一、创建Maven工程

使用的编辑器是 IntelliJ IDEA， 点击 File > New > Project，选择 Maven，勾选 Create from archetype，选择 maven-archetype-webapp。

等待 Maven 导入完成初始的包。初始的工程结构只有一个 main 里有一个 webapp 文件夹，里面有些初始内容。我们需要额外创建一些文件夹。

在 main 里分别创建 java、resources 文件夹，并分别 右键 > Mark Directory as > Source Root 和 Resource Root ，标记 java 程序的主文件夹和资源文件夹；返回上一层，在 src 里创建 test 文件夹，在 test 里创建 java 和 resources 文件夹，并分别 右键 > Mark Directory as > Test Source Root 和 Test Resource Root。在 webapp/WEB-INF/ 下创建 static 和 jsp 文件夹，分别存放静态资源和 jsp 网页模板。

完成的结构如下所示：

二、开始整合SSM

首先在 Maven 里导入相关的依赖包

pom.xml
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<dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>test</scope>
    </dependency>
    
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-context</artifactId>
        <version>5.1.3.RELEASE</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/com.alibaba/druid -->
    <dependency>
        <groupId>com.alibaba</groupId>
        <artifactId>druid</artifactId>
        <version>1.1.12</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
    <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.34</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.springframework/spring-aspects -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-aspects</artifactId>
        <version>5.1.2.RELEASE</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-jdbc</artifactId>
        <version>5.1.3.RELEASE</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.springframework/spring-orm -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-orm</artifactId>
        <version>5.1.3.RELEASE</version>
    </dependency>


    <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis -->
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis</artifactId>
        <version>3.4.6</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/com.github.pagehelper/pagehelper -->
    <dependency>
        <groupId>com.github.pagehelper</groupId>
        <artifactId>pagehelper</artifactId>
        <version>5.1.8</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/log4j/log4j -->
    <dependency>
        <groupId>log4j</groupId>
        <artifactId>log4j</artifactId>
        <version>1.2.17</version>
    </dependency>


    <!-- https://mvnrepository.com/artifact/org.mybatis/mybatis-spring -->
    <dependency>
        <groupId>org.mybatis</groupId>
        <artifactId>mybatis-spring</artifactId>
        <version>1.3.2</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.springframework/spring-web -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-web</artifactId>
        <version>5.1.3.RELEASE</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
    <dependency>
        <groupId>org.springframework</groupId>
        <artifactId>spring-webmvc</artifactId>
        <version>5.1.3.RELEASE</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/jstl/jstl -->
    <dependency>
        <groupId>jstl</groupId>
        <artifactId>jstl</artifactId>
        <version>1.2</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/taglibs/standard -->
    <dependency>
        <groupId>taglibs</groupId>
        <artifactId>standard</artifactId>
        <version>1.1.2</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/javax.servlet/servlet-api -->
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>servlet-api</artifactId>
        <version>2.5</version>
        <scope>provided</scope>
    </dependency>

    <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-core -->
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-core</artifactId>
        <version>2.9.8</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-databind -->
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.9.8</version>
    </dependency>

    <!-- https://mvnrepository.com/artifact/com.fasterxml.jackson.core/jackson-annotations -->
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-annotations</artifactId>
        <version>2.9.0</version>
    </dependency>
</dependencies>

Resource 文件夹以外的 xml 文件默认是不会被 IDEA 编译的，需要添加以下代码

pom.xml
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<build>
    <resources>
      <resource>
        <directory>src/main/java</directory>
        <includes>
          <include>**/*.xml</include>
        </includes>
      </resource>
    </resources>
</build>

保存，并等待 Maven 导包完毕。

之后我们就可以在 Resources 文件夹里创建各种配置文件，把刚才我们新建的目录都配置上。

首先是 SpringMVC 的配置

SpringMVC.xml
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<?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">


    <!-- 自动扫描该包，使SpringMVC认为包下用了 @Controller 注解的类是控制器 -->
    <context:component-scan base-package="com.crazykid.ssm.controller">
        <!--只扫描 @Controller 注解-->
        <context:include-filter type="annotation" expression="org.springframework.stereotype.Controller"/>
        <!--去掉 @Service 注解-->
        <context:exclude-filter type="annotation" expression="org.springframework.stereotype.Service"/>
    </context:component-scan>

    <!--启用注解 让其可以识别注解 @Controller-->
    <mvc:annotation-driven />

    <!--映射静态资源 比如 localhost/static/1.jpg 会读取文件 src/webapp/WEB-INF/static/1.jpg -->
    <mvc:resources mapping="/static/**" location="/WEB-INF/static/"/>

    <!-- 让SpringMVC支持请求json，响应json, json与pojo的映射 -->
    <bean class="org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter">
        <property name="messageConverters">
            <list>
                <bean class="org.springframework.http.converter.json.MappingJackson2HttpMessageConverter"></bean>
            </list>
        </property>
    </bean>

    <!-- 定义跳转的文件的前后缀 ，视图模式配置-->
    <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="prefix" value="/WEB-INF/jsp/" />
        <property name="suffix" value=".jsp" />
    </bean>
</beans>

然后是 Spring(开启注解)、MyBatis(配置数据源，引用配置文件)

spring-mybatis.xml
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<?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-4.2.xsd">


    <!--自动扫描路径下的bean并注入-->
    <context:component-scan base-package="com.crazykid.ssm"/>

    <!--配置数据源-->
    <!--引用配置文件-->
    <context:property-placeholder location="classpath:db.properties"/>
    <!--带属性的 bean，指定数据源类-->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource">
        <property name="driverClassName" value="${jdbc.driverClassName}"/>
        <property name="url" value="${jdbc.url}"/>
        <property name="username" value="${jdbc.username}"/>
        <property name="password" value="${jdbc.password}"/>
    </bean>

    <bean id="sessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <!--配置实体类 自动为 domain 起别名-->
        <property name="typeAliasesPackage" value="com.crazykid.ssm.domain"/>
        <!--载入 MyBatis 配置-->
        <property name="configLocation" value="classpath:mybatis_config.xml"/>
    </bean>

    <!-- 扫描mapper的interface -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.crazykid.ssm.dao" />
    </bean>
</beans>

数据库信息 (使用 test 数据库)

db.properties
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jdbc.driverClassName=com.mysql.jdbc.Driver
jdbc.url=jdbc:mysql://localhost:3306/test
jdbc.username=root
jdbc.password=123456

mybatis 配置文件

mybatis_config.xml
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<?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>

    <!--集成Log4j-->
    <settings>
        <setting name="logImpl" value="LOG4J"/>
    </settings>

    <!--分页插件-->
    <plugins>
        <plugin interceptor="com.github.pagehelper.PageInterceptor">
            <property name="helperDialect" value="mysql"/>
            <property name="reasonable" value="true"/>
        </plugin>
    </plugins>

    <!--扫描包路径下的mapper xml-->
    <mappers>
        <package name="com.crazykid.ssm.dao"/>
    </mappers>

</configuration>

log4j (日志模块) 的配置文件

log4j.properties
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# 全局日志配置
#log4j.rootLogger=ERROR, stdout
log4j.rootLogger=TRACE, stdout

# 控制台输出
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n

最后一步，就是配置整个程序的“访问入口”，在 webapp/WEB-INF/web.xml

web.xml
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<!DOCTYPE web-app PUBLIC
 "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
 "http://java.sun.com/dtd/web-app_2_3.dtd" >

<web-app>
  <display-name>Archetype Created Web Application</display-name>

  <!-- Spring和mybatis的配置文件 -->
  <context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:Spring-Mybatis.xml</param-value>
  </context-param>


  <!--强制转utf-8解决中文乱码-->
  <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>
    <init-param>
      <param-name>forceEncoding</param-name>
      <param-value>true</param-value>
    </init-param>
  </filter>

  <filter-mapping>
    <filter-name>characterEncodingFilter</filter-name>
    <url-pattern>/*</url-pattern>
  </filter-mapping>

  <!-- Spring监听器 -->
  <listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
  </listener>


  <!-- Spring MVC servlet -->
  <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:SpringMVC.xml</param-value>
    </init-param>
    <load-on-startup>1</load-on-startup> <!-- 启动级别-->
  </servlet>

  <servlet-mapping>
    <servlet-name>SpringMVC</servlet-name>
    <!-- 此处可以可以配置成*.do，对应struts的后缀习惯 -->
    <url-pattern>/</url-pattern>
  </servlet-mapping>

  <welcome-file-list>
    <welcome-file>/index.jsp</welcome-file>
  </welcome-file-list>

</web-app>

三、测试

在 webapp/WEB-INF/jsp 下创建 hello.jsp

hello.jsp
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<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
    <title>Title</title>
</head>
<body>
    <h1>Hello World!</h1>
</body>
</html>

在 控制层的包下创建一个 Hello 类

Hello.java
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package com.crazykid.ssm.controller;

import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;

@Controller
public class Hello {
    @RequestMapping("/hello")
    public String Hello() {
        return "hello";
    }
}

把 Tomcat 跑起来，浏览器打开 http://localhost:8080/ssmtest/hello (ssmtest为你设置的上下文路径)，显示 HelloWorld! 则代表 SpringMVC 配置成功。

接下来测试 MyBatis，在 test 数据库建立 user 表，添加一些数据。

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USE test;
CREATE TABLE IF NOT EXISTS `user`(
   `id` INT UNSIGNED AUTO_INCREMENT,
   `name` VARCHAR(100) NOT NULL,
   PRIMARY KEY ( `id` )
)ENGINE=INNODB DEFAULT CHARSET=utf8;

INSERT INTO USER (name) VALUES ('CrazyKid1');
INSERT INTO USER (name) VALUES ('CrazyKid2');
INSERT INTO USER (name) VALUES ('CrazyKid3');

现在 user 表 应该有如下内容：

id name
1 CrazyKid1
2 CrazyKid2
3 CrazyKid3

创建 pojo 类

User.java
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package com.crazykid.ssm.domain;

public class User {
    private int id;
    private String name;

    public User() {
    }
    public int getId() {
        return id;
    }
    public void setId(int id) {
        this.id = id;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", name='" + name + '\'' +
                '}';
    }
}

编写 mybatis 的一个 mapper

UserMapper.xml
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<?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.crazykid.ssm.dao.UserMapper">
    <select id="findAllUsers" resultType="com.crazykid.ssm.domain.User">
        select * from user
    </select>
</mapper>

编写它的一个实现接口

UserMapper.java
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package com.crazykid.ssm.dao;

import com.crazykid.ssm.domain.User;
import org.springframework.stereotype.Repository;

import java.util.List;

@Repository
public interface UserMapper {
    List<User> findAllUsers();
}

编写 Service 层的接口

UserService.java
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package com.crazykid.ssm.service.impl;

import com.crazykid.ssm.dao.UserMapper;
import com.crazykid.ssm.domain.User;
import com.crazykid.ssm.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class UserServiceImpl implements UserService {
    @Autowired
    private UserMapper userMapper;

    @Override
    public List<User> findAllUsers() {
        return userMapper.findAllUsers();
    }
}

编写该接口的实现类

UserServiceImpl.java
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package com.crazykid.ssm.service.impl;

import com.crazykid.ssm.dao.UserMapper;
import com.crazykid.ssm.domain.User;
import com.crazykid.ssm.service.UserService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;

@Service
public class UserServiceImpl implements UserService {
    @Autowired
    private UserMapper userMapper;

    @Override
    public List<User> findAllUsers() {
        return userMapper.findAllUsers();
    }
}

编写测试类

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import com.crazykid.ssm.domain.User;
import com.crazykid.ssm.service.impl.UserServiceImpl;
import org.junit.Test;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.util.List;

public class Tester {
    private UserServiceImpl userService;

    @Test
    public void testFindAllUsers() {
        ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext("Spring-Mybatis.xml");
        userService = (UserServiceImpl) context.getBean("userServiceImpl");
        List<User> list = userService.findAllUsers();
        System.out.println(list);
    }
}

输出结果：

看到该提示即代表 Spring + MyBatis 测试成功。

P.S 添加 Spring Test 模块后可以用注解的方式引入xml配置文件，让测试代码看上去更简洁。

pom.xml
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<!-- https://mvnrepository.com/artifact/org.springframework/spring-test -->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-test</artifactId>
    <version>5.1.4.RELEASE</version>
    <scope>test</scope>
</dependency>
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import com.crazykid.ssm.domain.User;
import com.crazykid.ssm.service.impl.UserServiceImpl;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;

import java.util.List;

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = "/Spring-Mybatis.xml")
public class Tester2 {
    @Autowired
    UserServiceImpl userService;

    @Test
    public void testFindAllUsers() {
        List<User> list = userService.findAllUsers();
        System.out.println(list);
    }
}

注意：注解测试要求 JUnit 在 4.12 版本以上，@RunWith 注解不可省略，否则会造成无法正常注入，导致空指针异常。

最后放上程序结构图：

代码下载：SSMtest.rar