Running java with JAVA_OPTS env variable

问题:

In a shell script, I have set the JAVA_OPTS environment variable (to enable remote debugging and increase memory), and then I execute the jar file as follows:

export JAVA_OPTS="-Xdebug -Xrunjdwp:transport=dt_socket,address=8001,server=y,suspend=n -Xms512m -Xmx512m"
java -jar analyse.jar $*

But it seems there is no effect of the JAVA_OPTS env variable as I cannot connect to remote-debugging and I see no change in memory for the JVM.

What could be the problem?

PS: I cannot use those settings in the java -jar analyse.jar $* command because I process command line arguments in the application.

回答1:

I don't know of any JVM that actually checks the JAVA_OPTS environment variable. Usually this is used in scripts which launch the JVM and they usually just add it to the java command-line.

The key thing to understand here is that arguments to java that come before the -jar analyse.jar bit will only affect the JVM and won't be passed along to your program. So, modifying the java line in your script to:

java $JAVA_OPTS -jar analyse.jar $*

Should "just work".

回答2:

You can setup _JAVA_OPTIONS instead of JAVA_OPTS. This should work without $_JAVA_OPTIONS.