Akka (2) — Actor: life cycle & create an actor & send message & stop actors & kill an actor

Akka is a messaging system based on actor module(message should be immutable, this is to avoid the shared mutable state trap). So this post, we focus on talking about Actor…

Slick (3) — connection pool

Before talking into detailed knowledge about connection pool in Slick, we need to figure out two things: One is about Slick. Slick does not provide a connection pool implementation of its own. The other thing is about JDBC, which not provides asynchronous database driver for JVM…

Akka (4) — ActorSystem

Akka is a toolkit which provides by actor model, featured by concurrency, fault-tolerance and scalability. So this post talks about ActorSystem.

• An ActorSystem is heavyweight structure that will allocated 1…N thread, so create one per logical application.

Akka (3) — Dispatchers

• Concept
• Every ActorSystem will have a default dispatcher that will be in case nothing else is configured for an actor. The default dispatcher can be configured, and is by default a Dispatcher with a specified default executor.
  An Akka MessageDispatcher is what…

Text Extraction From URL by Scala

In this post, we talk about how to extract text from URL. Please note, we not involve special pages (e.g. Facebook posts, Facebook comments, etc) into this talk. But in another post, I will write a solution for Facebook posts extracting.

Scala (20) — Execution Context

Execution Context:

• An ExecutionContext is similar to an Executor: it is free to execute computations in a new thread, in a pooled thread or in the current thread (although executing the computation in the current thread is discouraged)

Scala (19) — Futures

Futures

• They hold the promise for the result of a computation that is not yet complete. They are a simple container- a placeholder. A computation could fail of course, and this must also be encoded. a Future can be in exactly one of 3 states:

Slick (1) — fix more than 22 columns case

Slick is a modern database query and access library for Scala. So it is quite clear to understand Slick’s purpose is to query database. This post is to explain how to fix the access to a table which has more than 22 columns. First, we give known solution…

Play Framework (9) — HTTP Routing & Results & Action & Body Parsers & HTTP server

HTTP Routing:

• The router is the component in charge of translating each incoming HTTP request to an Action. Each route consists of an HTTP method, and URI…