SPI ABC
SPI 代表Service Provider Interfaces, 是一种服务提供发现的机制。JDK中为其提供了ServiceLoader用来加载接口对应的实现。
grep 总结
常见用法
示例文本：
“Night gathers, and now my watch begins. It shall not end
until my death. I shall take no wife, hold no lands, father no
children. I shall wear no crowns and win no glory. I shall live
and die at my post. I am the sword in the darkness. I am the
watcher on the walls. I am the shield that guards the realms of
men. I pledge my life and honor to the Night’s Watch, for this
night and all the nights to come.”
