AliDruid 配置方法

（1）在实际工作中，由于 HikariCP 和 Druid 应该各有千秋，会发现偏向于监控，有很多国内开发 者使用频次最高的 AliDruid，我们来看看看如何配置。

<!--druid--><dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.1.5</version></dependency>

（2）一样的思路，我们打开 DruidDataSourceAutoConfigure 配置类。

@Configuration
@ConditionalOnClass(com.alibaba.druid.pool.DruidDataSource.class)
@AutoConfigureBefore(DataSourceAutoConfiguration.class)
@EnableConfigurationProperties({DruidStatProperties.class, DataSourceProperties.class})
@Import({DruidSpringAopConfiguration.class,DruidStatViewServletConfiguration.class,DruidWebStatFilterConfiguration.class,DruidFilterConfiguration.class})
public class DruidDataSourceAutoConfigure {@Bean@ConditionalOnMissingBeanpublic DataSource dataSource() {return new DruidDataSourceWrapper();}/*** Register the {@link DataSourcePoolMetadataProvider} instances to support DataSource metrics.** @see DataSourcePoolMetadataProvidersConfiguration*/@Beanpublic DataSourcePoolMetadataProvider druidDataSourcePoolMetadataProvider() {return new DataSourcePoolMetadataProvider() {@Overridepublic DataSourcePoolMetadata getDataSourcePoolMetadata(DataSource dataSource) {if (dataSource instanceof DruidDataSource) {return new DruidDataSourcePoolMetadata((DruidDataSource) dataSource);}return null;}};}
}

我们发现 Druid 继承了 DataSourceProperties 的配置。

（3）我们打开 DruidDataSourceWrapper：

@ConfigurationProperties("spring.datasource.druid")
class DruidDataSourceWrapper extends DruidDataSource implements InitializingBean {@Autowiredprivate DataSourceProperties basicProperties;@Overridepublic void afterPropertiesSet() throws Exception {//if not found prefix 'spring.datasource.druid' jdbc properties ,'spring.datasource' prefix jdbc properties will be used.if (super.getUsername() == null) {super.setUsername(basicProperties.determineUsername());}if (super.getPassword() == null) {super.setPassword(basicProperties.determinePassword());}if (super.getUrl() == null) {super.setUrl(basicProperties.determineUrl());}if (super.getDriverClassName() == null) {super.setDriverClassName(basicProperties.determineDriverClassName());}}
......}

发现了 DataSource 的配置方法：

spring.datasource.druid.url=jdbc:mysql://127.0.0.1:3306/test # 或spring.datasource.url= 
spring.datasource.druid.username=jack # 或spring.datasource.username=
spring.datasource.druid.password=jack123 # 或spring.datasource.password=
spring.datasource.druid.driver-class-name=com.mysql.jdbc.Driver #或 spring.datasource.driver-class-name=

（4）如果我们再打开 DruidDataSource 类，就会发现连接池的配置方法：

spring.datasource.druid.initial-size=
spring.datasource.druid.max-active=
spring.datasource.druid.min-idle=
spring.datasource.druid.max-wait=
spring.datasource.druid.pool-prepared-statements=
spring.datasource.druid.max-pool-prepared-statement-per-connection-size= 
spring.datasource.druid.max-open-prepared-statements= #和上面的等价
spring.datasource.druid.validation-query=
spring.datasource.druid.validation-query-timeout=
spring.datasource.druid.test-on-borrow=
spring.datasource.druid.test-on-return=
spring.datasource.druid.test-while-idle=
spring.datasource.druid.time-between-eviction-runs-millis=
spring.datasource.druid.min-evictable-idle-time-millis=
spring.datasource.druid.max-evictable-idle-time-millis=
spring.datasource.druid.filters= #配置多个英文逗号分隔
....//more

如果再继续往上面看 DruidAbstractDataSource，会发现很多默认值。

（5）如果依次打开以下这些类，也会发现 Druid 的更多配置：

@Import({DruidSpringAopConfiguration.class,DruidStatViewServletConfiguration.class,DruidWebStatFilterConfiguration.class,DruidFilterConfiguration.class})

WebStatFilter 配置，说明请参考 Druid Wiki，配置 WebStatFilter：

spring.datasource.druid.web-stat-filter.enabled= #是否启用StatFilter默认值true
spring.datasource.druid.web-stat-filter.url-pattern=

StatViewServlet 配置，说明请参考 Druid Wiki，配置 StatViewServlet：

spring.datasource.druid.stat-view-servlet.enabled= #是否启用StatViewServlet默认值true
spring.datasource.druid.stat-view-servlet.login-username=
spring.datasource.druid.stat-view-servlet.login-password=

Druid的更多配置请参看官方文档吧，只是给大家举例如何一步一步的查看这些配置，而得到如何配置。