Spring 整合 MyBatis (Maven + MySQL) 圖文教程：從項目創建到數據訪問完整流程

前言

Spring + MyBatis 是 Java 傳統企業級開發的黃金組合。本文基於 Maven 多模塊規範，從零構建 Web 項目，完成 Spring 4.x + MyBatis 3.x + MySQL 整合，實現數據庫 CRUD 訪問。

第一階段：Maven Web 項目創建 (Eclipse)

1. File → New → Other → Maven Project
2. 勾選 Create a simple project (不使用原型)
3. Group Id: com.zhangguo, Artifact Id: Spring061, Packaging: war
4. 修正 Java 版本：項目屬性 → Project Facets → Java 1.7
5. 轉為 Web 項目：取消勾選 Dynamic Web Module → 重新勾選 3.0 → Further Configuration → Generate web.xml
6. 調整目錄：將 WebContent/META-INF, WEB-INF 移至 src/main/webapp，刪除 WebContent
7. 修正 Deployment Assembly：移除 src/test/java, src/test/resources, WebContent；添加 src/main/webapp 為部署根目錄
8. 創建 index.jsp 測試，配置 Tomcat 7 運行驗證

第二階段：MyBatis 獨立訪問 MySQL (為整合鋪路)

1. 依賴 (pom.xml)

<dependencies>
    <dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><version>5.1.38</version></dependency>
    <dependency><groupId>org.apache.logging.log4j</groupId><artifactId>log4j-core</artifactId><version>2.6.1</version></dependency>
    <dependency><groupId>org.mybatis</groupId><artifactId>mybatis</artifactId><version>3.4.1</version></dependency>
    <dependency><groupId>junit</groupId><artifactId>junit</artifactId><version>4.10</version></dependency>
</dependencies>

2. 數據庫準備

CREATE TABLE booktypes (
    id INT PRIMARY KEY AUTO_INCREMENT,
    typeName VARCHAR(100) NOT NULL
);
INSERT INTO booktypes VALUES (1, '計算機軟件開發'), (2, '計算機網絡工程');

3. 實體類

package com.zhangguo.Spring61.entities;
public class BookType {
    private int id;
    private String typeName;
    // getter/setter
}

4. Mapper 接口 + XML

// BookTypeDAO.java
public interface BookTypeDAO {
    List<BookType> getAllBookTypes();
}

// BookTypeMapper.xml
<mapper namespace="com.zhangguo.Spring61.mapping.BookTypeDAO">
    <select id="getAllBookTypes" resultType="BookType">
        SELECT id, typeName FROM booktypes
    </select>
</mapper>

5. MyBatis 核心配置

<configuration>
    <properties resource="db.properties"/>
    <typeAliases><package name="com.zhangguo.Spring61.entities"/></typeAliases>
    <environments default="development">
        <environment id="development">
            <transactionManager type="JDBC"/>
            <dataSource type="POOLED">
                <property name="driver" value="${driver}"/>
                <property name="url" value="${url}"/>
                <property name="username" value="${username}"/>
                <property name="password" value="${password}"/>
            </dataSource>
        </environment>
    </environments>
    <mappers>
        <mapper resource="com/zhangguo/Spring61/mapping/BookTypeMapper.xml"/>
    </mappers>
</configuration>


driver=com.mysql.jdbc.Driver
url=jdbc:mysql://localhost:3306/db2
username=root
password=root

6. 工具類與實現

// MyBatisUtil.java - 單例 SqlSessionFactory
public abstract class MyBatisUtil {
    private static SqlSessionFactory factory;
    public static SqlSessionFactory getSqlSessionFactory() {
        if (factory == null) {
            InputStream is = MyBatisUtil.class.getClassLoader().getResourceAsStream("MyBatisCfg.xml");
            factory = new SqlSessionFactoryBuilder().build(is);
        }
        return factory;
    }
    public static SqlSession getSession() { return getSqlSessionFactory().openSession(true); }
}

// BookTypeDAOImpl.java
public class BookTypeDAOImpl implements BookTypeDAO {
    public List<BookType> getAllBookTypes() {
        try (SqlSession session = MyBatisUtil.getSession()) {
            return session.getMapper(BookTypeDAO.class).getAllBookTypes();
        }
    }
}

第三階段：Spring 整合 MyBatis (核心重點)

1. 額外依賴

<dependency><groupId>org.mybatis</groupId><artifactId>mybatis-spring</artifactId><version>1.3.1</version></dependency>
<dependency><groupId>org.springframework</groupId><artifactId>spring-jdbc</artifactId><version>4.3.10.RELEASE</version></dependency>
<dependency><groupId>org.springframework</groupId><artifactId>spring-tx</artifactId><version>4.3.10.RELEASE</version></dependency>
<dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.1.10</version></dependency> <!-- 推薦連接池 -->

2. Spring 配置 (applicationContext.xml)

<beans xmlns="https://www.springframework.org/schema/beans"
       xmlns:context="https://www.springframework.org/schema/context"
       xmlns:tx="https://www.springframework.org/schema/tx"
       xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="...">

    <!-- 1. 屬性文件 -->
    <context:property-placeholder location="classpath:db.properties"/>

    <!-- 2. 數據源 (Druid) -->
    <bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource" destroy-method="close">
        <property name="driverClassName" value="${driver}"/>
        <property name="url" value="${url}"/>
        <property name="username" value="${username}"/>
        <property name="password" value="${password}"/>
    </bean>

    <!-- 3. SqlSessionFactoryBean (核心整合點) -->
    <bean id="sqlSessionFactory" class="org.mybatis.spring.SqlSessionFactoryBean">
        <property name="dataSource" ref="dataSource"/>
        <property name="configLocation" value="classpath:MyBatisCfg.xml"/>
        <property name="mapperLocations" value="classpath:com/zhangguo/Spring61/mapping/*.xml"/>
    </bean>

    <!-- 4. 掃描 Mapper 接口自動創建代理 (最推薦方式) -->
    <bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
        <property name="basePackage" value="com.zhangguo.Spring61.mapping"/>
        <property name="sqlSessionFactoryBeanName" value="sqlSessionFactory"/>
    </bean>

    <!-- 5. 事務管理器 -->
    <bean id="transactionManager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager">
        <property name="dataSource" ref="dataSource"/>
    </bean>
    <tx:annotation-driven transaction-manager="transactionManager"/>

    <!-- 6. 掃描 Service/DAO 組件 -->
    <context:component-scan base-package="com.zhangguo.Spring61"/>
</beans>

3. web.xml 載入 Spring 容器

<context-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath:applicationContext.xml</param-value>
</context-param>
<listener>
    <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class>
</listener>

4. Service 層使用 (注入 Mapper 接口)

@Service
public class BookTypeService {
    @Autowired
    private BookTypeDAO bookTypeDAO; // Spring 自動注入 Mapper 代理

    @Transactional(readOnly = true)
    public List<BookType> getAll() {
        return bookTypeDAO.getAllBookTypes();
    }
}

關鍵整合點總結

常見問題與解決

• Mapper 接口無法注入：檢查 MapperScannerConfigurer.basePackage、namespace 是否為接口全限定名
• 事務不生效：檢查 @Transactional 在 public 方法上、tx:annotation-driven 已配置、異常類型默認僅回滾 RuntimeException
• XML 找不到：mapperLocations 路徑匹配、資源文件打包輸出 (pom.xml <resources>)
• 類型別名失效：typeAliases 包掃描、實體類有無參構造器

總結

Spring 整合 MyBatis 核心三步走：**配置 DataSource → 定義 SqlSessionFactoryBean (關聯 DataSource + MyBatis 配置 + Mapper XML) → 掃描 Mapper 接口生成代理**。採用 MapperScannerConfigurer 消除手動 DAO 實現類，配合 @Transactional 聲明式事務，實現極簡數據訪問層。Maven 規範目錄結構 + Druid 連接池 + 外部化配置，構建出生產級項目骨架。