c3p0

https://blog.youkuaiyun.com/Peng_Hong_fu/article/details/52742366

https://blog.youkuaiyun.com/u013087513/article/details/55210238

https://www.cnblogs.com/ygj0930/p/6405861.html

https://blog.youkuaiyun.com/u014402683/article/details/74935581

https://blog.youkuaiyun.com/wqc19920906/article/details/72825793

https://blog.youkuaiyun.com/qq_18895659/article/details/51813875