最近在springboot2專案中使用了Druid連線池，在此記錄一下，整合過程

首先：引入Maven配置項

<dependency>
    <groupId>com.alibaba</groupId>
    <artifactId>druid-spring-boot-starter</artifactId>
    <version>1.1.9</version>
</dependency>

然後在application.properties核心配置檔案中新增連線配置（本人用的資料庫是mysql）

spring.datasource.druid.url=jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8&useSSL=true
spring.datasource.druid.username=root
spring.datasource.druid.password=root
spring.datasource.druid.initial-size=5
spring.datasource.druid.max-active=20
spring.datasource.druid.min-idle=10
spring.datasource.druid.max-wait=10
spring.datasource.druid.validation-query= select 'x'
spring.datasource.druid.filters=stat,wall
spring.datasource.druid.filter.stat.log-slow-sql=true
spring.datasource.druid.filter.stat.slow-sql-millis=2000

# Druid WebStatFilter配置
spring.datasource.druid.web-stat-filter.enabled=true
spring.datasource.druid.web-stat-filter.url-pattern=/*
spring.datasource.druid.web-stat-filter.exclusions=*.gif,*.png,*.jpg,*.html,*.js,*.css,*.ico,/druid/*

# Druid StatViewServlet配置
spring.datasource.druid.stat-view-servlet.enabled=true
spring.datasource.druid.stat-view-servlet.url-pattern=/druid/*
spring.datasource.druid.stat-view-servlet.reset-enable=true
spring.datasource.druid.stat-view-servlet.login-username=admin
spring.datasource.druid.stat-view-servlet.login-password=
spring.datasource.druid.stat-view-servlet.allow=
spring.datasource.druid.stat-view-servlet.deny=
 

以上就已經整合完畢了，所有的所需資訊都在這個配置檔案中完成

可能有時候覺得application.properties太繁瑣或者不美觀，看起來費勁，我們可以用yml檔案來進行配置，但是需要名稱與原檔名相同，就叫做application.yml，配置資訊如下

spring:
  datasource:
    url: jdbc:mysql://localhost:3306/test?useUnicode=true&characterEncoding=UTF-8&useSSL=true
    username: root
    password: root
    driver-class-name: com.mysql.jdbc.Driver
    type: com.alibaba.druid.pool.DruidDataSource
    initialSize: 5
    minIdle: 5
    maxActive: 20
    # 配置獲取連線等待超時的時間
    maxWait: 60000
    # 配置間隔多久才進行一次檢測，檢測需要關閉的空閒連線，單位是毫秒
    timeBetweenEvictionRunsMillis: 60000
    # 配置一個連線在池中最小生存的時間，單位是毫秒
    minEvictableIdleTimeMillis: 300000
    validationQuery: SELECT 1 FROM DUAL
    testWhileIdle: true
    testOnBorrow: false
    testOnReturn: false
    # 開啟PSCache，並且指定每個連線上PSCache的大小
    poolPreparedStatements: true
    maxPoolPreparedStatementPerConnectionSize: 20
    # 配置監控統計攔截的filters，去掉後監控介面sql無法統計，'wall'用於防火牆，此處是filter修改的地方
    filters: stat,wall,log4j
    #通過connectProperties屬性來開啟mergeSql功能；慢SQL記錄
    connectionProperties: druid.stat.mergeSql=true;druid.stat.slowSqlMillis=5000
    useGlobalDataSourceStat: true
 

在配置檔案中少了一些資訊，這些資訊需要在自定義的配置類中設定，程式碼是

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import com.alibaba.druid.support.http.StatViewServlet;
import com.alibaba.druid.support.http.WebStatFilter;

@Configuration
public class DruidConfiguration {
    private static final Logger logger = LoggerFactory.getLogger(DruidConfiguration.class);

    private static final String DB_PREFIX = "spring.datasource";

    @Bean
    public ServletRegistrationBean druidServlet() {
        logger.info("init Druid Servlet Configuration ");
        ServletRegistrationBean servletRegistrationBean = new ServletRegistrationBean(new StatViewServlet(), "/druid/*");
        // IP白名單
//        servletRegistrationBean.addInitParameter("allow", "*");
        // IP黑名單(共同存在時，deny優先於allow)
//        servletRegistrationBean.addInitParameter("deny", "192.168.0.114");
        //控制檯管理使用者
        servletRegistrationBean.addInitParameter("loginUsername", "admin");
        servletRegistrationBean.addInitParameter("loginPassword", "test");
        //是否能夠重置資料 禁用HTML頁面上的“Reset All”功能
        servletRegistrationBean.addInitParameter("resetEnable", "false");
        return servletRegistrationBean;
    }

    @Bean
    public FilterRegistrationBean filterRegistrationBean() {
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean(new WebStatFilter());
        filterRegistrationBean.addUrlPatterns("/*");
        filterRegistrationBean.addInitParameter("exclusions", "*.js,*.gif,*.jpg,*.png,*.css,*.ico,/druid/*");
        return filterRegistrationBean;
    }
}

yml方式配置Druid連線池已完成，記得加@Configuration的註解，效果與application.properties配置效果相同

出現的問題：一開始我使用的預設.properties方式，並使用了redis做一些熱資料的快取處理，沒什麼問題出現，配置如下

spring.cache.type=redis
spring.cache.redis.cache-null-values=false
spring.cache.redis.time-to-live=3600000
spring.redis.host=localhost
spring.redis.port=6379
spring.redis.database=1
spring.redis.password=000000
spring.redis.timeout=10000

但是當我把配置檔案換為.yml格式檔案時，就會出現連線不到redis密碼錯誤的問題，配置如下

spring:
  cache:
    type: redis
    redis:
      time-to-live: 3600000 
      cache-null-values: false 
  redis:
    port: 6379
    host: localhost
    password: 000000
    timeout: 60000  
    database: 1

最後發現是因為密碼處需要加引號，而在.properties檔案中則不需要........這個坑，現改為

spring:
  cache:
    type: redis
    redis:
      time-to-live: 3600000 
      cache-null-values: false 
  redis:
    port: 6379
    host: localhost
    password: '000000'
    timeout: 60000  
    database: 1

至此所有連線正常

在此發文記錄整合過程，如有不妥請指正