2、使用Druid数据源

2.1 druid官方github地址

https://github.com/alibaba/druid

整合第三方技术的两种方式

• 自定义
• 找starte

2.2 自定义方式

2.2.1 创建数据源

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
            <version>1.1.17</version>
        </dependency>
<bean id="dataSource" class="com.alibaba.druid.pool.DruidDataSource"
        destroy-method="close">
        <property name="url" value="${jdbc.url}" />
        <property name="username" value="${jdbc.username}" />
        <property name="password" value="${jdbc.password}" />
        <property name="maxActive" value="20" />
        <property name="initialSize" value="1" />
        <property name="maxWait" value="60000" />
        <property name="minIdle" value="1" />
        <property name="timeBetweenEvictionRunsMillis" value="60000" />
        <property name="minEvictableIdleTimeMillis" value="300000" />
        <property name="testWhileIdle" value="true" />
        <property name="testOnBorrow" value="false" />
        <property name="testOnReturn" value="false" />
        <property name="poolPreparedStatements" value="true" />
        <property name="maxOpenPreparedStatements" value="20" />

 @ConfigurationProperties("spring.datasource")
    @Bean
    public DataSource dataSource() throws SQLException {
        DruidDataSource druidDataSource = new DruidDataSource();
//        druidDataSource.setFilters("stat,wall");
//          druidDataSource.setUsername();
//          druidDataSource.setUrl();
//          druidDataSource.setPassword();
        return druidDataSource;
    }

2.2.2 StatViewServlet（监控页功能）

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>
  

  @Bean
    public ServletRegistrationBean statViewServlet(){
        StatViewServlet statViewServlet = new StatViewServlet();
        ServletRegistrationBean<StatViewServlet> registrationBean = new ServletRegistrationBean<>(statViewServlet, "/druid/*");
        //设置监控页的登录用户名和密码
        registrationBean.addInitParameter("loginUsername", "admin");
        registrationBean.addInitParameter("loginPassword", "admin");
        return registrationBean;
    }
  

  2.2.3 StatFilter

  用于统计监控信息；如SQL监控、URI监控 ```xml 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：

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**
```xml
<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

2.3 使用官方starter方式

2.3.1 引入druid-starter

        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid-spring-boot-starter</artifactId>
            <version>1.1.17</version>
        </dependency>

2.3.2 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";

2.3.3 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    #禁止删除功能

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