Beet. Dobbs Code Talk - File IO in Java. My Favorite Hotspot JVM Flags. I probably start up a JVM a thousand times a day.
Test runs, benchmark runs, bug confirmation, API exploration, or running actual apps. And in many of these runs, I use various JVM switches to tweak performance or investigate runtime metrics. Here's a short list of my favorite JVM switches (note these are Hotspot/OpenJDK/SunJDK switches, and may or may not work on yours. Apple JVM is basically the same, so these work). The Basics. Ubuntu : Intel® Q6600® quad-core Computer Language Benchmarks Game. Perf4J 0.9.7 - Java Performance Lib. This guide describes how to incorporate Perf4J timing statements into your code, and how to use and enable various Perf4J tools to analyze and visualize the generated performance data.
To run the examples you'll need to download the Perf4J jar file and place it in your classpath. Some of the the Perf4J tools require additional dependencies (for example, the custom log4j appenders require the log4j jar to also be in your classpath). The examples shown will specify these additional dependencies when necessary.