Beginner Java Programmers

I have been programming in Java for 7 years now. But at work, you often have to train a new generation. In this regard, I decided to make some cheat sheet, which, I hope, will be useful for habrchan. If someone can help supplement something from the information in this article, then write! So:

Key Resources for Elementary Learning

• www.javable.com is a site with articles and a tutorial on Java. Everything is mostly in Russian.
• www.exampledepot.com is a very useful resource that contains brief examples of using classes for specific packages.
• java.sun.com - you can’t do without the source. For any Java programmer, the JavaDoc must be the ultimate truth. Here you can also find a series of tutorials on all possible topics.

Basic Java packages

Below is a list of Java packages in which the programmer should be free to navigate. It is recommended to get acquainted with them both in JavaDocs and with the help of www.exampledepot.com . All packages are arranged in the recommended order for study. So:

1. java.lang is the foundation of the basics. Each class in this package needs special attention.
2. java.io - no program can do without I / O operations.
3. java.util - the package basically contains everything you need to work with collections: Collection, Enumeration, Set, List, Map, etc. etc.
4. java.net - contains the main classes for working with the network.
5. java.text - everything you need to format text
6. java.lang.reflect - Java would not be Java if not for Reflection. Reflection erases the line between data and code.
7. javax.sql - everything you need to work with databases
8. javax.xml. * , org.w3c.dom. * , org.xml.sax. * - without these packages working with XML is simply unthinkable

Resources to broaden your horizons

• onjava.com - sooner or later all the Java world news gets here
• www.javaspecialists.eu - the resource is useful for both beginners and advanced programmers, as it contains many articles about the intricacies of working with Java.
• www.theserverside.com - it is recommended to subscribe to RSS, as very interesting things in Java often skip.

Java Libraries Everybody Should Know

Java does not end with knowledge only about the capabilities of the JSDK. To feel comfortable, you need to know another dozen two third-party libraries used by Java programmers everywhere. So, let's start with the main ones:

• Commons Lang - what they "forgot" to include in the JDK
• Commons Math is a great add-on for java.math
• Commons Logging - Logging must be competent. For System.out.println, for beginning logs, beginning programmers should cut their hands off after a week of training.
• Commons Net is a logical continuation for the java.net package. Many classes for working with basic network protocols.
• Commons VFS is a great library for abstracting from the way a file is stored. Allows a fairly generalized access to files via FTP, SFTP, WEBDAV, (G) ZIP, etc.
• Commons IO - working with I / O often turns out to be very dreary, but with this library everything becomes a little more fun.
• HttpClient - library for working with http resources.
• JUnit - any code should be accompanied by testing. This test automation is intended for test automation.

That's all for now. If you are interested in such Java cheat sheets, then I can also lay out my collection of “simple” Java tasks that are oriented towards quickly mastering basic Java packages.