Is there any site/analysis about what Java version most people are using on WWW ? It seems this data is not available on webserver logs (vs. Flash versions)
Can we safely set e.g. Java 1.4.2 as minimum requirement for our applet, or are there still many users using Java 1.1 (MS one) or Java 1.2-1.3 ?
It's still a bit of a complicated process to update Java if it's too old, e.g. admin rights are needed on Windows machine and it's bit difficult in some Linux distros too.
This chart might help.
From 1,471,010 browsers across 47 sites in the past 30 days...
- 6% had 1.4,
- 16% had 1.5
- 50% had 1.6
http://weblogs.java.net/blog/editors/archives/2009/03/bedbugs_and_bal.html is an article that talks about the chart.
You can modify Google analytics code to detect Java version, see this script.
Regarding Java versions prior to 1.4 there is little available data, I ran my own test in mid February, sampling almost 20,000 visitors who had Java:
Java Number 1.6 15516 79.5% 1.5 2161 11.1% 1.4 685 3.5% 1.3 36 0.2% 1.2 0 0.0% 1.1 1115 5.7% Total 19513 100.0%
Following from this data I finally upped the requirements from 1.1 to 1.4, allowing Swing only a decade after it was released!
You could consider java web start. This allows you to use any recent version you wish. It even allow you to use a version which is older than the default version for a browser. e.g. if you have a program which only works with Java 5 but Java 6 is installed.
来源：https://stackoverflow.com/questions/650582/what-java-versions-are-commonly-installed-on-browsers-is-it-safe-to-assume-1-4