Springboot—数据访问

目录

SQL：

自动配置分析：

  DataSourceAutoConfiguration：数据源的自动配置

JdbcTemplateAutoConfiguration:

Druid数据源：

DruidDataSourceAutoConfigure

然后我们看下关键的DruidStatProperties：

DruidDataSourceAutoConfigure:

 yml全部：

自定义实现监控页与监控功能：

SQL：

   1.首先导入JDBC场景：

org.springframework.boot spring-boot-starter-data-jdbc

2.然后我们导入驱动（数据库版本尽量与驱动版本保持一致）：

mysql mysql-connector-java 5.1.49

自动配置分析：

  DataSourceAutoConfiguration：数据源的自动配置

@EnableConfigurationProperties({DataSourceProperties.class})@import({DataSourcePoolmetadataProvidersConfiguration.class, DataSourceInitializationConfiguration.class})public class DataSourceAutoConfiguration { public DataSourceAutoConfiguration() { }

  可以发现底层默认配置好的连接池为：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

然后我们看看被数据源自动配置所绑定的DataSourceProperties：

@ConfigurationProperties( prefix = "spring.datasource")public class DataSourceProperties implements BeanClassLoaderAware, InitializingBean { private ClassLoader classLoader; private boolean generateUniqueName = true; private String name; private Class<? extends DataSource> type; private String driverClassName; private String url; private String username; private String password; private String jndiName;

所以说我们可以用yml对数据源驱动进行配置（以spring.datasource.xxx进行配置）

spring: datasource: url: jdbc:mysql://localhost:3306/db_account username: root password: 123456 driver-class-name: com.mysql.jdbc.Driver

JdbcTemplateAutoConfiguration:

  JdbcTemplate的自动配置，里面有对数据库的crud；

@Configuration( proxyBeanMethods = false)@ConditionalOnClass({DataSource.class, JdbcTemplate.class})@ConditionalOnSingleCandidate(DataSource.class)@AutoConfigureAfter({DataSourceAutoConfiguration.class})@EnableConfigurationProperties({JdbcProperties.class})@import({JdbcTemplateConfiguration.class, NamedParameterJdbcTemplateConfiguration.class})public class JdbcTemplateAutoConfiguration { public JdbcTemplateAutoConfiguration() { }}

JdbcProperties中绑定了jdbc操作（以spring.jdbc.xxx在yml中配置）：

@ConfigurationProperties( prefix = "spring.jdbc")public class JdbcProperties { private final JdbcProperties.Template template = new JdbcProperties.Template(); public JdbcProperties() { }

扩：

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@Bean@Primary 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

测试：

@Slf4j@SpringBootTestclass Boot05WebAdminApplicationTests { @Autowired JdbcTemplate jdbcTemplate; @Test void contextLoads() {// jdbcTemplate.queryForObject("select * from account_tbl")// jdbcTemplate.queryForList("select * from account_tbl",) Long aLong = jdbcTemplate.queryForObject("select count(*) from account_tbl", Long.class); log.info("记录总数：{}",aLong); }}

Druid数据源：

  这里放上druid的文档

https://github.com/alibaba/druid/wiki/%E5%B8%B8%E8%A7%81%E9%97%AE%E9%A2%98English https://github.com/alibaba/druid/wiki/FAQ

  在springboot中，我们不能像之前那样导入bean来配置数据源，或者在web.xml中通过servlet映射来配置功能了；

而是自定义Configuration，注册组件的方式或者通过yaml配置的方式来配置数据源增加配置功能；

DruidDataSourceAutoConfigure

 可以发现它是要在DataSourceAutoConfiguration之前执行的，因为DataSourceAutoConfiguration里面配置了默认数据源，所以要先执行；

@Configuration@ConditionalOnClass({DruidDataSource.class})@AutoConfigureBefore({DataSourceAutoConfiguration.class})@EnableConfigurationProperties({DruidStatProperties.class, DataSourceProperties.class})@import({DruidSpringAopConfiguration.class, DruidStatViewServletConfiguration.class, DruidWebStatFilterConfiguration.class, DruidFilterConfiguration.class})public class DruidDataSourceAutoConfigure { private static final Logger LOGGER = LoggerFactory.getLogger(DruidDataSourceAutoConfigure.class); public DruidDataSourceAutoConfigure() { } @Bean( initMethod = "init" ) @ConditionalOnMissingBean public DataSource dataSource() { LOGGER.info("Init DruidDataSource"); return new DruidDataSourceWrapper(); }}

然后我们看下关键的DruidStatProperties：

里面能够配置的东西有很多：以spring.datasource.druid为前缀，实现aoppatterns（监控springBean）；还可以开启filters：stat,wall,slf4j等功能（全局性的，不是具体的）

大致有两个功能：1：StatViewServlet:配置监控页功能；2：WebStatFilter:监控web

@ConfigurationProperties("spring.datasource.druid")public class DruidStatProperties { private String[] aopPatterns; private DruidStatProperties.StatViewServlet statViewServlet = new DruidStatProperties.StatViewServlet(); private DruidStatProperties.WebStatFilter webStatFilter = new DruidStatProperties.WebStatFilter(); public DruidStatProperties() { } public String[] getAopPatterns() { return this.aopPatterns; } public void setAopPatterns(String[] aopPatterns) { this.aopPatterns = aopPatterns; } public DruidStatProperties.StatViewServlet getStatViewServlet() { return this.statViewServlet; } public void setStatViewServlet(DruidStatProperties.StatViewServlet statViewServlet) { this.statViewServlet = statViewServlet; } public DruidStatProperties.WebStatFilter getWebStatFilter() { return this.webStatFilter; } public void setWebStatFilter(DruidStatProperties.WebStatFilter webStatFilter) { this.webStatFilter = webStatFilter; } public static class WebStatFilter { private boolean enabled; private String urlPattern; private String exclusions; private String sessionStatMaxCount; private String sessionStatEnable; private String principalSessionName; private String principalcookieName; private String profileEnable;} public static class StatViewServlet { private boolean enabled; private String urlPattern; private String allow; private String deny; private String loginUsername; private String loginPassword; private String resetEnable;}

 在yml中实现对statviewServlet与webstatFilter的全局配置：

spring: datasource: url: jdbc:mysql://localhost:3306/db_account username: Wuyuhang password: 2002514wyh11 driver-class-name: com.mysql.jdbc.Driver druid: filters: stat,wall,slf4j #开启监控和防火墙and日志功能 stat-view-servlet: admin login-password: 123456 reset-enable: false#监控web应用 web-stat-filter: enabled: true url-pattern: @Bean public ServletRegistrationBean statViewServlet(){// statViewServlet就是监控视图响应 StatViewServlet statViewServlet = new StatViewServlet(); ServletRegistrationBean registrationBean = new ServletRegistrationBean<>(statViewServlet, "/druid @Bean public FilterRegistrationBean webStatFilter(){ WebStatFilter webStatFilter = new WebStatFilter(); FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean<>(webStatFilter); filterRegistrationBean.setUrlPatterns(Arrays.asList("/*")); filterRegistrationBean.addInitParameter("exclusions","*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*"); return filterRegistrationBean; }