前言
springboot让java开发更加美好，更加简洁，更加简单。spring boot 2.x中使用hikaricp作为默认的数据连接池。 hikaricp使用javassist字节码操作库来实现动态代理，优化并精简了字节码，同时内部使用 com.zaxxer.hikari.util.fastlist 代替arraylist、使用了更好的并发集合类 com.zaxxer.hikari.util.concurrentbag ，“号称”是目前最快的数据库连接池。
下面话不多说了，来一起看看详细的介绍吧
基本使用
在spring boot 2.x中使用hikaricp十分简单，只需引入依赖 implementation 'org.springframework.boot:spring-boot-starter-jdbc' ：
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pluginmanagement {
repositories {
gradlepluginportal()
}
}
rootproject.name = 'datasource-config'
plugins {
id 'org.springframework.boot' version '2.1.3.release'
id 'java'
}
apply plugin: 'io.spring.dependency-management'
group = 'spring-boot-guides'
version = '0.0.1-snapshot'
sourcecompatibility = '1.8'
repositories {
mavencentral()
}
dependencies {
implementation 'org.springframework.boot:spring-boot-starter-jdbc'
runtimeonly 'com.h2database:h2'
testimplementation 'org.springframework.boot:spring-boot-starter-test'
}
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配置文件如下：
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spring:
datasource:
url: jdbc:h2:mem:demodb
username: sa
password:
hikari: # https://github.com/brettwooldridge/hikaricp (uses milliseconds for all time values)
maximumpoolsize: 10
minimumidle: 2
idletimeout: 600000
connectiontimeout: 30000
maxlifetime: 1800000
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关于连接池的具体配置参数详见 hikaricp 。
示例代码如下：
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package springbootguides.datasourceconfig;
import org.springframework.beans.factory.annotation.autowired;
import org.springframework.boot.commandlinerunner;
import org.springframework.boot.springapplication;
import org.springframework.boot.autoconfigure.springbootapplication;
import javax.sql.datasource;
import java.sql.connection;
@springbootapplication
public class datasourceconfigapplication implements commandlinerunner {
@autowired
private datasource datasource;
@override
public void run(string... args) throws exception {
try(connection conn = datasource.getconnection()) {
system.out.println(conn);
}
}
public static void main(string[] args) {
springapplication.run(datasourceconfigapplication.class, args);
}
}
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实现原理
spring boot使用如下方式整合hikaricp：入口是 org.springframework.boot.autoconfigure.jdbc.datasourceautoconfiguration ，通过 org.springframework.boot.autoconfigure.jdbc.datasourceconfiguration.hikari 中的 @bean 方式创建 com.zaxxer.hikari.hikaridatasource ：
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/**
* hikari datasource configuration.
*/
@conditionalonclass(hikaridatasource.class)
@conditionalonmissingbean(datasource.class)
@conditionalonproperty(name = "spring.datasource.type", havingvalue = "com.zaxxer.hikari.hikaridatasource", matchifmissing = true)
static class hikari {
@bean
@configurationproperties(prefix = "spring.datasource.hikari")
public hikaridatasource datasource(datasourceproperties properties) {
hikaridatasource datasource = createdatasource(properties,
hikaridatasource.class);
if (stringutils.hastext(properties.getname())) {
datasource.setpoolname(properties.getname());
}
return datasource;
}
}
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@configurationproperties(prefix = "spring.datasource.hikari") 会自动把 spring.datasource.hikari.* 相关的连接池配置信息注入到创建的hikaridatasource实例中。
hikaricp的监控和遥测
因为在我们的微服务体系中使用的监控系统是prometheus，这里以prometheus为例。
注意spring boot 2.0对spring boot 1.x的metrics进行了重构，不再向后兼容，主要是在spring-boot-acutator中使用了micrometer，支持了更多的监控系统：atlas、datadog、ganglia、graphite、influx、jmx、newrelic、prometheus、signalfx、statsd、wavefront。spring boot 2.0的metrics对比spring boot 1.x除了引入micrometer外，更大的体现是支持了tag，这也说明prometheus、influx等支持tag的时序监控数据模型的监控系统已经成为主流。
在前面示例中的build.gradle中加入如下依赖：
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implementation 'org.springframework.boot:spring-boot-starter-web'
implementation 'org.springframework.boot:spring-boot-starter-actuator'
implementation 'io.micrometer:micrometer-registry-prometheus'
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配置文件applycation.yaml中加入对actuator的配置：
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management:
endpoints:
web:
exposure:
include: "health,info,prometheus"
server:
port: 8079
servlet:
context-path: /
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注意这里引入了web和actuator依赖，通过配置 management.server.port 指定actuator的web端点为8089端口，通过 management.endpoints.include 对外开放 /actuator/prometheus ，在引入 io.micrometer:micrometer-registry-prometheus 依赖之后，端点 /actuator/prometheus 当即生效。
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curl http://localhost:8079/actuator/prometheus | grep hikari
# type hikaricp_connections_acquire_seconds summary
hikaricp_connections_acquire_seconds_count{pool="hikaripool-1",} 3.0
hikaricp_connections_acquire_seconds_sum{pool="hikaripool-1",} 0.001230082
# help hikaricp_connections_acquire_seconds_max connection acquire time
# type hikaricp_connections_acquire_seconds_max gauge
hikaricp_connections_acquire_seconds_max{pool="hikaripool-1",} 0.0
# help hikaricp_connections_min min connections
# type hikaricp_connections_min gauge
hikaricp_connections_min{pool="hikaripool-1",} 2.0
# type hikaricp_connections_timeout_total counter
hikaricp_connections_timeout_total{pool="hikaripool-1",} 0.0
# help hikaricp_connections_pending pending threads
# type hikaricp_connections_pending gauge
hikaricp_connections_pending{pool="hikaripool-1",} 0.0
# help hikaricp_connections_usage_seconds connection usage time
# type hikaricp_connections_usage_seconds summary
hikaricp_connections_usage_seconds_count{pool="hikaripool-1",} 3.0
hikaricp_connections_usage_seconds_sum{pool="hikaripool-1",} 0.06
# help hikaricp_connections_usage_seconds_max connection usage time
# type hikaricp_connections_usage_seconds_max gauge
hikaricp_connections_usage_seconds_max{pool="hikaripool-1",} 0.0
# help hikaricp_connections_max max connections
# type hikaricp_connections_max gauge
hikaricp_connections_max{pool="hikaripool-1",} 10.0
# help hikaricp_connections total connections
# type hikaricp_connections gauge
hikaricp_connections{pool="hikaripool-1",} 2.0
# help hikaricp_connections_creation_seconds_max connection creation time
# type hikaricp_connections_creation_seconds_max gauge
hikaricp_connections_creation_seconds_max{pool="hikaripool-1",} 0.0
# help hikaricp_connections_creation_seconds connection creation time
# type hikaricp_connections_creation_seconds summary
hikaricp_connections_creation_seconds_count{pool="hikaripool-1",} 1.0
hikaricp_connections_creation_seconds_sum{pool="hikaripool-1",} 0.001
# help hikaricp_connections_idle idle connections
# type hikaricp_connections_idle gauge
hikaricp_connections_idle{pool="hikaripool-1",} 2.0
# help hikaricp_connections_active active connections
# type hikaricp_connections_active gauge
hikaricp_connections_active{pool="hikaripool-1",} 0.0
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参考
• hikaricp
总结
以上就是这篇文章的全部内容了，希望本文的内容对大家的学习或者工作具有一定的参考学习价值，谢谢大家对服务器之家的支持。
原文链接：http://blog.frognew.com/2019/02/spring-boot-guides-hikari.html