Please review -XshowSettings a java launcher option.

Mandy Chung mandy.chung at
Thu Nov 11 23:09:46 UTC 2010

  On 11/11/10 13:56, Kumar Srinivasan wrote:
> Hi All,
> Please review the following:

Some comments:

line 1031: this doesn't catch invalid option if it has the 
-XshowSettings prefix e.g. -XshowSettingsJunk.
line 1032: Perhaps you could store the suboption ("all", "vm", etc) 
rather than the entire option string.
line 1507-1511: should these lines align with the argument "env"  to 
CallStaticVoidMethod method in line 1506?
line 106-109: if optionFlag is just the suboption to -XshowSettings, 
these lines can be removed.
line 150-152: Runtime.maxMemory() is not equivalent to -Xmx value.  
Perhaps -XshowSettings always prints Runtime.maxMemory() and print -Xmx 
if set in the command line?

line 176, 188, 190-191, 195, and other lines in printPrintLocales and 
printLocale methods:
- the assignment to the buf and out variable to itself (returned from 
StringBuffer.append() method) is not necessary.

line 174: would it be better to pass the StringBuilder to the 
printPrintValue method so that it can avoid creating a new StringBuilder 
instance for each property?

line 213-214: same comment as the above.   And should it use 
StringBuilder instead?

> This will print all the known settings/properties/locales
> supported and known  to Java, this has  been a long standing request.
> A sample output attached below.
> Note: the -X option specifically is being used so we can evolve this 
> option
> and add more useful information, in future versions of java.
> Thanks
> Kumar

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