通过starter整合Druid

# 500.通过starter整合Druid

本文讲讲如何通过starter的方式，来整合Druid 　　‍

# 引入依赖

在GitHub (opens new window)里，已经有一个starter的目录，我们点下面那个：

‍

然后就可以看到文档了：

‍

我们引入starter，并将之前的Druid依赖注释掉：

<!--        <dependency>-->
<!--            <groupId>com.alibaba</groupId>-->
<!--            <artifactId>druid</artifactId>-->
<!--            <version>1.2.6</version>-->
<!--        </dependency>-->

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.2.6</version>
        </dependency>

1
2
3
4
5
6
7
8
9
10
11

‍

除此之外，将之前的配置类注释掉：

//@Configuration
public class MyDataSourceConfig {

1
2

‍

# 自动配置功能分析

引入后，可以看到其已经引入了Druid，还有日志框架、自动配置：

‍

我们打开这个包，能看到有个自动配置类DruidDataSourceAutoConfigure：

‍

@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();
    }
}

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20

‍

代码分析：

首先@Configuration 说明这是一个配置类
@ConditionalOnClass({DruidDataSource.class}) 说明得有Druid的DataSource，才会生效
@AutoConfigureBefore({DataSourceAutoConfiguration.class}) 说明得在SpringBoot自动配置数据源之前，配置，目的是在官方的数据源之前，注入Druid自己的数据源
@EnableConfigurationProperties 还是和配置文件中spring.datasource开头的配置进行绑定，额外的配置则是spring.datasource.druid
还@Import了如下类：
- DruidSpringAopConfiguration：监控Spring相关的配置，上一篇博客中提到过
- DruidStatViewServletConfiguration：Druid 监控页的配置，默认开启
- DruidWebStatFilterConfiguration：web应用的监控，默认开启
- DruidFilterConfiguration：其他监控，例如SQL监控，防火墙等

‍

DruidStatViewServletConfiguration类的部分源码：可以看到是还是使用了ServletRegistrationBean，并且配置了一些默认值。

也可通过配置文件的方式来绑定属性，其前缀是spring.datasource.druid.stat-view-servlet

@ConditionalOnWebApplication
@ConditionalOnProperty(
    name = {"spring.datasource.druid.stat-view-servlet.enabled"},
    havingValue = "true"
)
public class DruidStatViewServletConfiguration {
    private static final String DEFAULT_ALLOW_IP = "127.0.0.1";

    public DruidStatViewServletConfiguration() {
    }

    @Bean
    public ServletRegistrationBean statViewServletRegistrationBean(DruidStatProperties properties) {
        DruidStatProperties.StatViewServlet config = properties.getStatViewServlet();
        ServletRegistrationBean registrationBean = new ServletRegistrationBean();
        registrationBean.setServlet(new StatViewServlet());
        registrationBean.addUrlMappings(new String[]{config.getUrlPattern() != null ? config.getUrlPattern() : "/druid/*"});
        if (config.getAllow() != null) {
            registrationBean.addInitParameter("allow", config.getAllow());
        } else {
            registrationBean.addInitParameter("allow", "127.0.0.1");
        }

        if (config.getDeny() != null) {
            registrationBean.addInitParameter("deny", config.getDeny());
        }

        if (config.getLoginUsername() != null) {
            registrationBean.addInitParameter("loginUsername", config.getLoginUsername());
        }

        if (config.getLoginPassword() != null) {
            registrationBean.addInitParameter("loginPassword", config.getLoginPassword());
        }

        if (config.getResetEnable() != null) {
            registrationBean.addInitParameter("resetEnable", config.getResetEnable());
        }

        return registrationBean;
    }
}

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42

‍

通过源码可以得出，相关的配置prefix如下：

DruidSpringAopConfiguration：spring.datasource.druid.aop-patterns
DruidStatViewServletConfiguration：spring.datasource.druid.stat-view-servlet
DruidWebStatFilterConfiguration；spring.datasource.druid.web-stat-filter

‍

# 开始配置

修改application.yml：

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/learnjdbc?serverTimezone=UTC
    username: learn
    password: learnpassword
    driver-class-name: com.mysql.cj.jdbc.Driver
    druid:
      filter: stat,wall
      stat-view-servlet:
        enabled: true
        login-username: admin
        login-password: admin
        reset-enable: false
      web-stat-filter:
        enabled: true
        url-pattern: "/*"
        exclusions: "*.js,*.gif,*.jpg,*.bmp,*.png,*.css,*.ico,/druid/*"
      filters: stat,wall #stat监控统计,wall防火墙
      filter: #配置具体的filter
        stat:
          slow-sql-millis: 1000 #慢查询时间
        wall:
          enabled: true
          config:
            drop-table-allow: false #是否允许删除表