JAVA concurrent java.util.concurrent is package that provides classes/interfaces that related to concurrent execution Important interfaces/classes Respresent the object that can execute the given ...

What Pandas is Pandas is python library for data analysis. Its name came from “panel data”. We can import data from various source into datastructure so called “DataFrame” and do computation/manipu...

Scala Scala is a language that base on JVM Scala is functional language that inherit from Haskell Functions are first class citicen in Scala val, var, def, lazy val val : val is immutab...

Scala Generic Scala type system support generic. Generic classes are classes that take a type(s) as parameter. For example, List[T], Seq[T], Option[T]. The following code will be used as an exampl...

Analysis of Algorithms The naive way to compare the performanace of 2 algorithms is to run both of them by given the same input and measure time or space that they use. This is quite not effective ...

JAVA IO java.io is package that provides system input and output through data streams. Read write file, socket. Important interface/abstract Closable: to indicate that this class hold resource tha...

Linear Data structure Array Fix size data structure. [A][B][C][D] Linked list Linear data structure similar to Array. Instead of allocates data size by size, let each node contains data and a ...

Reactive Streams Provides standard for asynchronous stream, non-blocking applications. Use “Pull” model (Subscriber ask for data) instead of “Push” model (Publisher publish data) There are 4...

RESTful APIs (Just a HTTP) It’s actually “software architectural style” that introduce by Roy Fielding not a protocal Simple CRUD API that build on top of HTTP protocal that try to match CRUD ...

Background Authenticaion : is the process that to confirm that users are who they claim they are. Think of computer user/password that allow the users who knows user/password to get in. Author...