【JDK8】Map 便利的預設方法

 https://openhome.cc/Gossip/CodeData/JDK8/Map.html

 

computeIfAbsent和computeIfPresent使用範例
https://stackoverflow.com/questions/59493461/can-i-use-concurrenthashmap-with-integer-for-thread-safe-counters

HikariCP Example

Java 6
https://github.com/imrexhuang/HikariCPClientExample/tree/master/ForJava6

Java 8+
https://github.com/imrexhuang/HikariCPClientExample/tree/master/ForJava8%2B

HikariCP
https://github.com/brettwooldridge/HikariCP#configuration-knobs-baby

HikariCP Maven:
https://search.maven.org/search?q=com.zaxxer.hikaricp

作者:Brett Wooldridge
https://github.com/brettwooldridge

作者為何要開發HikariCP的專訪
https://dzone.com/articles/jooq-tuesdays-what-it-takes-to-write-the-fastest-java-connection-pool

【追光者系列】HikariCP默认配置

利用SQL Server的sp_who指令查看
沒有設定setMinimumIdle和setMaximumPoolSize時，的確預設是建立10個Connection

超過預設10個Connection會出現以下錯誤訊息，無法再用HikariDataSource去getConnection導致timeout：

java.sql.SQLTimeoutException: Timeout after 30004ms of waiting for a connection.
    at com.zaxxer.hikari.pool.BaseHikariPool.getConnection(BaseHikariPool.java:233)
    at com.zaxxer.hikari.pool.BaseHikariPool.getConnection(BaseHikariPool.java:183)
    at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:93)
    at HikariCPDataSource.getConnection(HikariCPDataSource.java:33)
    at SQLServerPOC.main(SQLServerPOC.java:25)