During the applet loading process, some plug-in resources files are requested through ClassLoader.getResource, since deploy.jar and plug-in jar are appended to the end of the boot classpath (BCP), so every jar files in BCP will be opened to search these non-existent resources (non-existent means it does not exist in these jar files before deploy.jar and plugin.jar, e.g. charsets.jar). These resources file name starts with sun/plugin usually. Meta-index will not help in this case since it just puts "sun" (same as "java" & "javax") to the meta-index file. We need to add more resolutions to these entries. However, for rt.jar file, it may contain dozens of these entries, so it will increase the size of meta-index file significantly which may result into the footprint increase. The soultion would be to add sun/XXX entries when the jar file contain less than a certain number of such entries.

Experiments shows the cold-start for a simple applet may decrease up to 2% which is trivial, but theorectically this is a healthy change to avoid jar files not to be opened unnecessarily especially if we decide to split rt.jar into more jar files which will result into more small jar files to be opened unnecessarily.

Warm startup won't be affected by this change based on the experiments.