技術標籤：hikaridatasource配置及使用

Hikari 目前是 SpringBoot 預設的連線池。

區別於 c3p0 直接通過連線池物件獲取各項狀態指標，Hikari需要通過JMX來獲取。

示例程式碼如下， SpringBoot 整合，定時採集 Hikari 連線池 連線狀態 。

@Component
@Controller
@SpringBootApplication(exclude = DataSourceAutoConfiguration.class)
@EnableScheduling
public class HikariTest {

	private static HikariPoolMXBean poolProxy;
	private static final Logger log = LoggerFactory.getLogger(HikariTest.class);

	public static void main(String[] args) throws SQLException, MalformedObjectNameException, InterruptedException {
	
		SpringApplication.run(HikariTest.class, args);
		HikariDataSource hikaridatasource = new HikariDataSource();
		hikaridatasource.setJdbcUrl("jdbc:mysql://localhost:3306?serverTimezone=GMT");
		hikaridatasource.setUsername("root");
		hikaridatasource.setPassword("root");
		hikaridatasource.setDriverClassName("com.mysql.cj.jdbc.Driver");
		hikaridatasource.setRegisterMbeans(true);
		hikaridatasource.setPoolName("HikariConnectionPool");
		
		MBeanServer mBeanServer = ManagementFactory.getPlatformMBeanServer();
		ObjectName poolName = new ObjectName("com.zaxxer.hikari:type=Pool (" + hikaridatasource.getPoolName() + ")");
		poolProxy = JMX.newMXBeanProxy(mBeanServer, poolName, HikariPoolMXBean.class);
		
		Connection conn = hikaridatasource.getConnection();
		Statement sm = conn.createStatement();
		ResultSet rs = null;
		for (int i = 0; i < 999999999; i++) {
			rs = sm.executeQuery("select name from test.t1");
		}
		rs.close();
		sm.close();
		conn.close();
		hikaridatasource.close();
	}

	@Scheduled(fixedRate = 1000)
	public void HikariMonitor() {
		if(poolProxy == null) {
			log.info("Hikari not initialized,please wait...");
		}else {
			log.info("HikariPoolState = "
					+ "Active=[" + String.valueOf(poolProxy.getActiveConnections() + "] "
					+ "Idle=[" + String.valueOf(poolProxy.getIdleConnections() + "] "
					+ "Wait=["+poolProxy.getThreadsAwaitingConnection()+"] "
					+ "Total=["+poolProxy.getTotalConnections()+"]")));
		}
		
	}
 

在github上，有幾位小夥伴都提到了一個issue（我也遇到了），是這裡

ObjectName poolName = new ObjectName("com.zaxxer.hikari:type=Pool (" + hikaridatasource.getPoolName() + ")");

可能會 throw exception

22:06:23.231 [main] DEBUG com.zaxxer.hikari.HikariConfig - Driver class com.mysql.cj.jdbc.Driver found in Thread context class loader 
 
[email protected]
Exception in thread "main" java.lang.reflect.UndeclaredThrowableException
	at com.sun.proxy.$Proxy2.getIdleConnections(Unknown Source)
	at com.zte.hikariTest.HikariTest.main(HikariTest.java:32)
Caused by: javax.management.InstanceNotFoundException: com.zaxxer.hikari:type=Pool (foo)
	at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.getMBean(Unknown Source)
	at com.sun.jmx.interceptor.DefaultMBeanServerInterceptor.getAttribute(Unknown Source)
	at com.sun.jmx.mbeanserver.JmxMBeanServer.getAttribute(Unknown Source)
	at com.sun.jmx.mbeanserver.MXBeanProxy$GetHandler.invoke(Unknown Source)
	at com.sun.jmx.mbeanserver.MXBeanProxy.invoke(Unknown Source)
	at javax.management.MBeanServerInvocationHandler.invoke(Unknown Source)
	... 2 more
 

Hikari設定引數同樣支援setHikariConfig和配置檔案兩種配置方式，請選擇其中一種進行配置，而不是二者一起使用。並且請配置屬性如下，否則JMX無法生效。

hikaridatasource.setRegisterMbeans(true);

效果如下圖

2020-07-09 02:05:03.725 INFO com.zte.hikariTest.HikariTest.67 -Hikari connection pool is not already...please wait...
2020-07-09 02:05:03.726 INFO o.a.c.http11.Http11NioProtocol.173 -Starting ProtocolHandler ["http-nio-8080"]
2020-07-09 02:05:03.760 INFO o.s.b.w.e.t.TomcatWebServer.204 -Tomcat started on port(s): 8080 (http) with context path ''
2020-07-09 02:05:03.763 INFO com.zte.hikariTest.HikariTest.59 -Started HikariTest in 3.487 seconds (JVM running for 3.98)
2020-07-09 02:05:03.775 INFO c.z.hikari.HikariDataSource.110 -HikariConnectionPool - Starting...
2020-07-09 02:05:04.439 INFO c.z.hikari.HikariDataSource.123 -HikariConnectionPool - Start completed.
2020-07-09 02:05:04.738 INFO com.zte.hikariTest.HikariTest.69 -HikariPoolState = Active=[1] Idle=[9] Wait=[0] Total=[10]
2020-07-09 02:05:05.740 INFO com.zte.hikariTest.HikariTest.69 -HikariPoolState = Active=[1] Idle=[9] Wait=[0] Total=[10]
2020-07-09 02:05:06.732 INFO com.zte.hikariTest.HikariTest.69 -HikariPoolState = Active=[1] Idle=[9] Wait=[0] Total=[10]
2020-07-09 02:05:07.738 INFO com.zte.hikariTest.HikariTest.69 -HikariPoolState = Active=[1] Idle=[9] Wait=[0] Total=[10]