目录
(一)、数据源的自动配置-HikariDataSource
1、导入JDBC场景
2、分析自动配置
3、修改配置项
4、测试
(二)、使用Druid数据源
1、druid官方github地址
2、自定义方式
3、使用官方starter方式
(一)、数据源的自动配置-HikariDataSource
1、导入JDBC场景
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jdbc</artifactId>
        </dependency>
         

数据库驱动?
为什么导入JDBC场景,官方不导入驱动?官方不知道我们接下要操作什么数据库。
注意:数据库版本要和驱动版本对应
默认版本:<mysql.version>8.0.22</mysql.version>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
<!--            <version>5.1.49</version>-->
        </dependency>
想要修改版本
1、直接依赖引入具体版本(maven的就近依赖原则)
2、重新声明版本(maven的属性的就近优先原则)
    <properties>
        <java.version>1.8</java.version>
        <mysql.version>5.1.49</mysql.version>
    </properties> 
2、分析自动配置
1、自动配置的类
- DataSourceAutoConfiguration : 数据源的自动配置
 
-  
  
- 修改数据源相关的配置:spring.datasource
 - 数据库连接池的配置,是自己容器中没有DataSource才自动配置的
 - 底层配置好的连接池是:HikariDataSource
 
 
	@Configuration(proxyBeanMethods = false)
	@Conditional(PooledDataSourceCondition.class)
	@ConditionalOnMissingBean({ DataSource.class, XADataSource.class })
	@Import({ DataSourceConfiguration.Hikari.class, DataSourceConfiguration.Tomcat.class,
			DataSourceConfiguration.Dbcp2.class, DataSourceConfiguration.OracleUcp.class,
			DataSourceConfiguration.Generic.class, DataSourceJmxConfiguration.class })
	protected static class PooledDataSourceConfiguration 
- DataSourceTransactionManagerAutoConfiguration: 事务管理器的自动配置
 - JdbcTemplateAutoConfiguration: JdbcTemplate的自动配置,可以来对数据库进行crud
 
-  
  
- 可以修改这个配置项@ConfigurationProperties(prefix = "spring.jdbc") 来修改JdbcTemplate
 - JdbcTemplate;容器中有这个组件
 
 
- JndiDataSourceAutoConfiguration: jndi的自动配置
 - XADataSourceAutoConfiguration: 分布式事务相关的
 
3、修改配置项
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/db_account
    username: root
    password: 123456
    driver-class-name: com.mysql.jdbc.Driver 
4、测试
@Slf4j
@SpringBootTest
class Boot05WebAdminApplicationTests {
    @Autowired
    JdbcTemplate jdbcTemplate;
    @Test
    void contextLoads() {
        Long aLong = jdbcTemplate.queryForObject("select count(*) from account_tbl", Long.class);
        log.info("记录总数:{}",aLong);
    }
} 
(二)、使用Druid数据源
1、druid官方github地址
GitHub - alibaba/druid: 阿里云计算平台DataWorks(https://help.aliyun.com/document_detail/137663.html) 团队出品,为监控而生的数据库连接池
整合第三方技术的两种方式
- 自定义
 - 找starter
 
2、自定义方式
1、创建数据源
    导入druid的依赖
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.17</version>
        </dependency>
 
2、StatViewServlet
StatViewServlet的用途包括:
- 提供监控信息展示的html页面
 - 提供监控信息的JSON API
 
    <servlet>
		<servlet-name>DruidStatView</servlet-name>
		<servlet-class>com.alibaba.druid.support.http.StatViewServlet</servlet-class>
	</servlet>
	<servlet-mapping>
		<servlet-name>DruidStatView</servlet-name>
		<url-pattern>/druid/*</url-pattern>
	</servlet-mapping>
 
 
3、StatFilter
 用于统计监控信息;如SQL监控、URI监控
  
需要给数据源中配置如下属性;可以允许多个filter,多个用,分割;如:
<property name="filters" value="stat,slf4j" /> 
系统中所有filter:
|   别名  |   Filter类名  | 
|   default  |   com.alibaba.druid.filter.stat.StatFilter  | 
|   stat  |   com.alibaba.druid.filter.stat.StatFilter  | 
|   mergeStat  |   com.alibaba.druid.filter.stat.MergeStatFilter  | 
|   encoding  |   com.alibaba.druid.filter.encoding.EncodingConvertFilter  | 
|   log4j  |   com.alibaba.druid.filter.logging.Log4jFilter  | 
|   log4j2  |   com.alibaba.druid.filter.logging.Log4j2Filter  | 
|   slf4j  |   com.alibaba.druid.filter.logging.Slf4jLogFilter  | 
|   commonlogging  |   com.alibaba.druid.filter.logging.CommonsLogFilter  | 
慢SQL记录配置
<bean id="stat-filter" class="com.alibaba.druid.filter.stat.StatFilter">
    <property name="slowSqlMillis" value="10000" />
    <property name="logSlowSql" value="true" />
</bean>
使用 slowSqlMillis 定义慢SQL的时长 
上面的配置也可以通过配置类直接编码实现
@Configuration
public class MyDatasourceConfig {
    @ConfigurationProperties("spring.datasource")
    @Bean
    public DataSource dataSource() throws SQLException {
        DruidDataSource druidDataSource = new DruidDataSource();
        //加入监控功能
        druidDataSource.setFilters("stat,wall");
        return druidDataSource;
    }
    /*
     * 配置Druid的监控页功能
     */
    @Bean
    public ServletRegistrationBean statViewServlet() {
        StatViewServlet statViewServlet = new StatViewServlet();
        ServletRegistrationBean<StatViewServlet> servletServletRegistrationBean = new ServletRegistrationBean<StatViewServlet>(statViewServlet,"/druid/*");
        servletServletRegistrationBean.addInitParameter("loginUsername","admin");
        servletServletRegistrationBean.addInitParameter("loginPassword","123456");
        return servletServletRegistrationBean;
    }
    /*
     * webStatFilter 用于采集web-jdbc关联监控的数据
     */
    @Bean
    public FilterRegistrationBean webStatFilter() {
        WebStatFilter webStatFilter = new WebStatFilter();
        FilterRegistrationBean<WebStatFilter> webStatFilterFilterRegistrationBean = new FilterRegistrationBean<>(webStatFilter);
        webStatFilterFilterRegistrationBean.setUrlPatterns(Arrays.asList("/*"));
        webStatFilterFilterRegistrationBean.addInitParameter("exclusions","*.js,*.css,/druid/*");
        return webStatFilterFilterRegistrationBean;
    }
} 
3、使用官方starter方式
1、引入druid-starter
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.17</version>
        </dependency> 
2、分析自动配置
- 扩展配置项 spring.datasource.druid
 - DruidSpringAopConfiguration.class, 监控SpringBean的;配置项:spring.datasource.druid.aop-patterns
 - DruidStatViewServletConfiguration.class, 监控页的配置:spring.datasource.druid.stat-view-servlet;默认开启
 - DruidWebStatFilterConfiguration.class, web监控配置;spring.datasource.druid.web-stat-filter;默认开启
 - DruidFilterConfiguration.class}) 所有Druid自己filter的配置
 
    private static final String FILTER_STAT_PREFIX = "spring.datasource.druid.filter.stat";
    private static final String FILTER_CONFIG_PREFIX = "spring.datasource.druid.filter.config";
    private static final String FILTER_ENCODING_PREFIX = "spring.datasource.druid.filter.encoding";
    private static final String FILTER_SLF4J_PREFIX = "spring.datasource.druid.filter.slf4j";
    private static final String FILTER_LOG4J_PREFIX = "spring.datasource.druid.filter.log4j";
    private static final String FILTER_LOG4J2_PREFIX = "spring.datasource.druid.filter.log4j2";
    private static final String FILTER_COMMONS_LOG_PREFIX = "spring.datasource.druid.filter.commons-log";
    private static final String FILTER_WALL_PREFIX = "spring.datasource.druid.filter.wall"; 
3、配置示例
spring:
  datasource:
    url: jdbc:mysql://localhost:3306/db_account
    username: root
    password: 123456
    driver-class-name: com.mysql.jdbc.Driver
    druid:
      aop-patterns: com.atguigu.admin.*  #监控SpringBean
      filters: stat,wall     # 底层开启功能,stat(sql监控),wall(防火墙)
      stat-view-servlet:   # 配置监控页功能
        enabled: true
        login-username: admin
        login-password: admin
        resetEnable: false
      web-stat-filter:  # 监控web
        enabled: true
        urlPattern: /*
        exclusions: '*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*'
      filter:
        stat:    # 对上面filters里面的stat的详细配置
          slow-sql-millis: 1000
          logSlowSql: true
          enabled: true
        wall:
          enabled: true
          config:
            drop-table-allow: false
 
SpringBoot配置示例
https://github.com/alibaba/druid/tree/master/druid-spring-boot-starter
配置项列表https://github.com/alibaba/druid/wiki/DruidDataSource%E9%85%8D%E7%BD%AE%E5%B1%9E%E6%80%A7%E5%88%97%E8%A1%A8



















