SSM框架搭建精简

本篇博客与其他大多数博客的不同之处在于，对依赖的添加进行了精简，避免了依赖的不必要手动添加，提高开发效率

如果你使用spring boot的话，以下纯属瞎折腾，敬请跳过。

项目结构

导入依赖

pom.xml文件

  <dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.11</version>
      <scope>test</scope>
    </dependency>

    <!-- https://mvnrepository.com/artifact/org.springframework/spring-webmvc -->
    <!--spring web mvc依赖-->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-webmvc</artifactId>
      <version>5.2.2.RELEASE</version>
    </dependency>

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

	<!--mysql依赖-->
    <!-- https://mvnrepository.com/artifact/mysql/mysql-connector-java -->
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>5.1.38</version>
    </dependency>

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

	<!--spring管理数据源依赖-->
    <!-- https://mvnrepository.com/artifact/org.springframework/spring-jdbc -->
    <dependency>
      <groupId>org.springframework</groupId>
      <artifactId>spring-jdbc</artifactId>
      <version>5.2.2.RELEASE</version>
    </dependency>

	<!--数据源依赖-->
    <!-- https://mvnrepository.com/artifact/com.mchange/c3p0 -->
    <dependency>
      <groupId>com.mchange</groupId>
      <artifactId>c3p0</artifactId>
      <version>0.9.5.2</version>
    </dependency>

  </dependencies>

值得一提的是，注入spring-webmvc依赖后，其他相关的spring依赖会自动导入，并不需要再手动添加，如spring-core,spring-bean等等
添加spring-webmvc后会自动导入这些依赖

配置文件

jdbc文件

driver=com.mysql.jdbc.Driver
url=jdbc:mysql://xxx.xxx.xxx.xxx:3306/xxx?characterEncoding=utf-8&useSSL=false
username=
password=

Web.xml文件

<!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>

    <listener>
      <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
    </listener>

	<!--配置spring context配置文件位置-->
    <context-param>
      <param-name>contextConfigLocation</param-name>
      <param-value>classpath:applicatioinContext.xml</param-value>
    </context-param>

	<!--配置DispatcherServlet-->
    <servlet>
      <servlet-name>app</servlet-name>
      <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
      <init-param>
        <param-name>contextConfigLocation</param-name>
        <param-value></param-value>
      </init-param>
      <load-on-startup>1</load-on-startup>
    </servlet>

    <servlet-mapping>
      <servlet-name>app</servlet-name>
      <url-pattern>/</url-pattern>
    </servlet-mapping>

</web-app>

applicationContext文件
需要注意的是，spring-servlet跟spring-mybatis只是spring上下文配置的子配置文件而已，因此在web.xml中只需指定applicationContext为spring的上下文配置文件即可

<?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
        https://www.springframework.org/schema/beans/spring-beans.xsd">
	<!--导入spring配置文件-->
    <import resource="classpath:spring/*.xml" />

</beans>

spring-servlet文件

<?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
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd http://www.springframework.org/schema/mvc https://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <!--Enable MVC Configuration-->
    <mvc:annotation-driven/>

    <!--Scan web component-->
    <!--即扫描controller以及service注解等-->
    <context:component-scan base-package="xyz.rosewuu"/>

	<!--处理静态文件的请求-->
    <mvc:default-servlet-handler/>

    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver">
        <property name="viewClass" value="org.springframework.web.servlet.view.JstlView"/>
        <property name="prefix" value="/WEB-INF/jsp/"/>
        <property name="suffix" value=".jsp"/>
    </bean>
</beans>

spring-mybatis文件

<?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
        https://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/context
        https://www.springframework.org/schema/context/spring-context.xsd">

    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="mapperLocations" value="classpath:mapper/*.xml" />
    </bean>
	<!--引入jdbc配置文件-->
    <context:property-placeholder location="classpath:config/jdbc.properties" />
    <bean id="dataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource">
        <property name="driverClass" value="${driver}" />
        <property name="jdbcUrl" value="${url}" />
        <property name="user" value="${username}" />
        <property name="password" value="${password}" />
    </bean>

	<!--配置SqlSessionTemplate，获取sqlSession-->
    <bean id="sqlSession" class="org.mybatis.spring.SqlSessionTemplate">
        <constructor-arg index="0" ref="sqlSessionFactory" />
    </bean>

	<!--注入SqlSessionTemplate-->
    <bean id="testService" class="xyz.rosewuu.service.impl.TestServiceImpl">
        <property name="sqlSession" ref="sqlSession" />
    </bean>
</beans>

数据库结构

测试类

控制类

package xyz.rosewuu.controller;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.ResponseBody;
import xyz.rosewuu.service.TestService;

import java.io.IOException;

@Controller
public class Test {
    @Autowired
    private TestService testService;

    @RequestMapping("/test")
    @ResponseBody
    public String hello() throws IOException {
        testService.hello();
        return "Hello";
    }

}

实体类

package xyz.rosewuu.entity;

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

    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 "Test{" +
                "id=" + id +
                ", name='" + name + '\'' +
                '}';
    }
}

但本人并不建议实体类自己手动添加getter/setter等方法，因为一旦修改变量则工作变得繁琐。因此我推荐在IDEA中安装Lombok插件，具体可参考这里https://www.zhihu.com/question/42348457
Service层接口

package xyz.rosewuu.service;

import java.io.IOException;

public interface TestService {
    void test() throws IOException;
}

Service层实现类

package xyz.rosewuu.service.impl;

import org.apache.ibatis.session.SqlSession;
import org.springframework.stereotype.Service;
import xyz.rosewuu.entity.Test;
import xyz.rosewuu.mapper.TestMapper;
import xyz.rosewuu.service.TestService;

import java.io.IOException;

@Service
public class TestServiceImpl implements TestService {
    private SqlSession sqlSession;

    public void setSqlSession(SqlSession sqlSession){
        this.sqlSession = sqlSession;
    }
    @Override
    public void test() throws IOException {
        Test test = sqlSession.getMapper(TestMapper.class).test();
        System.out.println(test);
    }
}

Dao接口（Mapper）

package xyz.rosewuu.mapper;

import xyz.rosewuu.entity.Test;

public interface TestMapper {
    Test test();
}

Mapper配置文件

<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">

<mapper namespace="xyz.rosewuu.mapper.TestMapper">
    <select id="test" resultType="xyz.rosewuu.entity.Test">
        select * from test
    </select>
</mapper>

从mapper到mapper配置文件语句生成的这个过程，其实也是可以减少自己的工作量，那就是使用MybatisX插件，具体安装过程自己可快速搜索一下。

最终效果