Book Image

Java 9 Concurrency Cookbook, Second Edition - Second Edition

By : Javier Fernández González
Book Image

Java 9 Concurrency Cookbook, Second Edition - Second Edition

By: Javier Fernández González

Overview of this book

Writing concurrent and parallel programming applications is an integral skill for any Java programmer. Java 9 comes with a host of fantastic features, including significant performance improvements and new APIs. This book will take you through all the new APIs, showing you how to build parallel and multi-threaded applications. The book covers all the elements of the Java Concurrency API, with essential recipes that will help you take advantage of the exciting new capabilities. You will learn how to use parallel and reactive streams to process massive data sets. Next, you will move on to create streams and use all their intermediate and terminal operations to process big collections of data in a parallel and functional way. Further, you’ll discover a whole range of recipes for almost everything, such as thread management, synchronization, executors, parallel and reactive streams, and many more. At the end of the book, you will learn how to obtain information about the status of some of the most useful components of the Java Concurrency API and how to test concurrent applications using different tools.
Table of Contents (12 chapters)

Writing effective log messages

A log system is a mechanism that allows you to write information to one or more destinations. A Logger has the following components:

  • One or more handlers: A handler will determine the destination and format of the log messages. You can write log messages in the console, a file, or a database.
  • A name: Usually, the name of a Logger used in a class is based on the class name and its package name.
  • A level: Log messages have different levels that indicate their importance. A Logger also has a level to decide what messages it is going to write. It only writes messages that are as important as, or more important, than its level.

You should use the log system because of the following two main reasons:

  • Write as much information as you can when an exception is caught. This will help you localize the error and resolve it.
  • Write information about the classes and methods that the program is...