
首先，我們需要在pom.xml中導入Maven依賴，pom.xml文件中的代碼如下：
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>my.itgungnir.ssm</groupId> <artifactId>SSMTemplate</artifactId> <version>1.0-SNAPSHOT</version> <!-- 避免Mapper.xml和Mapper.java綁定不成功 --> <build> <resources> <resource> <directory>src/main/resources</directory> <includes> <include>**/*.properties</include> <include>**/*.xml</include> <include>**/*.tld</include> <include>**/*.jsp</include> </includes> <filtering>true</filtering> </resource> <resource> <directory>src/main/java</directory> <includes> <include>**/*.properties</include> <include>**/*.xml</include> <include>**/*.tld</include> </includes> <filtering>true</filtering> </resource> </resources> </build> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <spring.version>4.3.4.RELEASE</spring.version> <jackson.version>2.8.5</jackson.version> </properties> <dependencies> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>3.8.1</version> <scope>test</scope> </dependency> <dependency> <groupId>aopalliance</groupId> <artifactId>aopalliance</artifactId> <version>1.0</version> </dependency> <dependency> <groupId>asm</groupId> <artifactId>asm</artifactId> <version>3.3.1</version> </dependency> <dependency> <groupId>org.aspectj</groupId> <artifactId>aspectjweaver</artifactId> <version>1.8.9</version> </dependency> <dependency> <groupId>org.bouncycastle</groupId> <artifactId>bcprov-ext-jdk15on</artifactId> <version>1.55</version> </dependency> <dependency> <groupId>com.alibaba</groupId> <artifactId>druid</artifactId> <version>1.0.18</version> </dependency> <dependency> <groupId>cglib</groupId> <artifactId>cglib</artifactId> <version>3.2.4</version> </dependency> <dependency> <groupId>cglib</groupId> <artifactId>cglib-nodep</artifactId> <version>3.2.4</version> </dependency> <dependency> <groupId>com.fasterxml</groupId> <artifactId>classmate</artifactId> <version>1.3.1</version> </dependency> <dependency> <groupId>commons-codec</groupId> <artifactId>commons-codec</artifactId> <version>1.10</version> </dependency> <dependency> <groupId>commons-dbcp</groupId> <artifactId>commons-dbcp</artifactId> <version>1.4</version> </dependency> <dependency> <groupId>commons-fileupload</groupId> <artifactId>commons-fileupload</artifactId> <version>1.3.1</version> </dependency> <dependency> <groupId>commons-io</groupId> <artifactId>commons-io</artifactId> <version>2.4</version> </dependency> <dependency> <groupId>commons-logging</groupId> <artifactId>commons-logging</artifactId> <version>1.2</version> </dependency> <dependency> <groupId>commons-pool</groupId> <artifactId>commons-pool</artifactId> <version>1.6</version> </dependency> <dependency> <groupId>org.hibernate</groupId> <artifactId>hibernate-validator</artifactId> <version>5.2.4.Final</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-annotations</artifactId> <version>${jackson.version}</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-core</artifactId> <version>${jackson.version}</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>${jackson.version}</version> </dependency> <dependency> <groupId>org.javassist</groupId> <artifactId>javassist</artifactId> <version>3.21.0-GA</version> </dependency> <dependency> <groupId>javax</groupId> <artifactId>javaee-api</artifactId> <version>7.0</version> </dependency> <dependency> <groupId>org.jboss.logging</groupId> <artifactId>jboss-logging</artifactId> <version>3.3.0.Final</version> </dependency> <dependency> <groupId>javax.servlet</groupId> <artifactId>jstl</artifactId> <version>1.2</version> </dependency> <dependency> <groupId>log4j</groupId> <artifactId>log4j</artifactId> <version>1.2.17</version> </dependency> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-api</artifactId> <version>2.7</version> </dependency> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-core</artifactId> <version>2.7</version> </dependency> <dependency> <groupId>javax.mail</groupId> <artifactId>mail</artifactId> <version>1.4.7</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis</artifactId> <version>3.4.0</version> </dependency> <dependency> <groupId>org.mybatis</groupId> <artifactId>mybatis-spring</artifactId> <version>1.3.0</version> </dependency> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <version>6.0.5</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-api</artifactId> <version>1.7.21</version> </dependency> <dependency> <groupId>org.slf4j</groupId> <artifactId>slf4j-log4j12</artifactId> <version>1.7.21</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aop</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-aspects</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-beans</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-context-support</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-core</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-expression</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-jdbc</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-orm</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-oxm</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-tx</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-web</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>${spring.version}</version> </dependency> <dependency> <groupId>javax.validation</groupId> <artifactId>validation-api</artifactId> <version>1.1.0.Final</version> </dependency> </dependencies> </project>
db.properties文件中存儲的是數據庫有關的數據，如數據庫驅動器、用戶名、密碼等。代碼如下：
jdbc.driver=com.mysql.cj.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/test?serverTimezone=UTC
jdbc.username=root
jdbc.password=root
log4j.properties文件中存儲的是日志相關的參數，代碼如下：
# Global logging configuration
log4j.rootLogger=DEBUG, stdout
# MyBatis logging configuration...
log4j.logger.org.mybatis.example.BlogMapper=TRACE
# Console output...
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n
sqlmap.xml文件中存儲的是MyBatis中用到的參數，這里由於和Spring進行了整合，一些代碼都轉到Spring的配置文件中進行維護了，這個文件中只聲明類的別名。代碼如下：
<?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> <!-- 配置別名（批量掃描配置別名） --> <typeAliases> <package name="my.itgungnir.ssm.pojo"/> </typeAliases> </configuration>
springconf-context.xml文件中存儲的是Spring中的一些幾乎不發生變化的參數，如數據庫連接池、SqlSessionFactory、事務管理器、mapper批量掃描、AOP等等。代碼如下：
<?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 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/aop http://www.springframework.org/schema/aop/spring-aop.xsd"> <!-- 加載數據庫配置設置 --> <context:property-placeholder location="classpath:db.properties"/> <!-- Druid數據庫連接池配置 --> <bean name="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close"> <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="1"/> <property name="maxActive" value="20"/> <property name="minIdle" value="0"/> <property name="maxWait" value="60000"/> <property name="poolPreparedStatements" value="true"/> <property name="maxPoolPreparedStatementPerConnectionSize" value="33"/> <property name="validationQuery" value="SELECT 'x' FROM DUAL"/> <property name="testOnBorrow" value="false"/> <property name="testOnReturn" value="false"/> <property name="testWhileIdle" value="true"/> <property name="timeBetweenEvictionRunsMillis" value="60000"/> <property name="minEvictableIdleTimeMillis" value="25200000"/> <property name="removeAbandoned" value="true"/> <property name="removeAbandonedTimeout" value="1800"/> <property name="logAbandoned" value="true"/> <property name="filters" value="mergeStat"/> </bean> <!-- 配置SqlSessionFactory --> <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean"> <property name="dataSource" ref="dataSource"/> <property name="configLocation" value="classpath:mybatis/sqlmap.xml"/> </bean> <!-- mapper批量掃描 --> <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer"> <property name="basePackage" value="my.itgungnir.ssm.mappers"/> <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/> </bean> <!-- 事務管理器 --> <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"> <property name="dataSource" ref="dataSource"/> </bean> <!-- 通知 --> <tx:advice id="txAdvice" transaction-manager="transactionManager"> <tx:attributes> <tx:method name="save*" propagation="REQUIRED"/> <tx:method name="delete*" propagation="REQUIRED"/> <tx:method name="insert*" propagation="REQUIRED"/> <tx:method name="update*" propagation="REQUIRED"/> <tx:method name="find*" propagation="SUPPORTS" read-only="true"/> <tx:method name="get*" propagation="SUPPORTS" read-only="true"/> <tx:method name="select*" propagation="SUPPORTS" read-only="true"/> </tx:attributes> </tx:advice> <!-- AOP --> <aop:config> <aop:advisor advice-ref="txAdvice" pointcut="execution(* my.itgungnir.ssm.service.impl.*.*(..))"/> </aop:config> </beans>
springconf-service.xml文件中存儲的是對Service接口的實現類的管理，即Service實現類的BEAN容器。代碼如下：
<?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"> <!-- 操作用戶信息的Service實現類 --> <bean id="usersService" class="my.itgungnir.ssm.service.impl.UsersServiceImpl"/> </beans>
springmvc.xml文件中存儲的是SpringMVC中用到的一些組件，如處理器映射器、處理器適配器、試圖解析器、文件上傳的解析器、處理器全局掃描等。代碼如下：
<?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"> <!-- 全局掃描Handler --> <context:component-scan base-package="my.itgungnir.ssm.controller"/> <!-- 處理器映射器和適配器 --> <mvc:annotation-driven/> <!-- 視圖解析器 --> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <property name="prefix" value="/WEB-INF/jsp/"/> <!-- 前綴 --> <property name="suffix" value=".jsp"/> <!-- 后綴 --> </bean> <!-- 文件上傳解析器 --> <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver"> <property name="maxUploadSize" value="5242880"/> </bean> </beans>
web.xml中的代碼如下：
<?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_3_1.xsd" version="3.1"> <display-name>ONE</display-name> <!-- 加載spring容器 --> <context-param> <param-name>contextConfigLocation</param-name> <!-- /WEB-INF/classes/spring/applicationContext-*.xml這里的路徑設置是怎么回事--> <param-value>/WEB-INF/classes/spring/springconf-context.xml</param-value> </context-param> <listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class> </listener> <!-- springmvc前端控制器 --> <servlet> <servlet-name>springmvc</servlet-name> <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class> <!-- contextConfigLocation配置springmvc加載的配置文件（配置處理器映射器、適配器等等） --> <init-param> <param-name>contextConfigLocation</param-name> <param-value>classpath:spring/springmvc.xml</param-value> </init-param> <!-- <load-on-startup>1</load-on-startup> --> </servlet> <servlet-mapping> <servlet-name>springmvc</servlet-name> <url-pattern>*.action</url-pattern> </servlet-mapping> <!--配置Druid數據庫連接池的內置監控 --> <servlet> <servlet-name>DruidStatView</servlet-name> <servlet-class>com.alibaba.druid.support.http.StatViewServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>DruidStatView</servlet-name> <url-pattern>/druid/*</url-pattern> </servlet-mapping> <!-- post亂碼過慮器 --> <filter> <filter-name>CharacterEncodingFilter</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>CharacterEncodingFilter</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <!--設置session存活時間 --> <session-config> <session-timeout>60</session-timeout> </session-config> <welcome-file-list> <welcome-file>index.html</welcome-file> <welcome-file>index.htm</welcome-file> <welcome-file>index.jsp</welcome-file> <welcome-file>default.html</welcome-file> <welcome-file>default.htm</welcome-file> <welcome-file>default.jsp</welcome-file> </welcome-file-list> </web-app>
Users.java文件是數據庫中的users表映射而成的實體類，代碼如下：
import java.util.Date; /** * Users數據表映射成的POJO類 */ public class Users { private Integer id; private String username; private Date birthday; private Character sex; private String address; public Users() { } public Users(String username, Date birthday, Character sex, String address) { this.username = username; this.birthday = birthday; this.sex = sex; this.address = address; } public Users(Integer id, String username, Date birthday, Character sex, String address) { this.id = id; this.username = username; this.birthday = birthday; this.sex = sex; this.address = address; } public Integer getId() { return id; } public void setId(Integer id) { this.id = id; } public String getUsername() { return username; } public void setUsername(String username) { this.username = username; } public Date getBirthday() { return birthday; } public void setBirthday(Date birthday) { this.birthday = birthday; } public Character getSex() { return sex; } public void setSex(Character sex) { this.sex = sex; } public String getAddress() { return address; } public void setAddress(String address) { this.address = address; } }
UsersMapper.xml類中存儲的是從數據庫中讀取數據的SQL語句。代碼如下：
<?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="my.itgungnir.ssm.mappers.UsersMapper">
<!-- 查詢所有用戶 -->
<select id="selectAllUsers" resultType="my.itgungnir.ssm.Users">
SELECT * FROM users
</select>
</mapper>
UsersMapper.java類是與XML文件對應的Mapper接口，其路徑與XML的namespace相同。代碼如下：
import pojo.Users; import java.util.List; /** * Users表的Mapper接口 */ public interface UsersMapper { // 查詢所有用戶 List<Users> selectAllUsers() throws Exception; }
UsersService.java類是Service接口，代碼如下：
import pojo.Users; import java.util.List; /** * 映射到Users表的Service接口 */ public interface UsersService { // 查詢所有用戶 List<Users> selectAllUsers() throws Exception; }
UsersServiceImpl.java類是Service接口的實現類，其中持有一個UsersMapper的引用，通過mapper來處理得到數據。代碼如下：
import mapper.UsersMapper; import org.springframework.beans.factory.annotation.Autowired; import pojo.Users; import service.UsersService; import java.util.List; /** * UsersService接口的實現類 */ public class UsersServiceImpl implements UsersService { @Autowired private UsersMapper mapper; // 查詢所有用戶 public List<Users> selectAllUsers() throws Exception { return mapper.selectAllUsers(); } }
UsersController.java類是處理器類，通過service接口的動態代理來獲取數據，並負責界面的跳轉。代碼如下：
import org.springframework.beans.factory.annotation.Autowired; import org.springframework.ui.Model; import org.springframework.web.bind.annotation.RequestMapping; import pojo.Users; import service.UsersService; import java.util.List; /** * Users的Controller */ @Controller public class UsersController { @Autowired private UsersService service; @RequestMapping("selectAllUsers.action") public String selectAllUsers(Model model) throws Exception { List<Users> users = service.selectAllUsers(); model.addAttribute("users", users); return "users/allusers"; } }
allusers.jsp頁面中負責從Controller中得到數據並展示。代碼如下：
<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %> <%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>所有用戶</title> </head> <body> <form action="" method="post"> <table width="100%" border="1"> <tr> <td>姓名</td> <td>出生日期</td> <td>性別</td> <td>地址</td> </tr> <c:forEach items="${users}" var="user"> <tr> <td>${user.username}</td> <td>${user.birthday}</td> <td>${user.sex}</td> <td>${user.address}</td> </tr> </c:forEach> </table> </form> </body> </html>
3、搭建服務器
我們使用的是Tomcat服務器。如果還沒有給項目配置Tomcat服務器，那么是不能運行的，如下圖所示，運行按鈕是置灰的：
此時，我們需要按照下圖所示的步驟，點擊下拉三角並點擊“Edit Configureations”：
跳轉到下圖所示的界面，按照下圖所示的指示，依次點擊加號、“Tomcat Server”、“Local”：
點擊了“Local”之后，界面會變成如下圖所示的樣子，我們可以修改服務器名稱、JRE版本；如果下面提示“No artifacts marked for deployment”，則點擊右側的“Fix”按鈕即可解決問題。最后點擊OK按鈕：
完成之后，可以看到程序已經可以運行，並且已經選中了一個服務器，如下圖所示：
我們可以通過點擊上圖中的Run或Debug運行程序，運行起來之后，在瀏覽器的地址欄中輸入如下URL，回車運行：
http://localhost:8080/selectAllUsers.action
運行結果如下圖所示：
至此，我們的第一個SSM的項目就全部完成啦！希望對大家有幫助~
最后的最后貼出這個項目的【GitHub地址】。