第一章：数据自动管理

1. 引入 JDBC 的依赖和 SpringBoot 的应用场景：

   <dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-jdbc</artifactId>
   </dependency>
   <dependency><groupId>org.apache.commons</groupId><artifactId>commons-dbcp2</artifactId>
   </dependency><dependency><groupId>mysql</groupId><artifactId>mysql-connector-java</artifactId><scope>runtime</scope>
   </dependency>

2. 创建 application.yaml 进行配置：

   spring:datasource:username: rootpassword: rooturl: jdbc:mysql://localhost:3306/boot_demodriver-class-name: com.mysql.jdbc.Drivertype: com.zaxxer.hikari.HikariDataSource

   1. 在默认情况下，数据链接可以使用 DataSource 池进行自动配置
   2. Hikari 可用，SpringBoot 将使用它
   3. Commons DBCP2 可用，我们将使用它 
   4. 也可以指定数据源配置，通过 type 来选取使用哪种数据源

      spring:datasource:username: rootpassword: rooturl: jdbc:mysql://localhost:3306/boot_demodriver-class-name: com.mysql.jdbc.Drivertype: com.zaxxer.hikari.HikariDataSource# type: org.apache.commons.dbcp2.BasicDataSource

3. 设置 druid 数据源：

   <dependency><groupId>com.alibaba</groupId><artifactId>druid</artifactId><version>1.0.9</version>
   </dependency>
   <dependency><groupId>log4j</groupId><artifactId>log4j</artifactId><version>1.2.15</version>
   </dependency>

   1. 修改 application.yaml 文件中：

      connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

   2. 在 application.yaml 文件中加入：

      spring:datasource:username: rootpassword: rooturl: jdbc:mysql://localhost:3306/boot_demodriver-class-name: com.mysql.jdbc.Drivertype: com.alibaba.druid.pool.DruidDataSourceinitialSize: 5minIdle: 5maxActive: 20maxWait: 60000timeBetweenEvictionRunsMillis: 60000minEvictableIdleTimeMillis: 300000validationQuery: SELECT 1 FROM DUALtestWhileIdle: truetestOnBorrow: falsetestOnReturn: falsepoolPreparedStatements: truefilters: stat,wall,log4jmaxPoolPreparedStatementPerConnectionSize: 20useGlobalDataSourceStat: trueconnectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=500

   3. 创建数据源注册类：

      java">@Configuration
      public class DruidConfig {@ConstructorProperties(prefix="spring.datasource")@Beanpublic DataSource dataSource(){return new DruidDataSource;}
      }

   4. 配置 druid 运行期监控

      java">@Configuration
      public class DruidConfig {@ConstructorProperties(prefix="spring.datasource")@Beanpublic DataSource dataSource(){return new DruidDataSource;}@Beanpublic ServletRegistrationBean statViewServlet(){ServletRegistrationBean bean = new ServletRegistrationBean(new StatViewServlet(),"/druid/*");Map<String,String> initParams = new HashMap<>();initParams.put("loginUsername","root");initParams.put("loginPassword","root");initParams.put("allow","");//默认就是允许所有访问initParams.put("deny","192.168.15.21");bean.setInitParameters(initParams);return bean;}//2、配置一个web监控的filter@Beanpublic FilterRegistrationBean webStatFilter(){FilterRegistrationBean bean;bean = new FilterRegistrationBean();bean.setFilter(new WebStatFilter());Map<String,String> initParams = new HashMap<>();initParams.put("exclusions","*.js,*.css,/druid/*");bean.setInitParameters(initParams);bean.setUrlPatterns(Arrays.asList("/*"));return bean;}
      }

   5. 打开监控页面：http://localhost:8080/druid

第二章：SpringBoot 整合 JDBCTemplate

1. 创建表：

   
   SET FOREIGN_KEY_CHECKS=0;-- ----------------------------
   -- Table structure for tx_user
   -- ----------------------------
   DROP TABLE IF EXISTS `tx_user`;
   CREATE TABLE `tx_user` (`username` varchar(10) DEFAULT NULL,`userId` int(10) NOT NULL,`password` varchar(10) DEFAULT NULL,PRIMARY KEY (`userId`)
   ) ENGINE=InnoDB DEFAULT CHARSET=utf8;

2. 创建 Controller：

   java">public class TestController {@AutowiredJdbcTemplate jdbcTemplate;@ResponseBody@RequestMapping("/query")public List<Map<String, Object>> query(){List<Map<String, Object>> maps = jdbcTemplate.queryForList("SELECT * FROM tx_user");return maps;}

3. 启动 SpringBoot 访问：http://localhost:8080/query
4. SpringBoot 中提供了 jdbcTemplateAutoConfiguration 的自动配置

   java">org.springframework.boot.autoconfigure.jdbc.JdbcTemplateAutoConfiguration

5. jdbcTemplateAutoConfiguration 源码：