11 2016 档案

摘要:1. 基本原理: 通过hadoop fs -ls *命令获取相关文件或目录的修改时间,然后与设定的过期时间进行比较,之后执行删除操作即可 2. 相关代码: 参考:Hadoop运维-删除目录下过期的数据 阅读全文
posted @ 2016-11-29 17:32 mengrennwpu 阅读(7844) 评论(0) 推荐(2) 编辑
摘要:Scala's object-oriented collections support mutable and immutable type hierarchies. Also support functional higher-order operations such as map, filte 阅读全文
posted @ 2016-11-28 22:31 mengrennwpu 阅读(349) 评论(0) 推荐(0) 编辑
摘要:The basic functional cornerstones of Scala: immutable data types, passing of functions as parameters and pattern matching. 1. Basic Pattern Matching I 阅读全文
posted @ 2016-11-27 17:20 mengrennwpu 阅读(313) 评论(0) 推荐(0) 编辑
摘要:1. Functional programming treats computation as the evaluation of mathematical and avoids state and mutable data. Scala encourages an expression-orien 阅读全文
posted @ 2016-11-27 15:02 mengrennwpu 阅读(314) 评论(0) 推荐(0) 编辑
摘要:1. The three principles of OOP are encapsulation(封装性), inheritance(继承性) and polymorphism(多态性). example: A subtype is guaranteed to have all the member 阅读全文
posted @ 2016-11-26 12:43 mengrennwpu 阅读(252) 评论(0) 推荐(0) 编辑
摘要:1. Variables (1) Three ways to define variables: 1) val refers to define an immutable variable; 2) var refers to define a mutable variable. 3) lazy va 阅读全文
posted @ 2016-11-25 15:27 mengrennwpu 阅读(260) 评论(0) 推荐(0) 编辑
摘要:1. Scala is a contraction of "scalable" and "language". It's a fusion of objected-oritended and functional programming. 2. Compare Book class between 阅读全文
posted @ 2016-11-25 14:32 mengrennwpu 阅读(215) 评论(0) 推荐(0) 编辑