从零开始···整合mybatis

接下来是整合mybatis到工程中。
首先是导入需要的jar包：

<dependency>
    <groupId>org.springframeworkgroupId>
    <artifactId>spring-jdbcartifactId>
    <version>4.3.10.RELEASEversion>
dependency> 

<dependency>
    <groupId>mysqlgroupId>
    <artifactId>mysql-connector-javaartifactId>
    <version>6.0.6version>
dependency>

<dependency>
    <groupId>com.alibabagroupId>
    <artifactId>druidartifactId>
    <version>1.1.2version>
dependency>


<dependency>
    <groupId>org.mybatisgroupId>
    <artifactId>mybatisartifactId>
    <version>3.4.1version>
dependency>
<dependency>
    <groupId>org.mybatisgroupId>
    <artifactId>mybatis-springartifactId>
    <version>1.3.0version>
dependency>

这里用到了阿里巴巴开发的druid作为数据连接池，它的基本配置可以参考
https://github.com/alibaba/druid/wiki/%E9%85%8D%E7%BD%AE_DruidDataSource%E5%8F%82%E8%80%83%E9%85%8D%E7%BD%AE
其他内容可以百度搜索。
导入所需JAR包后就要开始建立配置文件，在springMVC中整合mybatis需要以下几个配置文件
application-dao.xml

<beans xmlns="http://www.springframework.org/schema/beans" 
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   
       xmlns:mybatis="http://mybatis.org/schema/mybatis-spring"  
       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://mybatis.org/schema/mybatis-spring http://mybatis.org/schema/mybatis-spring.xsd  
       http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd">  

       
    <mybatis:scan base-package="com.rf"/>  
      
    <context:property-placeholder location="classpath:jdbc.properties"/>  

      
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" init-method="init" destroy-method="close">   
        <property name="url" value="${jdbc.url}" />  
        <property name="username" value="${jdbc.username}"/>  
        <property name="password" value="${jdbc.password}"/>  
          
        <property name="initialSize"><value>1value>property>  
        <property name="maxActive"><value>5value>property>  
        <property name="minIdle"><value>1value>property>  
          
        <property name="maxWait"><value>60000value>property>  
          
        <property name="filters"><value>statvalue>property>  
          
        <property name="timeBetweenEvictionRunsMillis"><value>60000value>property>  
          
        <property name="minEvictableIdleTimeMillis"><value>300000value>property>   
    bean>  

      
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">  
        <property name="dataSource" ref="dataSource" /> 
    bean>   
beans>

然后是.properties属性文件，如果嫌麻烦可以不要这个，一些参数直接写在上述配置文件中，比如url,username等。
下面是配置文件的目录：

接下来就是建立相关类实验一下：

这里我使用注解的方式实现动态注入，各类的注解详情如下：
controller：

@Controller
@RequestMapping("/fc")
public class FirstController {
    @Autowired
    private FirstService fService;

    @RequestMapping("/start.do")
    @ResponseBody
    public Object start(HttpServletRequest request) {
        Object result = new Object();
        result = "hello world!";
        Integer n = fService.countNum();
        result = result + "--" + n;
        return result;
    }
}

service：

@Service
public class FirstService {
    @Autowired
    private FirstDao fDao;

    public Integer countNum() {
        return fDao.countNum();
    }
}

dao：

@Repository
public class FirstDao {
    @Resource
    private FirstMapper fMapper;

    public Integer countNum() {
        return fMapper.countNum();
    }
}

最后测试一下，成功从库中查询到数据了。