Monday, 5 March 2012

Java 7 New Features Cookbook Review

Java 7 is the latest major release of the Java Language from Oracle. This release contains a number of language enhancements and new APIs, including better exception handling, new threading mechanisms and additions to the core libraries.

Packt Publishing requested that I review one of their titles about Java 7: Java 7 New Features Cookbook by Richard M. Reese and Jennifer L. Reese, available to buy from Packt's website.

Java 7 New Features Cookbook is an OK, but sometimes inconsistent book. I found parts of it very informative and other parts frustrating, with errors here and there in the example code – overall I'd give it an average score. 

The information in the book is very densely packed, but often repetitive and sometimes very slow reading. The information is presented in recipes - how-to examples focusing on a specific Java 7 feature, put together to form a cookbook.

Each recipe is presented in a formulaic way, with information under the sub-headings: 'Getting ready', 'How to do it...', 'How it works...' and 'There's more'. The code examples sufficiently cover the new feature they are trying to demonstrate, and are quite self contained, so you don't need to read the whole chapter to quickly get going with a new Java 7 feature. The 'There's more' sections expand on the basics, fleshing out the examples and include some good tips.

The book covers the full range of Java 7 new features, without going over old ground with respect to previous versions of Java. The book is definitely aimed at developers who are familiar with writing programs in Java 5 and beyond, and not for developers new to Java and OOP. A previous knowledge of Java file I/O, concurrency and a bit of SQL is required to get the most from this book.

This book was difficult to read from cover to cover, and I wouldn't suggest reading it that way. I would recommend consulting its relevant recipes before implementing new code.

A Java 7 JDK installation and an editor are requirements to reproduce the examples in the book. NetBeans 7 is stated as the IDE used to develop the code, but Eclipse or any other IDE or text editor could be used.

A note on the code examples in the book: the immediate thing you notice about the code examples is that they are badly formatted. This coupled with occasional errors in the code and new language syntax, such as try-with-resources, makes for frustrating debugging. The poor code layout is a problem throughout the book and spoilt my enjoyment of it slightly.

Chapter 1 covers new language features from Project Coin. These are small language enhancements designed to make code more readable, more useful and reduce verbosity. The useful new features to take away from this chapter are the new try-with-resources exception handling code, the use of the new AutoClosable interface, catching multiple exception types and using the diamond operator. 

This chapter is a good introduction to Java 7 and I think most developers will want to get to grips with all the recipes.

Chapter 2 introduces the new Paths and FileSystem objects, which are used extensively in subsequent chapters. The new classes provide utility methods to simplify the manipulation and comparison of file paths, helping to reducing some of the bespoke code you may have had to write in previous Java versions. The most important feature introduced in this chapter is the managing of symbolic links, but you will need to be running an operating system that supports them.

Chapter 3 deals with file and directory attributes. The first recipe demonstrates a useful new method for determining a files MIME type, something which has required 3rd party libraries in the past. The chapter goes on to give examples of managing file attributes, including support for DOS and POSIX file systems, very useful for managing Linux file permissions, which wasn't directly possible before.

Chapter 4 builds on the previous chapters and uses the new Files object to create, copy, move and delete files and directories with much more control, and much less code than was previously possible. Useful new features presented are temporary file and directory management and creating symbolic and hard links.

Chapter 5 has loads of useful information for interacting with file systems. Recipes include: accessing root file store information, processing directory contents with DirectoryStream, file filtering, globbing patterns, file event monitoring and more! Lastly in this chapter, the ZIP filesystem provider recipe demonstrates how to treat a ZIP or JAR file as though they were file systems.

Java is often criticised for the amount of code needed to perform simple file reading and writing operations. Chapter 6 shows how simple these operations can now be with Java 7, including new APIs for working with buffered I/O.  The new SeekableByteChannel class for random access I/O, and the new AsynchronousServerSocketChannel class for building client-server applications are recipes also worth visiting.

Thankfully, after half the book, this is the last chapter that deals with paths, files, files systems, file permissions and file I/O.

Chapter 7 showcases additions to swing which can improve the look of your GUI interfaces. Some of the cool looking new features include window opacity, varying gradient window translucency, and custom window shapes. Less exciting, but definitely useful, border type and print dialog box control recipes are also worth taking a look at in this chapter.

Chapter 9 contains a mix of new features, but has some really useful recipes. Firstly the RowSetFactory example shows how to really reduce the amount of JDBC boiler plate code needed to connect to a SQL database, execute queries and iterate over the returned data.

The next recipe demonstrates further database enhancements for reading database schema and pseudo-column information.

Another recipe worth a look include secure client-server communication using the ExtendedSSLSession interface, making use of the keytool, a serverside keystore and a client side trust store.

A new nested class, ProcessBuilder.Redirect, has been introduced to provide redirecting of input and output of external processes – useful for interacting with other executables and scripts.

I think chapter 9 is another chapter all developers will want to read.

Chapter 10's recipes deal with further concurrency enhancements to the Java language, which have been getting more and more powerful since Java 5. The new fork/join framework allows a task to be split into smaller parallelisable chunks, and then combining the results.

Other useful recipes in this chapter demonstrate using the new ThreadLocalRandom class for more efficient random number generation in a threaded environment. And the ConcurrentLinkedDeque example shows how concurrent threads can safely access the same collection data.

Chapter 11 contains bit and bobs which don't fit in other chapters. The Handling null references recipe introduces the new Objects class which provides utility methods for object comparison, null checking and hashing.

The JavaBean enhancements recipe shows how to use the new Expression class to programatically create and execute Java statements. Also the Introspector and BeanInfo class provide a new way of determining a classes' methods and fields without using the Reflection API.

Overall, I think this book is good in places, but repetitive and difficult to work though in others. About half the book is devoted to paths, files, filesystems and I/O, which I'm sure could be slimmed down a bit. I'd recommend using the book as a reference to consult rather than a book to pick up and read cover to cover.  Java 7 New Features Cookbook is definitely worth a read, and I will be using the things I've learned from it in future blog posts.

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