SpringBoot默认使用HikariDataSource数据源方式

spring.datasource.type=com.zaxxer.hikari.HikariDataSource

@RunWith(SpringRunner.class)
@SpringBootTest
public class HorseApplicationTests {
    /**
     * Spring Boot 默认已经配置好了数据源，程序员可以直接 DI 注入然后使用即可
     */
    @Resource
    DataSource dataSource;
    
    @Test
    public void contextLoads() throws SQLException {
        System.out.println("数据源>>>>>>" + dataSource.getClass());
    }

com.zaxxer.hikari.HikariConfig
private static final long IDLE_TIMEOUT = MINUTES.toMillis(10);
private static final long MAX_LIFETIME = MINUTES.toMillis(30);
private static final int DEFAULT_POOL_SIZE = 10;
private static boolean unitTest = false;

// Properties changeable at runtime through the HikariConfigMXBean
//
private volatile long connectionTimeout;
private volatile long validationTimeout;
private volatile long idleTimeout;
private volatile long leakDetectionThreshold;
private volatile long maxLifetime;
private volatile int maxPoolSize;
private volatile int minIdle;
private volatile String username;
private volatile String password;