SSM 项目搭建

写在前面

本文介绍最基础的 Spring+Spring MVC+MyBatis 项目框架的搭建, 演示项目->码云地址

【适合人群】：初学小白
【IDE】：Intellij IDEA 2017

开始搭建

1. 创建 web 项目

使用 idea 创建项目，直接选择从原型创建，目录结构如图

各个目录的内容这里不再赘述

要注意的是，可能 idea 自动创建「web.xml」的文件头是 2.3 的协议. 要更换文件头

<?xml version="1.0" encoding="UTF-8"?><web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"         xmlns="http://java.sun.com/xml/ns/javaee"         xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"         id="WebApp_ID" version="3.0"></web-app>

2. 添加依赖

添加 SSM 的 pom 依赖

打开「pom」文件，先在根目录添加下面的内容，对项目添加的 jar 包的版本进行统一管理

<properties>    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>    <org.mybatis.version>3.2.3</org.mybatis.version>    <org.springframework.version>4.0.0.RELEASE</org.springframework.version></properties>

然后添加需要的 jar 包， dependencies 标签下添加

        <!-- mybatis -->            <dependency>                <groupId>org.mybatis</groupId>                <artifactId>mybatis</artifactId>                <version>${org.mybatis.version}</version>            </dependency>            <!-- mybatis和spring集成包 -->            <dependency>                <groupId>org.mybatis</groupId>                <artifactId>mybatis-spring</artifactId>                <version>1.2.3</version>            </dependency>            <dependency>                <groupId>mysql</groupId>                <artifactId>mysql-connector-java</artifactId>                <version>5.1.21</version>            </dependency>            <!-- druid -->            <!-- https://mvnrepository.com/artifact/com.alibaba/druid -->            <dependency>                <groupId>com.alibaba</groupId>                <artifactId>druid</artifactId>                <version>1.0.16</version>            </dependency>            <dependency>                <groupId>junit</groupId>                <artifactId>junit</artifactId>                <version>4.12</version>                <scope>test</scope>            </dependency>            <!-- lombok -->            <dependency>                <groupId>org.projectlombok</groupId>                <artifactId>lombok</artifactId>                <version>1.16.6</version>                <scope>provided</scope>            </dependency>            <!-- common-lang -->            <dependency>                <groupId>commons-lang</groupId>                <artifactId>commons-lang</artifactId>                <version>2.6</version>            </dependency>            <!--fileupload -->            <dependency>                <groupId>commons-fileupload</groupId>                <artifactId>commons-fileupload</artifactId>                <version>1.3.1</version>            </dependency>            <!-- spring -->            <dependency>                <groupId>org.springframework</groupId>                <artifactId>spring-test</artifactId>                <version>${org.springframework.version}</version>                <scope>test</scope>            </dependency>            <dependency>                <groupId>org.springframework</groupId>                <artifactId>spring-core</artifactId>                <version>${org.springframework.version}</version>            </dependency>            <dependency>                <groupId>org.springframework</groupId>                <artifactId>spring-context</artifactId>                <version>${org.springframework.version}</version>            </dependency>            <dependency>                <groupId>org.springframework</groupId>                <artifactId>spring-context-support</artifactId>                <version>${org.springframework.version}</version>            </dependency>            <dependency>                <groupId>org.springframework</groupId>                <artifactId>spring-expression</artifactId>                <version>${org.springframework.version}</version>            </dependency>            <dependency>                <groupId>org.springframework</groupId>                <artifactId>spring-aop</artifactId>                <version>${org.springframework.version}</version>            </dependency>            <dependency>                <groupId>org.springframework</groupId>                <artifactId>spring-tx</artifactId>                <version>${org.springframework.version}</version>            </dependency>            <dependency>                <groupId>org.springframework</groupId>                <artifactId>spring-jdbc</artifactId>                <version>${org.springframework.version}</version>            </dependency>            <!-- aspectj -->            <dependency>                <groupId>org.aspectj</groupId>                <artifactId>aspectjrt</artifactId>                <version>1.7.4</version>            </dependency>            <dependency>                <groupId>org.aspectj</groupId>                <artifactId>aspectjweaver</artifactId>                <version>1.7.4</version>            </dependency>            <!-- cglib -->            <dependency>                <groupId>cglib</groupId>                <artifactId>cglib</artifactId>                <version>3.1</version>            </dependency>            <dependency>                <groupId>org.slf4j</groupId>                <artifactId>slf4j-log4j12</artifactId>                <version>1.7.12</version>            </dependency>            <!-- 引入javamail -->            <dependency>                <groupId>javax.mail</groupId>                <artifactId>mail</artifactId>                <version>1.4.4</version>            </dependency>            <!-- fastjson -->            <dependency>                <groupId>com.alibaba</groupId>                <artifactId>fastjson</artifactId>                <version>1.2.7</version>            </dependency>            <dependency>                <groupId>org.codehaus.jackson</groupId>                <artifactId>jackson-core-asl</artifactId>                <version>1.9.12</version>            </dependency>            <dependency>                <groupId>org.codehaus.jackson</groupId>                <artifactId>jackson-mapper-lgpl</artifactId>                <version>1.9.12</version>            </dependency>            <dependency>                <groupId>org.quartz-scheduler</groupId>                <artifactId>quartz</artifactId>                <version>1.8.6</version>            </dependency>            <!-- servlet-api -->            <dependency>                <groupId>javax.servlet</groupId>                <artifactId>servlet-api</artifactId>                <version>2.5</version>                <scope>provided</scope>            </dependency>            <dependency>                <groupId>org.springframework</groupId>                <artifactId>spring-web</artifactId>                <version>${org.springframework.version}</version>            </dependency>            <dependency>                <groupId>org.springframework</groupId>                <artifactId>spring-webmvc</artifactId>                <version>${org.springframework.version}</version>            </dependency>            <!--freemarker -->            <dependency>                <groupId>org.freemarker</groupId>                <artifactId>freemarker</artifactId>                <version>2.3.23</version>            </dependency>            <!-- dubbo -->            <dependency>                <groupId>com.alibaba</groupId>                <artifactId>dubbo</artifactId>                <version>2.5.3</version>                <exclusions>                    <exclusion>                        <groupId>org.springframework</groupId>                        <artifactId>spring</artifactId>                    </exclusion>                </exclusions>            </dependency>            <!-- zookeeper -->            <dependency>                <groupId>com.101tec</groupId>                <artifactId>zkclient</artifactId>                <version>0.2</version>            </dependency>            <dependency>                <groupId>org.apache.zookeeper</groupId>                <artifactId>zookeeper</artifactId>                <version>3.4.5</version>            </dependency>

上文中的依赖除了添加了 SSM 所需要的必须的依赖之外, 还有 web 开发常用的组件的依赖, 作用如下

框架 作用 Spring 强大的基于 JavaBean 的采用控制反转（IoC）原则的配置管理，使得应用程序的组件更加快捷简易。 Spring MVC 前段框架, 和 Spring 完美融合 MyBatis 持久层框架, 用于数据库连接 Druid 数据库连接池, 用于管理数据库连接 lombok 提供便捷的 getter/setter 等 fileupload 二进制文件上传支持 aspectJ 是一个面向切面的框架，它扩展了Java语言。定义了AOP语法 cglib 动态代理 javamail 提供给开发者处理电子邮件相关的编程接口 fastjson json对象的转换 freemarker 使用模板文件生成指定文件 dubbo 分布式框架 zookeeper 注册中心

2. 整合 Spring

创建配置文件「applicationContext.xml」放在「resources」文件夹下, 内容为

<?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"></beans>

因为项目使用注解的方式进行配置, 所以开启注解扫描, 先在文件头添加 xsd 引用

xmlns:context="http://www.springframework.org/schema/context"http://www.springframework.org/schema/context http://www.springframework.org/schema/context/context.xsd

效果如图

然后在 <beans> 标签下添加内容

<context:annotation-config/><context:component-scan base-package="org.nyy.ssmdemo"/>

3. 整合 MyBatis

在「resources」文件夹中创建 MyBatis 的配置文件

<?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>        <!-- 开启延迟加载 -->        <setting name="lazyLoadingEnabled" value="true"/>        <!-- 禁止访问主对象中的所有的属性都会去触发延迟加载 -->        <setting name="aggressiveLazyLoading" value="false"/>        <!-- 指定哪些Object中的方法可以触发延迟加载 -->        <setting name="lazyLoadTriggerMethods" value="clone"/>    </settings></configuration>

新建数据库并且创建「user」表, 字段如下

字段名 属性 含义 id bigint 主键 name varchar(50) 姓名 sn varchar(50) 编号

根据表, 新建实体类「User.java」

package org.nyy.ssmdemo.domain;/** * 用户实体类 */@Setter@Getter@ToStringpublic class User {    private Long id;    private String name;    private String sn;}

新建「UserMapper.java」和「UserMapper.xml」, 这两个文件是可以使用 MyBatis-generator 自动生成的, 效果是一样的, 文件内容如下

public interface UserMapper {    int deleteByPrimaryKey(Long id);    int insert(User record);    User selectByPrimaryKey(Long id);    List<User> selectAll();    int updateByPrimaryKey(User record);}

<?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="org.nyy.ssmdemo.mapper.UserMapper">    <resultMap id="BaseResultMap" type="org.nyy.ssmdemo.domain.User">        <id column="id" property="id"/>        <result column="name" property="name"/>        <result column="sn" property="sn"/>    </resultMap>    <delete id="deleteByPrimaryKey">        DELETE FROM user        WHERE id = #{id}    </delete>    <insert id="insert" useGeneratedKeys="true" keyProperty="id">        INSERT INTO user        (name, sn)        VALUES            (#{name}, #{sn})    </insert>    <update id="updateByPrimaryKey">        UPDATE user        SET            name = #{name},            sn   = #{sn}        WHERE id = #{id}    </update>    <select id="selectByPrimaryKey" resultMap="BaseResultMap" parameterType="long">        SELECT *        FROM user        WHERE id = #{id}    </select>    <select id="selectAll" resultMap="BaseResultMap">        SELECT *        FROM user    </select></mapper>

xml 的 namespace 要和接口的全限定类名一致, xml 中 sql 语句的 id 要和接口中的方法名一致

进行数据库的连接, 和事务的配置, 新建「db.properties」,同样在「resources」文件夹下

db.driver=com.mysql.jdbc.Driverdb.url=jdbc:mysql:///ssmdemodb.username=[你的数据库账户名]db.password=[你的数据库密码]

在「applicationContext.xml」中添加数据库的连接配置和事务

<!-- 引入数据库配置文件 -->    <context:property-placeholder location="classpath:db.properties"/>    <!-- 创建连接池对象 -->    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">        <property name="driverClassName" value="${db.driver}"/>        <property name="url" value="${db.url}"/>        <property name="username" value="${db.username}"/>        <property name="password" value="${db.password}"/>    </bean>    <!-- 创建sqlsession -->    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">        <property name="dataSource" ref="dataSource"/>        <property name="configLocation" value="classpath:myBatis-config.xml"/>        <property name="typeAliasesPackage" value="org.nyy.ssmdemo"/>        <property name="mapperLocations" value="classpath:org/nyy/ssmdemo/mapper/*Mapper.xml"/>    </bean>    <!-- 创建事务管理器 -->    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">        <property name="dataSource" ref="dataSource"/>    </bean>    <!-- 配置事务 -->    <tx:advice id="advice" transaction-manager="transactionManager">        <tx:attributes>            <tx:method name="list*" read-only="true"/>            <tx:method name="get*" read-only="true"/>            <tx:method name="query*" read-only="true"/>            <tx:method name="*"/>        </tx:attributes>    </tx:advice>    <!-- 配置aop -->    <aop:config>        <aop:pointcut expression="execution(* org.nyy.ssmdemo.service.*Service.*(..))" id="pointCut"/>        <aop:advisor advice-ref="advice" pointcut-ref="pointCut"/>    </aop:config>    <!-- 配置扫描mapper接口的位置 -->    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">        <property name="basePackage" value="org.nyy.ssmdemo.mapper" />    </bean>

新建测试类, 测试集成结果

/** * 测试mapper的集成 */@RunWith(SpringJUnit4ClassRunner.class)@ContextConfiguration("classpath:applicationContext.xml")public class TestMapper {    @Autowired    private UserMapper userMapper;    @Test    public void testMapper() throws Exception {        User user = new User();        user.setName("nyy");        user.setSn("NYY");        userMapper.insert(user);        System.out.println(user.getId());    }}

输出有 id, 集成成功

4 .整合 Spring MVC

配置「web.xml」处理 .do 请求和静态资源

<!-- 配置字符编码过滤器 -->    <filter>        <filter-name>characterEncoding</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>characterEncoding</filter-name>        <url-pattern>*.do</url-pattern>    </filter-mapping>    <!-- 将.do请求交给Spring MVC处理 -->    <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:applicationContext.xml</param-value>        </init-param>        <load-on-startup>1</load-on-startup>    </servlet>    <servlet-mapping>        <servlet-name>springMVC</servlet-name>        <url-pattern>*.do</url-pattern>    </servlet-mapping>

在「applicationContext.xml」中添加 mvc 的注解支持和视图解析器, 同时要引入 mvc 的约束文件, 方法和 context 约束文件的引入相同, 不在赘述

<mvc:annotation-driven/>    <!-- 配置视图解析器 -->    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">        <!-- 配置逻辑视图自动添加的后缀名 -->        <property name="suffix" value=".jsp"/>        <!-- 配置逻辑视图自动添加的前缀 -->        <property name="prefix" value="/WEB-INF/views/"/>    </bean>

新建 Controller

/** * User控制器 */@Controllerpublic class UserController {    @Autowired    private IUserService userService;    @RequestMapping("user")    public Object userList(Model model) {        model.addAttribute("user",userService.selectByPrimaryKey(1L));        return "user";    }}

其中 service 是服务层的方法, 还需要在创建「WEB-INF/views/user.jsp」文件, body 标签内容为

<body>${user}</body>

给项目配置一个 Tomcat 启动之后 访问「localhost/user.do」,效果如下

总结

本文只是介绍了怎么搭建一个最基础的项目, 搭建可能遇到的问题, 以及其他整合部分都没有介绍, 之后有机会会继续写的, 也会多探讨原理的东西