Ben Chuanlong Du's Blog

It is never too late to learn.

BufferedReader in Java IO

Comemnt

  1. The methods BufferedRead.readLine and BufferedRead.lines are very helpful for reading text Files.

public String BufferedRead.readLine

Reads a line of text. A line is considered to be terminated by any one of a line feed ('\n'), a carriage return ('\r'), or a carriage return followed immediately by a linefeed.

public Stream\<String> BufferedRead.lines

Returns a Stream, the elements of which are lines read from this BufferedReader. The Stream is lazily populated, i.e., read only occurs during the terminal stream operation. The reader must not be operated on during the execution of the terminal stream operation. Otherwise, the result of the terminal stream operation is undefined.

Assert in Java

  1. Avoid using assert in Java production code as assertion is not turned on by default. Throw exception instead (since assert is just a syntax sugar of throwing exceptions).

The most important thing to remember about assertions is that they can be disabled, so never assume they'll be executed.

Therefore keep the followings things in mind when using assertions:

Dataframe for JVM

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

Spark DataFrame

Spark DataFrame is a great implementation of distributed DataFrame, if you don't mind having dependency on Spark. It can be used in a non-distributed way of course. Spark DataFrame …

Use Kotlin in a Scala Project

Things on this page are fragmentary and immature notes/thoughts of the author. Please read with your own judgement!

  1. Methods of a Kotlin object can be called in a Scala project by KotlinObject.INSTANCE.methodToCall()

  2. You might need to provide the Kotlin standard library kotlin-stdlib.jar in order to run …