In this book, you will find a number of styles of text that distinguish between different kinds of information. Here are some examples of these styles, and an explanation of their meaning.

Code words in text are shown as follows:"The /lib folder holds the scala-library.jar file."

A block of code is set as follows:

import java.util.List;
public final class MapData {
    private final List<WordCount> dataList;
    public List<WordCount> getDataList() {
        return dataList;
    public MapData(List<WordCount> dataList) {
        this.dataList = dataList;

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

package; import ...

Get Akka Essentials now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.