Beauty and strangeness of generics

Recently, I was preparing for my Oracle Certified Professional, Java SE 7 Programmer exam and I happened to encounter some rather strange-looking constructions in the realm of generics in Java. Nevertheless, I have also seen some clever and elegant pieces of code. I found these examples worth sharing not only because they can make your design choices easier and resulting code more robust and reusable, but also because some of them are quite tricky when you are not used to generics. I decided to break this post into four chapters that pretty much map my experience with generics during my studies and work experience.

Working with files and directories in NIO.2

In previous articles I discussed creation (Creating files and directories) and selection (Listing and filtering directory contents) of files and directories. The last logical step to take is to explore what can we do with them and how. This is a part of the library that was redesigned in a big way. Updates in this area include guarantee of atomicity of certain operations, API improvements, performance optimization as well as introduction of proper exception hierarchy that replaced boolean returning methods from prior versions of IO library.

Listing and filtering directory contents in NIO.2

There hasn’t been much happening in the area of listing directory contents until the release of Java 7. But since NIO.2 introduced a new way to do this it might be worth it to cover this area. One of big pluses of NIO.2 is the ability to use listing and filtering at once in one method call. This provides an elegant solution to most of listing/filtering needs related to work with a file system.

Creating files and directories in NIO.2

Great number of applications nowadays create files or directories for very wide range of purposes. Whether it is to generate a report, export piece of configuration or simply to store some data it is important to be able to handle these tasks. Creating files and directories is one of the most heavily used functionality while working with a file system. This part of library underwent quite a modernization. Updates in this area include guarantee of atomicity of certain operations, creation of files and directories with preset file attributes, performance optimization as well as introduction of exception hierarchy that replaced boolean returning methods from prior versions of IO library.