Performance has been an important issue for Java developers ever since the first version hit the streets. Over the years, Java performance has improved dramatically, but tuning is essential to get the best results, especially for J2EE applications. You can never have code that runs too fast.Java Peformance Tuning, 2nd edition provides a comprehensive and indispensable guide to eliminating all types of performance problems. Using many real-life examples to work through the tuning process in detail, JPT shows how tricks such as minimizing object creation and replacing strings with arrays can really pay off in improving your code's performance.Tuning J2EE applications bears many similarities to tuning J2SE apps, but important and specific considerations apply. For this reason, Java Performance Tuning, Second Edition includes four new chapters: a new chapter on J2EE application tuning in general followed by chapters on tuning JDBC, servlets and JSPs, and EJBs.Java Performance Tuning offers common-sense advice about what to tune and what to leave alone, emphasizing techniques that provide big performance gains with minimal code restructuring. It gives you crucial guidance that helps you tune without destroying your program's architecture. Blindly changing things in an effort to make a program run faster is a great way to create buggy, unmaintainable code. Java Performance Tuning teaches you to work efficiently and effectively, resulting in code that is robust, maintainable, and fast.Java Performance Tuning, Second Edition shows you how to:
- Create a performance plan
- Glean information about your program's behavior from profiling tools
- Identify bottlenecks before tuning
- Minimize the number of objects your program creates, particularly critical for J2EE applications
- Optimize the use of strings
- Avoid performance penalties from inefficient code
- Improve the behavior of loops and switches
- Optimize I/O behavior
- Use appropriate algorithms for sorting and other common tasks
- Use threads effectively
- Optimize the performance of distributed systems
- Speed up servlets and JSPs
- Structure JDBC usage efficiently
- Use effective design patterns to optimize EJB performance
Covers JDK 1.4
Java applications are often seen as slower than native code apps--it's part of the cost of platform independence and ease of use. However, there are speed-up techniques modern coders ignore with fast CPUs and huge memories to cover for them.
Java Performance Tuning covers techniques applicable to coding in any programming language with those specific to not just Java but particular versions. Shirazi starts with an illuminating discussion of real speed versus the user's perception of speed, threading, caching, streaming, bench-marking and choosing what to measure.
Examples of generally applicable speed-up techniques include obvious examples such as moving unnecessary calculations to the outside of loops while Java-specific techniques include avoiding garbage collection. Some techniques are also applicable with other object-oriented languages; for example, reusing objects instead of recreating them.
The text is clear and readable. Everything discussed is shown as code examples with percentage timings to give an idea of the gains you can make. There is also extensive discussion on choosing algorithms.
Shirazi's coverage of distributed programs is particularly enlightening as they suffer from different bottlenecks, at least from a user point of view. Making a user feel the program is faster is often more a matter of retaining the user's attention than actually increasing speed--the Internet, for example, is unlikely to respond to code enhancements.
Because a better understanding of the way your programs work also makes for greater memory efficiency, more robustness and a better user experience--as well as more speed--this book will dramatically improve your programs. --Steve Patient
