Hello,
For future CSR requests involving system properties, please document the
properties using these javadoc facilities.
Thanks,
-Joe
On 11/14/2018 2:27 PM, Jonathan Gibbons wrote:
This is an FYI to announce some initial, long-overdue support in
javadoc for documenting system properties (JDK-5076751).
Currently, system properties are just documented using ad-hoc
narrative text, which is fine if you know where to look for any given
property.
JDK 12 introduces a new inline javadoc tag, {@systemProperty
/property-name/} which can be used to "declare" the name of a system
property. You can use this tag as a drop-in replacement for the
plain-text property name; it will have no overt effect on the
narrative text, but it will cause the property name to be put into the
search index and the A-Z index. Thus, property names will become
searchable, to allow users to easily find the definition of any such
system property.
Adding support into javadoc is only part of the story. Now that the
support is in javadoc, we want to update the API documentation, so
that the documentation is updated for all Java SE and JDK system
properties.
Where should the tag be used? The tag should be used in the text of
the defining instance of the property. This is where the
characteristics of the system property are described, which may
include information like: "what is the property for", "how and when is
it set", "can it be modified", and so on. For example, it could be
used in the docs for System.getProperties [1] or Networking Properties
[2] In general, it should -not- be used in situations that merely
refer to the system property by name. For example, the docs for
Path.toAbsolutePath [3] make a reference to the system property
user.dir, but that is not a definition of the property.
Going forward, in future releases, we expect to explore some
enhancements to this feature. Here are some of the ideas that have
been suggested:
* Create a "summary page" that lists all the system properties. This
would be somewhat similar to the current top-level "Constant Values"
page.
* Add information regarding the "scope" of the definition: is it
defined by the Java SE specification, or JDK, or JavaFX, etc. This
information could be used to organize the content on the summary page.
* Update @see and {@link} to be able to refer to system properties.
* Allow a short description to be included in the {@systemProperty}
tag. This text could be included in the search index, the A-Z index,
and the summary page.
-- Jon
[1]:
https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/lang/System.html#getProperties()
[2]:
https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/net/doc-files/net-properties.html
[3]:
https://docs.oracle.com/en/java/javase/11/docs/api/java.base/java/nio/file/Path.html#toAbsolutePath()