Java Performance Tuning

This book analyzes what it is that makes many Java programs slow and what can be done to speed them up. Many of the examples exhibit speed increases of 20x-100x! Mr. Shirazi doesn't just talk about optimizing your switch statements so they use the table-lookup version of the bytecode (although that is covered), which is one of the low-level optimizations that will sometimes double the speed of a critical section, but also shows how to implement more profound algorithmic optimizations - the kind that can give order-of-magnitude speedups or better.Memory management is covered, including excellent coverage of object creation, what the overhead REALLY is, how to reduce it by reusing objects, avoiding primitive wrapper classes, and other optimizations.There is also suberb advice on algorithms (sorting, searching, data structures), I/O, multithreading (LOTS of fun, as always), character encoding optimization, and the fascinating but complex world of distributed computing.A good distinction is made between the kinds of optimizations that are simply good coding practices and should be practiced regularly (such as using StringBuffers instead of Strings with the + operator) and those that, while being good for performance, are bad for design and increase maintenance costs. So Mr. Shirazi shows us that we can never know what will be slow until we profile, profile, profile. And the profiling done throughout the book doesn't use expensive commercial products, but simple timing code discussed in the first couple chapters.Overall, a book I very much enjoyed reading and I highly recommend it.

This book is diverse in it's approach to java performance tuning. It is very good at describing common bottlenecks in detail and providing concrete examples of how to write better performing code.It has good coverage of topics including Object creation, I/O and sorting. It illustrates efficient ways to write loops and switches and provides insight into the performance costs of exceptions and casts. 'Java Performance Tuning' also shows how to implement class specific collection classes among other topics.It takes a comprehensive look at the java profiling tools available and gives illustrated advantages of applying specific techniques. Performance results are contrasted for the various JVMs (JDK1.2 with and without JIT, JDK1.3, Hotspot 1.0).'Java Performance Tuning' has improved my programming and will sit on my shelf as an excellent reference I know I can turn to if asked to tune a Java application.

Java Performance Tuning reveals how techniques such as minimizing object creation, replacing strings with arrays, and other techniques can improve code performance. Author and Java expert Jack Shirazi also offers common-sense advice about what to tune and what to leave alone in order to maximize performance while avoiding damaging a program's architecture. Highly recommended as both an instruction manual Java users, Java Performance Tuning is a very well presented, highly recommend, "user friendly" reference that is enhanced with performance tuning checklists enabling developers to make their tuning as comprehensive and effective as possible.

We used about a dozen of the techniques from the book and our component went from being a real dog to way fast enough. Given what we achieved with the basic techniques, most of the more advanced techniques are unlikely to ever be used by us, but they were interesting and might come in useful one day. The book paid for itself within a day. Definitely useful if you have or anticipate a performance problem.

The book ranges rather widely, covering a huge number of tuning details. The author seems to know hands-on performance tuning very well, and many of the examples were directly applicable to our own development. There is only one chapter on designing for performance (I would have liked more), but in that chapter he did identify precisely the issues that we encountered in our project. The example of double sorting internationalized text transferred directly to our project and speeded up a crucial area of our presentation. I do recommend this book, but do not expect a design book. This is strongly hands-on performance tuning.