I have a java webstart application with many dependency jars(about 20), it starts up quickly in the development environment as a standalone app. However when it's deployed in java webstart, the start up time is slow(1 minute or so). Is there a way to improve the startup time?
Try this if you are starting Java Web Start app from Windows XP or Windows 7.
Go to java control panel. Under "General" tab open "Network Settings" and choose "Direct connection" instead of "Use browser settings".
"User browser settings" is the default on fresh java install.
When I was using java web start (I didn't look into why), this made it launch 5 to 10 times faster. Tested on couple Windows XP and Windows 7 using both Java 6 and Java 7.
来源：https://stackoverflow.com/questions/11149011/java-webstart-application-startup-time-too-slow