Java Profiling and Monitoring tools
There are many Java development tools available for analyzing Java application run time performance. Eclipse has a set of plug-ins called TPTP which provides Java application profiling/monitoring framework. However, TPTP is very slow and I experienced frequent crash while profiling ICU4J codes. For ICU4J development, I recommend several tools described below.
VisualVM is coming with Sun JDK 6 since update 7. You can download the latest version from here - https://visualvm.dev.java.net/
There is an Eclipse plug-in, which allow you to launch VisualVM when you run a Java app on Eclipse. You can monitor CPU usage of the Java app, Memory usage (heap/permgen), classes loaded, etc in GUI. You can also get basic profiling information, such as CPU usage by class, memory allocations and generate heap dump, force GC etc.
See the page Profiling ICU4J code with NetBeans profiler
NetBeans profiler (formerly known as JFluid) is a great tool for analyzing Java application performance. In the past, when I need to profile ICU4J classes, I created a new NetBeans project and use the profiler to analyze issues. The profiler included in VisualVM is actually a lightweight version of this. I was wondering if we can use the profiler without creating a NetBeans Java project. It looks there are many people wanting to use this profiler from Eclipse IDE. It looks the easiest way to use NetBeans profiler as a standalone app is -
1. Start NetBeans IDE
2. Create a run configuration for a Java application on Eclipse IDE
3. Specify JVM argument to attach NetBeans profiler to the Java process
For example, I use NetBeans 6.7.1. The following JVM argument is specified in the run configuration in my Eclipse workspace.
java -agentpath:"C:\Program Files\NetBeans 6.7.1\profiler3\lib\deployed\jdk16\windows\profilerinterface.dll"="C:\Program Files\NetBeans 6.7.1\profiler3\lib,5140"
4. Run the Java Application on Eclipse IDE - You will see "Profiler Agent: Waiting for connection on port 5140 (Protocol version: 9)" in the console.
5. Go back to NetBeans IDE, then select [Profile] - [Attach Profiler] from the menu. You can select one from Monitor / CPU / Memory.