更换Spring Boot 2.0的连接池

前言
前期做gateway demo的时候一直用的都是阿里的Druid，自带监控，但是暂时监控用不上，就想试试HikariCP，所以要将Druid转移至HikariCP连接池
当前Spring Boot版本为：2.1.0.RELEASE

`HikariCP`简介

HikariCP专注于连接池，没有加Druid中的监控功能，轻量级，代码一共只有130kb左右

Github地址: https://github.com/brettwooldridge/HikariCP

Spring Boot 2.0将HikariCP作为默认的连接池，给出了如下解释：

Production database connections can also be auto-configured by using a poolingDataSource. Spring Boot uses the following algorithm for choosing a specific implementation:
We prefer HikariCP for its performance and concurrency. If HikariCP is available, we always choose it.
Otherwise, if the Tomcat pooling DataSource is available, we use it.
If neither HikariCP nor the Tomcat pooling datasource are available and if Commons DBCP2 is available, we use it.

引入依赖

<dependency>
	<groupId>org.springframework.boot</groupId>
	<artifactId>spring-boot-starter-jdbc</artifactId>
</dependency>
<dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>${mysql.version}</version>
      <scope>runtime</scope>
</dependency>

Tips：没有在spring-boot-starter-jdbc的pom文件里发现tomcat-jdbc，可能默认的就已经是HikariCP了吧，所以也不用排除tomcat-jdbc

yaml配置

spring:
  datasource:
  driver-class-name: com.mysql.jdbc.Driver
    url: jdbc:mysql://127.0.0.1:3306/database?useUnicode=true&characterEncoding=utf-8&useSSL=false
    username: root
    password: root
    hikari:
      auto-commit: true
      maximum-pool-size: 60
      minimum-idle: 10
      connection-test-query: SELECT 1
      connection-timeout: 30000
      idle-timeout: 600000
      maxLifetime: 1800000
      read-only: false

这样直接启动就可以了，会看到HikariCP启动成功

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[2018-12-17 11:34:48] [RMI TCP Connection(6)-127.0.0.1] INFO  [com.zaxxer.hikari.HikariDataSource] 110 - HikariPool-1 - Starting...
[2018-12-17 11:34:48] [RMI TCP Connection(6)-127.0.0.1] DEBUG [com.zaxxer.hikari.pool.HikariPool] 545 - HikariPool-1 - Added connection com.mysql.jdbc.JDBC4Connection@3961e5e4
[2018-12-17 11:34:48] [RMI TCP Connection(6)-127.0.0.1] INFO  [com.zaxxer.hikari.HikariDataSource] 123 - HikariPool-1 - Start completed.

配置上的坑

起初配置的时候，是如下这样的

spring:
  datasource:
    hikari:
      jdbc-url: jdbc:mysql://127.0.0.1:3306/database?useUnicode=true&characterEncoding=utf-8&useSSL=false # <1>
      username: root                                 # <2>
      password: root                                 # <3>
      driver-class-name: com.mysql.jdbc.Driver       # <4>
      auto-commit: true
      maximum-pool-size: 60
      minimum-idle: 10
      connection-test-query: SELECT 1
      connection-timeout: 30000
      idle-timeout: 600000
      maxLifetime: 1800000
      read-only: false

当把上面这四项放在spring.datasource.hikari下面的时候，启动会报如下错误：

org.springframework.boot.autoconfigure.jdbc.DataSourceProperties$DataSourceBeanCreationException: Failed to determine a suitable driver class
...
***************************
APPLICATION FAILED TO START
***************************

Description:

Failed to configure a DataSource: 'url' attribute is not specified and no embedded datasource could be configured.

Reason: Failed to determine a suitable driver class


Action:

Consider the following:
	If you want an embedded database (H2, HSQL or Derby), please put it on the classpath.
	If you have database settings to be loaded from a particular profile you may need to activate it (no profiles are currently active).

“无法确定合适的驱动类”，配置DataSource下的'url'参数失败，像阿里自己封装的druid-starter，所有都配置spring.datasource.druid在即可，所以出现上面问题的解决办法就是使用yaml配置这里的配置就可以了。

BTW，好像没在

还有一个小问题就是IDEA针对spring.datasource.driver-class-name这一项配置居然不识别，虽然报错，但是不影响使用

IDEA当前版本：IntelliJ IDEA 2018.3.1 (Ultimate Edition)

结束！🔚

HikariCP简介

引入依赖

yaml配置

配置上的坑

`HikariCP`简介