RFR JDK-8066709 Make some JDK system properties read only

[Lance Andersen]

Hi Roger,



In System.java

—————
 <strong>changing any standard system property may have unpredictable effects</strong>.

————————

Perhaps capitalize ‘changing' and maybe consider ‘results’ vs ‘effects’



HTH

Best
Lance
> On Jun 4, 2018, at 3:55 PM, Roger Riggs <Roger.Riggs at Oracle.com> wrote:
> 
> Hi Lance,
> 
> On 6/4/2018 12:09 PM, Lance Andersen wrote:
>> Hi Roger,
>> 
>> Overall, it looks very good.
>> 
>> A couple of quick thoughts, nothing that needs any action unless you feel the desire :-)
>> 
>> Line 671 in System.java, it mentions ‘standard’ system properties.  (as does the existing Implementation note) but it does not really specify what a standard system property is (though it can be assumed) in getProperties overview.  Not a big deal, just thought I would point it out in case you had a alternative thought.
> Yes, it is a bit vague and the documentation of properties is spread over many packages and classes.
> 'Standard' generally refers to any property defined in the scope of Java SE or the documented JDK properties.
> (For example, those subject to the CSR process).
>> 
>> Do you think we should had a mention in getProperty() about this cached properties (or do we think the reference to getProperties() is enough)
> Hard to say,  there will be a release note, but the properties methods are well known and it is
> likely no one reads the javadoc anymore.  getProperty delegates to getProperties for most of its behavior.
> 
> Adding a repeat of the API note to System.setProperties and System.setProperty might be more to the point, 
> warning against setting standard system properties via the API.
> I added the apinote to each of the 6 methods for setting, clearing, or getting properties. If that seems excessive, 
> I'm open to removing it from those that provide the least value.
> 
> Thanks, Roger
> 
>> 
>> Best
>> Lance
>>> On Jun 4, 2018, at 9:32 AM, Roger Riggs <Roger.Riggs at oracle.com <mailto:Roger.Riggs at oracle.com>> wrote:
>>> 
>>> Please review a change to make the values of java.home, user.home, user.dir, and user.name
>>> effectively read-only for internal use.  The values are cached during initialization and the
>>> cached values are used.
>>> 
>>> Webrev:
>>>   http://cr.openjdk.java.net/~rriggs/webrev-static-property-8066709/ <http://cr.openjdk.java.net/%7Erriggs/webrev-static-property-8066709/>
>>> 
>>> Issue:
>>>   https://bugs.openjdk.java.net/browse/JDK-8066709 <https://bugs.openjdk.java.net/browse/JDK-8066709>
>>> 
>>> CSR:
>>>   https://bugs.openjdk.java.net/browse/JDK-8204235 <https://bugs.openjdk.java.net/browse/JDK-8204235>
>>> 
>>> Thanks, Roger
>>> 
>>> 
>> 
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>>  <http://oracle.com/us/design/oracle-email-sig-198324.gif>Lance Andersen| Principal Member of Technical Staff | +1.781.442.2037
>> Oracle Java Engineering 
>> 1 Network Drive 
>> Burlington, MA 01803
>> Lance.Andersen at oracle.com <mailto:Lance.Andersen at oracle.com>
>> 
>> 
>> 
> 

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 <http://oracle.com/us/design/oracle-email-sig-198324.gif>Lance Andersen| Principal Member of Technical Staff | +1.781.442.2037
Oracle Java Engineering 
1 Network Drive 
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Lance.Andersen at oracle.com <mailto:Lance.Andersen at oracle.com>