DataSourceAutoConfiguration分析
SpringBoot有一个自动配置DataSourceAutoConfiguration 为数据源配置
/META-INF/spring.factories文件找到DataSourceAutoConfiguration配置类
一、先来看下DataSourceAutoConfiguration配置类生效的时机,观察源码发现
@Configuration(proxyBeanMethods = false)
@ConditionalOnClass({
DataSource.class, EmbeddedDatabaseType.class })
@EnableConfigurationProperties(DataSourceProperties.class)
@Import({
DataSourcePoolMetadataProvidersConfiguration.class, DataSourceInitializationConfiguration.class })
在springboot下只有EmbeddedDatabaseType类型是爆红,说明没有相关依赖引入,而它属于spring-jdbc依赖,那么加上(从spring-boot-starter-data-jdbc里面复制的)
<dependency>
<groupId>org.springframework</groupId>
<artifactId>spring-jdbc</artifactId>
<version>5.2.1.RELEASE</version>
<scope>compile</scope>
</dependency>
此时重启项目发现容器中已经有org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration 即此时DataSourceAutoConfiguration生效,但是它仅仅是DataSourceAutoConfiguration这个类被注入容器,要想自动配置数据源
还需要让EmbeddedDatabaseConfiguration或PooledDataSourceConfiguration生效
当引入下面依赖时可以去掉spring-jdb因为spring-boot-starter-data-jdbc里面引入了spring-jdb依赖
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jdbc</artifactId>
</dependency>
DataSourceAutoConfiguration 就会触发自动配置
配置生效时机参考传送门
题外话spring-boot-starter-jdbc 和 spring-boot-starter-data-jdbc 的区别
一、你会发现spring-boot-starter-data-jdbc 依赖下面有spring-boot-starter-jdbc和spring-data-jdbc
而spring-data-jdbc引入了spring-data-commons 其中CrudRepository接口提供了基础增删改查,该接口就在spring-data-commons中。
二、springboot默认的数据源是HikariDataSource,HikariCP依赖位于spring-boot-starter-jdbc下。
上面测试用到的
依赖
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<version>2.2.1.RELEASE</version>
</dependency>
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<scope>runtime</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-jdbc</artifactId>
</dependency>
<dependency>
<groupId>org.projectlombok</groupId>
<artifactId>lombok</artifactId>
<version>1.18.24</version>
</dependency>
</dependencies>
测试类MyBatisPlusBootMain
@SpringBootApplication
public class MyBatisPlusBootMain implements CommandLineRunner, ApplicationContextAware {
Logger logger = LoggerFactory.getLogger(MyBatisPlusBootMain.class);
@Autowired(required = false)
DataSource dataSource;
private ApplicationContext applicationContext;
public static void main(String[] args) {
ApplicationContext run = SpringApplication.run(MyBatisPlusBootMain.class, args);
UsersEntity user01 = run.getBean("user01", UsersEntity.class);
System.out.println(user01);
DataSourceAutoConfiguration dataSourceAutoConfiguration = run.getBean("org.springframework.boot.autoconfigure.jdbc.DataSourceAutoConfiguration", DataSourceAutoConfiguration.class);
System.out.println(dataSourceAutoConfiguration);
}
@Override
public void run(String... args) throws Exception {
System.out.println(">>>>>>>>>>>>>>>>>服务启动执行");
showConnection();
showIOCBean();
}
private void showIOCBean() {
String[] names = this.applicationContext.getBeanDefinitionNames();
for (int i = 0; i < names.length; i++) {
System.out.println(names[i]);
}
}
private void showConnection() throws SQLException {
logger.info("dataSource:{}", dataSource.getClass().getName());
Connection connection = dataSource.getConnection();
logger.info("connection:{}", connection.toString());
}
@Override
public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
this.applicationContext=applicationContext;
}
}
yml
spring:
datasource:
url: jdbc:mysql://localhost:3306/test
username: root
password: 3306
更换默认的数据源改为DruidDataSource
参考:传送门
方法一:
添加依赖
<dependency>
<groupId>com.alibaba</groupId>
<artifactId>druid</artifactId>
<version>1.1.23</version>
</dependency>
yml
spring:
datasource:
url: jdbc:mysql://localhost:3306/bms_test
username: root
password: 3306
type: com.alibaba.druid.pool.DruidDataSource
此时数据源更改为DruidDataSource
方法二:
1 、添加druid依赖
2、创建DataSource的bean,进行相关配置后,返回DruidDataSource
@Bean
public DataSource dataSource() {
DruidDataSource dataSource = new DruidDataSource();
dataSource.setUrl("jdbc:mysql://localhost:3306/bms_test");
dataSource.setUsername("root");
dataSource.setPassword("3306");
return dataSource;
}