SpringBoot集成Mybatisgn C3P0

对应的目录结构

1.添加依赖

<!-- 添加对mybatis 的依赖 -->
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>1.1.1</version>
        </dependency>

        <!-- 添加对JDBC 的支持 -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jdbc</artifactId>
        </dependency>

        <!-- 添加数据库驱动 -->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>

        <!-- 添加c3p0 数据源 -->
        <dependency>
            <groupId>c3p0</groupId>
            <artifactId>c3p0</artifactId>
            <version>0.9.1.2</version>
        </dependency>

2.配置数据源与SqlSessionFactory

2.1通过application.properties 配置文件进行配置

# 设置数据库相关
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/springboot
spring.datasource.username=root
spring.datasource.password=1234

# 设置c3p0 数据源
spring.datasource.type=com.mchange.v2.c3p0.ComboPooledDataSource

# 设置MyBatis mapper的别名所在的包
mybatis.type-aliases-package=com.jas.mapper
# 设置mapper 接口对应XMl 配置文件的路径
mybatis.mapper-locations=classpath:mapperConfig/*.xml

2.2 通过配置类进行配置

 application.properties配置文件设置相关变量

# 设置数据库相关属性
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.datasource.url=jdbc:mysql://localhost:3306/springboot
spring.datasource.username=root
spring.datasource.password=1234

# 设置，mapper 接口路径，mapper 接口对应的xml 配置文件
mapper.package.path=com.jas.mapper
mapper.xml.config.path=/mapperConfig/*.xml

DataSourceConfiguration类配置c3p0 数据源

@SpringBootConfiguration
public class DataSourceConfiguration {

    @Value("${spring.datasource.driver-class-name}")
    private String jdbcDriver;
    @Value("${spring.datasource.url}")
    private String jdbcUrl;
    @Value("${spring.datasource.username}")
    private String jdbcUser;
    @Value("${spring.datasource.password}")
    private String jdbcPassword;

    @Bean
    public DataSource createDataSource() throws PropertyVetoException {
        ComboPooledDataSource dataSource = new ComboPooledDataSource();

        dataSource.setDriverClass(jdbcDriver);
        dataSource.setJdbcUrl(jdbcUrl);
        dataSource.setUser(jdbcUser);
        dataSource.setPassword(jdbcPassword);
        // 关闭连接后不自动提交
        dataSource.setAutoCommitOnClose(false);

        return dataSource;
    }
}

SqlSessionFactoryBean类配置SqlSessionFactory

@SpringBootConfiguration
public class SessionFactoryConfiguration {

    @Value("${mapper.xml.config.path}")
    private String mapperXMLConfigPath;
    @Value("${mapper.package.path}")
    private String mapperPackagePath;
    @Autowired
    private DataSource dataSource;

    @Bean
    public SqlSessionFactoryBean createSqlSessionFactory() throws IOException {
        SqlSessionFactoryBean sqlSessionFactoryBean = new SqlSessionFactoryBean();
        PathMatchingResourcePatternResolver resolver = new PathMatchingResourcePatternResolver();
        String packageXMLConfigPath = PathMatchingResourcePatternResolver.CLASSPATH_ALL_URL_PREFIX + mapperXMLConfigPath;

        // 设置mapper 对应的XML 文件的路径
        sqlSessionFactoryBean.setMapperLocations(resolver.getResources(packageXMLConfigPath));
        // 设置数据源
        sqlSessionFactoryBean.setDataSource(dataSource);
        // 设置mapper 接口所在的包
        sqlSessionFactoryBean.setTypeAliasesPackage(mapperPackagePath);

        return sqlSessionFactoryBean;
    }
}

3.编写代码 

user类

public class User {

    private Integer userId;
    private String username;
    private Integer age;
    private char gender;

    /** 省略get 与set 方法*/
}

UserMapper类

/** 只定义了一个简单的测试方法*/
@Mapper
public interface UserMapper {

    User getUser(Integer id);
}

userMapper.xml配置文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.jas.mapper.UserMapper">
    <select id="getUser" resultType="com.jas.domain.User">
        SELECT * FROM user WHERE userId = #{userId}
    </select>
</mapper>

4.编写测试的Controller

@RestController
public class UserController {

    @Autowired
    private UserMapper userMapper;

    @GetMapping("/user/{userId}")
    public User getUser(@PathVariable Integer userId){
        User user = userMapper.getUser(userId);
        return user;
    }
}

5.入口类代码(验证c3p0 数据源是否生效)

/** 注意：入口类要能扫描到对应的Bean*/
@SpringBootApplication
public class App {

    public static void main(String[] args) {

        ConfigurableApplicationContext context = SpringApplication.run(App.class, args);
        DataSource dataSource = context.getBean(DataSource.class);

        System.out.println(dataSource.getClass());
    }
}

6.测试结果

控制台输出：可以看出c3p0 数据源已经生效 

浏览器访问测试的Controller

这篇博文记录基于XML 配置文件的MyBatis 使用步骤。如果是基于注解的话，直接在对应的mapper 接口方法上加上对应的注解即可。

PS ：打印SQL 日志

只需要在application.properties 配置文件中设置logging.level.包名=debug即可

# com.jas.mapper是mapper 接口所在的包
logging.level.com.jas.mapper=debug

当访问测试Controller时，控制台会输出SQL 语句 

 

博文参考自https://blog.youkuaiyun.com/codejas/article/details/79334545