2 回答
as oracle says: http://docs.oracle.com/javase/7/docs/webnotes/tsg/TSG-Desktop/html/plugin.html.
following environment variable should be set to add additional arguments to applets:
_JPI_VM_OPTIONS=-Xmx…
Moreover as the reffered site says:
Please note that you need to restart your browser after you set the environment variable. If you are setting this environment variable in the command shell, then you must use the same command shell to launch the browser so that the browser inherits the value of environment variable.
However if you doubt how to set environment variable in ubuntu, following post might be helpful: Make $JAVA_HOME easily changable in Ubuntu
I just had a look at the source code of the icedtea-web plugin. The part of the code which builds the command line seems to have no provision at all for including custom arguments, no matter their origin. So it does not matter which config files, HTML files or environment variables I edit, the code there will build the same command line to call java, disregarding all my whishes.
So if all configuration fails, what remains is hackery. One approach would be to patch the source code of the plugin, and make it include additional words into its command line. For a static addition, i.e. a single size change, this would be fairly easy. A more general fix would include the content of some environment variable, the way Peter's answer suggests. That would mean word-splitting the environment variable in question, and allocating the space for the array of words dynamically. Quite a bit of work at the C level.
As an alternative, one could tackle this at the level of the executed binary. The plugin apparently has the path of the executable hard-coded into it. In my case, this path is /usr/lib/jvm/java-6-openjdk-amd64/jre/bin/java. One can rename that binary to java.orig, and put a shell script in its place, with the following content:
#!/bin/bash
for i in "$@"; do
if [[ "${i}" == sun.applet.PluginMain ]]; then
exec "$0.orig" -Xmx512m "$@"
fi
done
exec "$0.orig" "$@"
One consequence of this approach is the fact that ps will no longer print these applets as java but instead as java.orig. Should not be a problem in most cases.