Spring 整合 Mybatis（注解方式）_spring 用例

一、项目说明

1.1 项目结构

1.2 项目依赖

除了 Spring 相关依赖外，还需要导入数据库驱动和对应的 MyBatis 依赖：

<!--jdbc 相关依赖包-->
<dependency>
    <groupId>org.springframework</groupId>
    <artifactId>spring-jdbc</artifactId>
    <version>${spring-base-version}</version>
</dependency>
<dependency>
    <groupId>mysql</groupId>
    <artifactId>mysql-connector-java</artifactId>
    <version>8.0.13</version>
</dependency>
<dependency>
    <groupId>com.oracle</groupId>
    <artifactId>ojdbc6</artifactId>
    <version>11.2.0.3.0</version>
</dependency>
<!--mybatis 依赖包-->
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis-spring</artifactId>
    <version>1.3.2</version>
</dependency>
<dependency>
    <groupId>org.mybatis</groupId>
    <artifactId>mybatis</artifactId>
    <version>3.4.6</version>
</dependency>

二、整合 MyBatis

2.1 数据库配置

在 resources 文件夹下新建数据库配置文件 jdbc.properties：

# mysql 数据库配置
mysql.driverClassName=com.mysql.jdbc.Driver
mysql.url=jdbc:mysql://localhost:3306/mysql
mysql.username=root
mysql.password=root
# oracle 数据库配置
oracle.driverClassName=oracle.jdbc.driver.OracleDriver
oracle.url=jdbc:oracle:thin:@//IP 地址:端口号/数据库实例名
oracle.username=用户名
oracle.password=密码

@Configuration
@PropertySource(value = "classpath:mysql.properties")
@Data
public class DataSourceConfig {
    @Value("${mysql.driverClassName}")
    private String driverClassName;
    @Value("${mysql.url}")
    private String url;
    @Value("${mysql.username}")
    private String username;
    @Value("${mysql.password}")
    private String password;
}

2.2 配置数据源

配置数据源、MyBatis 会话工厂和事务管理器：

@Configuration
@EnableTransactionManagement // 开启声明式事务处理 等价于 xml 中<tx:annotation-driven/>
@ComponentScan(basePackages = {"com.heibaiying.*"})
public class DatabaseConfig {
    /* @Autowired
     * private DataSourceConfig sourceConfig;
     * 不要采用这种方式注入 DataSourceConfig,由于类的加载顺序影响会报空指针异常
     * 最好的方式是在 DriverManagerDataSource 构造中采用参数注入
     */
    /**
     * 配置数据源
     */
    @Bean
    public DriverManagerDataSource dataSource(DataSourceConfig sourceConfig) {
        DriverManagerDataSource dataSource = new DriverManagerDataSource();
        dataSource.setDriverClassName(sourceConfig.getDriverClassName());
        dataSource.setUrl(sourceConfig.getUrl());
        dataSource.setUsername(sourceConfig.getUsername());
        dataSource.setPassword(sourceConfig.getPassword());
        return dataSource;
    }
    /**
     * 配置 mybatis 会话工厂
     *
     * @param dataSource 这个参数的名称需要保持和上面方法名一致 才能自动注入,因为
     *                   采用 @Bean 注解生成的 bean 默认采用方法名为名称，当然也可以通过name属性自行指定
     */
    @Bean
    public SqlSessionFactoryBean sessionFactoryBean(DriverManagerDataSource dataSource) throws IOException {
        SqlSessionFactoryBean sessionFactoryBean = new SqlSessionFactoryBean();
        sessionFactoryBean.setDataSource(dataSource);
        PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
        sessionFactoryBean.setMapperLocations(resolver.getResources("classpath*:/mappers/**/*.xml"));
        sessionFactoryBean.setConfigLocation(resolver.getResource("classpath:mybatisConfig.xml"));
        return sessionFactoryBean;
    }
    /**
     * 配置 mybatis 会话工厂
     */
    @Bean
    public MapperScannerConfigurer MapperScannerConfigurer() {
        MapperScannerConfigurer configurer = new MapperScannerConfigurer();
        configurer.setSqlSessionFactoryBeanName("sessionFactoryBean");
        configurer.setBasePackage("com.heibaiying.dao");
        return configurer;
    }
    /**
     * 定义事务管理器
     */
    @Bean
    public DataSourceTransactionManager transactionManager(DriverManagerDataSource dataSource) {
        DataSourceTransactionManager manager = new DataSourceTransactionManager();
        manager.setDataSource(dataSource);
        return manager;
    }
}

2.3 MyBatis 配置

新建mybtais配置文件，按照需求配置额外参数，更多 settings 配置项可以参考官方文档

<?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">
<!-- mybatis 配置文件 -->
<configuration>
    <settings>
        <!-- 开启驼峰命名 -->
        <setting name="mapUnderscoreToCamelCase" value="true"/>
        <!-- 打印查询 sql -->
        <setting name="logImpl" value="STDOUT_LOGGING"/>
    </settings>
</configuration>
<!--更多settings配置项可以参考官方文档: <a href="http://www.mybatis.org/mybatis-3/zh/configuration.html"/>-->

2.4 数据查询

新建查询接口及其实现类，以下示例分别查询的是 MySQL 和 Oracle 中的字典表：

public interface MysqlDao {
    List<Relation> get();
}

<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.heibaiying.dao.MysqlDao">
    <select id="queryById" resultType="com.heibaiying.bean.Relation">
        SELECT help_keyword_id AS id,name
        FROM HELP_KEYWORD
        WHERE HELP_KEYWORD_ID = #{id}
    </select>
</mapper>

public interface OracleDao {
    List<Flow> queryById(long id);
}

<!DOCTYPE mapper
        PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN"
        "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.heibaiying.dao.OracleDao">
    <select id="queryById" resultType="com.heibaiying.bean.Flow">
        select * from APEX_030200.WWV_FLOW_CALS where ID = #{id}
    </select>
</mapper>

2.5 测试查询

新建测试类进行测试：

@RunWith(SpringRunner.class)
@ContextConfiguration(classes = {DatabaseConfig.class})
public class MysqlDaoTest {
    @Autowired
    private MysqlDao mysqlDao;
    @Test
    public void get() {
        List<Relation> relations = mysqlDao.queryById("691");
        if (relations != null) {
            for (Relation relation : relations) {
                System.out.println(relation.getId() + " " + relation.getName());
            }
        }
    }
}

@RunWith(SpringRunner.class)
@ContextConfiguration(classes = {DatabaseConfig.class})
public class OracleDaoTest {
    @Autowired
    private OracleDao oracleDao;
    @Test
    public void get() {
        List<Flow> flows = oracleDao.queryById(217584603977429772L);
        if (flows != null) {
            for (Flow flow : flows) {
                System.out.println(flow.getId() + " " + flow.getPlugId());
            }
        }
    }
}