mybatis學習筆記03--與spring集成

1.傳統dao開發模式的集成

這裏所謂的傳統dao開發模式指的是不使用mybatis的mapper接口。首先建立新的maven工程（如果您對maven不熟悉，請查看其它相關資料），添加spring、mybatis的依賴。maven依賴的代碼如下：

<dependencies>
        <!-- spring -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-jdbc</artifactId>
            <version>3.2.5.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-context</artifactId>
            <version>3.2.5.RELEASE</version>
        </dependency>

        <!-- mybatis -->
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis-spring</artifactId>
            <version>1.2.2</version>
        </dependency>
        <dependency>
            <groupId>org.mybatis</groupId>
            <artifactId>mybatis</artifactId>
            <version>3.3.1</version>
        </dependency>

        <dependency>
            <groupId>commons-dbcp</groupId>
            <artifactId>commons-dbcp</artifactId>
            <version>1.4</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.0.8</version>
        </dependency>

        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.10</version>
            <scope>test</scope>
        </dependency>

jar包的依賴配好了，下來寫spring的配置文件，spring.xml：

 <context:property-placeholder location="classpath:jdbc.properties"/>

 <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" 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}" />
        <property name="initialSize" value="${db.initialSize}" />
        <property name="maxActive" value="${db.maxActive}" />
        <property name="validationQuery" value="${db.validationQuery}" />
     </bean>

    <!-- 創建SqlSessionFactory，同時指定數據源 -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <!--mybatis配置文件的路徑-->
        <property name="configLocation" value="mybatis-conf.xml"/>
    </bean>

    <bean id="userDao" class="com.jackie.springmybatis.dao.impl.UserDaoImpl">
        <property name="sqlSessionFactory" ref="sqlSessionFactory"/>
    </bean>

spring的配置文件寫完了，其中的jdbc.properties文件配置了連接數據庫的基本信息，代碼如下：

db.driver=com.mysql.jdbc.Driver
db.url=jdbc\:mysql\://192.168.1.104\:3306/test?characterEncoding\=UTF-8
db.username=root
db.password=123456
db.minIdle=5
db.maxIdle=10
db.maxWait=5
db.maxActive=20
db.initialSize=10
db.validationQuery=SELECT 1

現在看一下項目的結構：

mybatis的配置文件代碼如下：

<configuration>
    <!-- 別名定義 -->
    <typeAliases>
        <package name="com.jackie.springmybatis.domain"/>
    </typeAliases>

    <!-- 加載 映射文件, 這裏注意mapper文件的路徑 -->
    <mappers>
        <mapper resource="mapper/User.xml"/>
    </mappers>

</configuration>

再來看一下java的相關代碼：

public interface UserDao {
    void insert(User user);
    User selectByPrimaryKey(Integer id);
}

//實現類要繼承SqlSessionDaoSupport 類，並且在spring的配置文件中，已經注入了sqlSessionFactory對象
public class UserDaoImpl extends SqlSessionDaoSupport implements UserDao {

    public void insert(User user) {
        SqlSession session = this.getSqlSession();
        session.insert("test.insertUser", user);
    }

    public User selectByPrimaryKey(Integer id) {
        SqlSession session = this.getSqlSession();
        User user = session.selectOne("test.selectByPrimaryKey", id);
        return user;
    }

}

java代碼寫完後，還差一個mapper.xml文件，在這裏我們寫成User.xml，代碼如下：

<mapper namespace="test">
    <insert id="insertUser" parameterType="User">
         insert into nsl_yh (id, name, user_login_id, cellphone, password1 )
         values (#{id}, #{name}, #{userLoginId},    #{cellphone}, #{password1} )
    </insert>

    <select id="selectByPrimaryKey" resultType="User" parameterType="java.lang.Integer" >
        select  
            id,
            name,
            user_login_id userLoginId,
            cellphone,
            password1
        from nsl_yh
        where id = #{id}
  </select>

OK，集成完了，看一下測試代碼：

public class UserDaoTest {
    private ApplicationContext factory;
    @Before
    public void setUp() throws Exception {
        factory = new ClassPathXmlApplicationContext("spring.xml");
    }

    @Test
    public void testInsert() {
        UserDao userDao = (UserDao)factory.getBean("userDao");
        User user = new User();
        user.setName("王ss");
        user.setCellphone("111111111");
        user.setUserLoginId("wss");
        userDao.insert(user);
    }

}

完整代碼請看：https://github.com/maodou95838/springmybatis

2.spring與mpper接口開發方式集成

還是使用上面搭建好的環境，maven的依賴配置不用改變。先來看spring配置文件的變化：

<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:mybatis="http://mybatis.org/schema/mybatis-spring"
    xsi:schemaLocation="http://www.springframework.org/schema/beans 
        http://www.springframework.org/schema/beans/spring-beans-3.2.xsd 
        http://www.springframework.org/schema/context 
        http://www.springframework.org/schema/context/spring-context-3.2.xsd 
        http://www.springframework.org/schema/tx 
        http://www.springframework.org/schema/tx/spring-tx-3.2.xsd 
        http://mybatis.org/schema/mybatis-spring
        http://mybatis.org/schema/mybatis-spring.xsd">

    <!-- 配置數據源 -->
    <context:property-placeholder location="classpath:jdbc.properties"/>

    <bean id="dataSource" class="org.apache.commons.dbcp.BasicDataSource" 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}" />
        <property name="initialSize" value="${db.initialSize}" />
        <property name="maxActive" value="${db.maxActive}" />
        <property name="validationQuery" value="${db.validationQuery}" />
     </bean>

    <!-- 創建SqlSessionFactory，同時指定數據源 -->
    <!--對實體類進行批量重命名-->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="typeAliasesPackage" value="com.jackie.springmybatis.domain"/>
    </bean>

    <!--指定mapper接口的包名-->
    <!--需要引入mybatis的命名空間，請看文件頭-->
    <mybatis:scan base-package="com.jackie.springmybatis.dao" factory-ref="sqlSessionFactory"/>

 </beans>

要注意的問題：mapper接口和mapper.xml在一個包下，並且接口名稱和文件名稱一樣。工程結構如下：

由圖可以看出，已經沒有dao的實現類。並且，也沒有了mybatis-conf.properties文件。下面請看dao層的java代碼：

package com.jackie.springmybatis.dao;

import com.jackie.springmybatis.domain.User;

/**
 * 用戶dao接口
 * 
 * @author Jackie
 *
 */
public interface UserDao {
    void insertUser(User user);

    User selectByPrimaryKey(Integer id);
}

UserDao.xml的代碼如下：

<mapper namespace="com.jackie.springmybatis.dao.UserDao">
    <insert id="insertUser" parameterType="User">
         insert into nsl_yh (id, name, user_login_id, cellphone, password1 )
         values (#{id}, #{name}, #{userLoginId},    #{cellphone}, #{password1} )
    </insert>

    <select id="selectByPrimaryKey" resultType="User" parameterType="java.lang.Integer" >
        select  
            id,
            name,
            user_login_id userLoginId,
            cellphone,
            password1
        from nsl_yh
        where id = #{id}
  </select>

</mapper>

到此，mapper接口的方式集成完畢！下面看測試代碼：

public class UserDaoTest {
    private ApplicationContext factory;
    @Before
    public void setUp() throws Exception {
        factory = new ClassPathXmlApplicationContext("spring.xml");
    }

    @Test
    public void testInsert() {
        UserDao userDao = (UserDao)factory.getBean("userDao");
        User user = new User();
        user.setName("王ss");
        user.setCellphone("111111111");
        user.setUserLoginId("wss");
        userDao.insertUser(user);
    }

}

這種方式與spring集成後，不用再spring的配置文件配置dao層，也沒法配，在項目啓動時，會自動將dao層的bean添加到spring的容器。命名方式是類名的第一個字母小寫，其他不變。請看測試用例中獲取userDao的代碼。
代碼請看：https://github.com/maodou95838/springmybatismapper
OK，Enjoy！