【JAVA - SSM】之SSM入门项目的搭建

        最近学习了一下SSM。SSM是 Spring + SpringMVC + MyBatis 整合框架，非常适合WEB后台开发，也是当前很多人的不二选择。这篇博客带大家来创建一个学习SSM的入门程序，从搭建框架开始，到实现一个小功能，相信新手朋友们通过这篇博客就可以基本入门开发SSM了。

        首先介绍一下本博客使用的开发环境的框架版本：

•         开发环境：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

首先打开IntelliJ IDEA开发工具，点击“Create New Project”，如下图所示：

点击后跳转到如下图所示的界面，选择“Empty Project”（如下图所示选择），然后点击“Next”按钮：

跳转到如下图所示的界面，在Project Name一栏中输入项目名称，然后点击Finish：

这时就进入项目了，但是仍然会弹出一个如下图所示的界面，在这个界面中点击图中所示的“加号”，在弹出的窗口中点击“New Module”：

由于我们是要搭建一个SSM的项目，因此我们参照下图所示的界面，一次选择“JAVA”、“Web Project”，然后点击“Next”按钮：

在弹出的界面中输入Module的名称，然后点击“Finish”按钮（IntelliJ、Android Studio这类开发工具与Eclipse不同，它们的Project相当于Eclipse中的WorkSpace，Module才相当于Eclipse中的Project，也就是说，在这类开发工具中，一个Project中可以包含多个Module）：

此时会返回上一个页面，如下图所示，可以看到，新的Module已经添加到项目中了，点击OK：

此时就正式进入到了项目中，现在项目的结构如下图所示：

由于我们的项目需要使用Maven进行版本控制，因此我们需要在项目中添加Maven。在项目名上右键选择“Add Framework Support”，如下图所示：

在弹出的页面中选择Maven，然后点击OK按钮，如下图所示：

此时会打开Maven的pom.xml文件，先在这个文件中指定项目的GroupId（一般是基本包名），然后点击右下角的“Import Changes Enable Auto-Import”。如下图所示：

等待项目加载完成，到此，我们的第一个SSM项目就搭建完成了，现在的项目文件体系架构如下图所示：

2、搭建项目框架

下图是一个基本的SSM项目的文件结构：

首先，我们需要在pom.xml中导入Maven依赖，pom.xml文件中的代码如下：

<?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绑定不成功 -->    <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文件中存储的是数据库有关的数据，如数据库驱动器、用户名、密码等。代码如下：

jdbc.driver=com.mysql.cj.jdbc.Driverjdbc.url=jdbc:mysql://localhost:3306/test?serverTimezone=UTCjdbc.username=rootjdbc.password=root

log4j.properties文件中存储的是日志相关的参数，代码如下：

# Global logging configurationlog4j.rootLogger=DEBUG, stdout# MyBatis logging configuration...log4j.logger.org.mybatis.example.BlogMapper=TRACE# Console output...log4j.appender.stdout=org.apache.log4j.ConsoleAppenderlog4j.appender.stdout.layout=org.apache.log4j.PatternLayoutlog4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

sqlmap.xml文件中存储的是MyBatis中用到的参数，这里由于和Spring进行了整合，一些代码都转到Spring的配置文件中进行维护了，这个文件中只声明类的别名。代码如下：

<?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>    <!-- 配置别名（批量扫描配置别名） -->    <typeAliases>        <package name="my.itgungnir.ssm.pojo"/>    </typeAliases></configuration>

springconf-context.xml文件中存储的是Spring中的一些几乎不发生变化的参数，如数据库连接池、SqlSessionFactory、事务管理器、mapper批量扫描、AOP等等。代码如下：

<?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">    <!-- 加载数据库配置设置 -->    <context:property-placeholder location="classpath:db.properties"/>    <!-- Druid数据库连接池配置 -->    <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批量扫描 -->    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">        <property name="basePackage" value="my.itgungnir.ssm.mappers"/>        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>    </bean>    <!-- 事务管理器 -->    <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文件中存储的是对Service接口的实现类的管理，即Service实现类的BEAN容器。代码如下：

<?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">    <!-- 操作用户信息的Service实现类 -->    <bean id="usersService" class="my.itgungnir.ssm.service.impl.UsersServiceImpl"/></beans>

springmvc.xml文件中存储的是SpringMVC中用到的一些组件，如处理器映射器、处理器适配器、试图解析器、文件上传的解析器、处理器全局扫描等。代码如下：

<?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">    <!-- 全局扫描Handler -->    <context:component-scan base-package="my.itgungnir.ssm.controller"/>    <!-- 处理器映射器和适配器 -->    <mvc:annotation-driven/>    <!-- 视图解析器 -->    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">        <property name="prefix" value="/WEB-INF/jsp/"/> <!-- 前缀 -->        <property name="suffix" value=".jsp"/> <!-- 后缀 -->    </bean>    <!-- 文件上传解析器 -->    <bean id="multipartResolver" class="org.springframework.web.multipart.commons.CommonsMultipartResolver">        <property name="maxUploadSize" value="5242880"/>    </bean></beans>

Users.java文件是数据库中的users表映射而成的实体类，代码如下：

import java.util.Date;/** * Users数据表映射成的POJO类 */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类中存储的是从数据库中读取数据的SQL语句。代码如下：

<?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">    <!-- 查询所有用户 -->    <select id="selectAllUsers" resultType="my.itgungnir.ssm.Users">        SELECT * FROM users    </select></mapper>

UsersMapper.java类是与XML文件对应的Mapper接口，其路径与XML的namespace相同。代码如下：

import pojo.Users;import java.util.List;/** * Users表的Mapper接口 */public interface UsersMapper {    // 查询所有用户    List<Users> selectAllUsers() throws Exception;}

UsersService.java类是Service接口，代码如下：

import pojo.Users;import java.util.List;/** * 映射到Users表的Service接口 */public interface UsersService {    // 查询所有用户    List<Users> selectAllUsers() throws Exception;}

UsersServiceImpl.java类是Service接口的实现类，其中持有一个UsersMapper的引用，通过mapper来处理得到数据。代码如下：

import mapper.UsersMapper;import org.springframework.beans.factory.annotation.Autowired;import pojo.Users;import service.UsersService;import java.util.List;/** * UsersService接口的实现类 */public class UsersServiceImpl implements UsersService {    @Autowired    private UsersMapper mapper;    // 查询所有用户    public List<Users> selectAllUsers() throws Exception {        return mapper.selectAllUsers();    }}

UsersController.java类是处理器类，通过service接口的动态代理来获取数据，并负责界面的跳转。代码如下：

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页面中负责从Controller中得到数据并展示。代码如下：

<%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %><%@ page contentType="text/html;charset=UTF-8" language="java" %><html><head>    <title>所有用户</title></head><body><form action="" method="post">    <table width="100%" border="1">        <tr>            <td>姓名</td>            <td>出生日期</td>            <td>性别</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、搭建服务器

我们使用的是Tomcat服务器。如果还没有给项目配置Tomcat服务器，那么是不能运行的，如下图所示，运行按钮是置灰的：

此时，我们需要按照下图所示的步骤，点击下拉三角并点击“Edit Configureations”：

跳转到下图所示的界面，按照下图所示的指示，依次点击加号、“Tomcat Server”、“Local”：

点击了“Local”之后，界面会变成如下图所示的样子，我们可以修改服务器名称、JRE版本；如果下面提示“No artifacts marked for deployment”，则点击右侧的“Fix”按钮即可解决问题。最后点击OK按钮：

完成之后，可以看到程序已经可以运行，并且已经选中了一个服务器，如下图所示：

我们可以通过点击上图中的Run或Debug运行程序，运行起来之后，在浏览器的地址栏中输入如下URL，回车运行：

http://localhost:8080/selectAllUsers.action

运行结果如下图所示：

至此，我们的第一个SSM的项目就全部完成啦！希望对大家有帮助~

最后的最后贴出这个项目的【GitHub地址】。