Java

Basics

• Java Abstract Class vs Interface Pros and Con's
• Java Finalize Method: When and How to Implement It?
• How to Silently Close Resources in Java?

Class, Resource & Service Loading

• ServiceLoader Example
• Understanding Absolute and Relative Path with getResourceAsStream()

Core

• Java Number Formatting Summary
• Java: How to Iterate Through a Map?
• Java Generics: Part I  Part II   Part III   Part IV 
• Java: instanceof, isAssignableFrom() or isInstance()?
• Is finally always called in a try catch Java statement? 
• About using system.exit() in try catch finally Java statements
• Generate A Random Number Within a Range in Java
• About Java TimeZone and Calendar Caveats

Email

• Sending Plain Or HTML Emails
• Adding An Image Attachment To An Email

Encoding, Conversion & Digest/Hash

• Encode & Decode URL Parameters (Query Strings) in Java
• How to Convert an InputStream into a Byte Array in Java?
• How to Encode and Decode Data to Base64 in Java? 
• How to Convert a Byte Array Into an Hexadecimal String?
• How to Digest (or Hash) data with MD5, SHA1, SHA256 in Java?

FreeMarker

• FreeMarker Reminders

Internationalization

• Introduction To Java Internationalization

Javascript

• Calling Javascript From Java

JAXB

• JAXB to XML Marshalling and Unmarshalling
• JAXB to JSON Marshalling and Unmarshalling
• JAXB Annotations Tutorial

JPA

• See the JPA Tutorial with Examples using Hibernate in Standalone

Logging

• Understanding Logging Frameworks In Java

Performace

• Java Performance Tips & Tricks

Security & Cryptography

• How to Generate a Public Private Key Pair in Java?
• AES 128/192/256 Private Key Generation in Java
• AES 256 Symmetric Encryption with BouncyCastle

Sitemesh

• Quick Introduction To Sitemesh Concepts

Testing

• Java TestNG Example

Tomcat

• Installing and Running Tomcat 7 on Windows 7
• About user login & password of NetBeans' Tomcat installation
• How to deploy a .war to Tomcat 7 during a maven build process?
• What is the context.xml file in a Maven Web Application?

Web Application

• What is web.xml (Deployment Descriptor) in Java?
• What is the context.xml file in a Web Application?
• Introduction to J2EE Concepts 
• What is JNDI, SPI, CCI, LDAP and JCA?

XML & JSON

• Parse & Create XML Documents in Java 
• Parse & Create JSON Documents in Java