RFR(m): 8145468 deprecations for java.lang

Chris Hegarty chris.hegarty at oracle.com
Fri Apr 15 18:14:44 UTC 2016

Partial review. The changes to j.l.Thread* look good to me.


On 14 Apr 2016, at 02:50, Stuart Marks <stuart.marks at oracle.com> wrote:

> Hi all,
> Please review this first round of deprecation changes for the java.lang package. This changeset includes the following:
> - a set of APIs being newly deprecated
> - a set of already-deprecated APIs that are "upgraded" to forRemoval=true
> - addition of the "since" element to all deprecations
> - cleanup of some of the warnings caused by new deprecations
> Webrevs:
>  http://cr.openjdk.java.net/~smarks/reviews/8145468/webrev.0.jdk/
>  http://cr.openjdk.java.net/~smarks/reviews/8145468/webrev.0.langtools/
>  http://cr.openjdk.java.net/~smarks/reviews/8145468/webrev.0.top/
> The newly deprecated APIs include all of the constructors for the boxed primitives. We don't intend to remove these yet, so they don't declare a value for the forRemoval element, implying the default value of false. The constructors being deprecated are as follows:
>  Boolean(boolean)
>  Boolean(String)
>  Byte(byte)
>  Byte(String)
>  Character(char)
>  Double(double)
>  Double(String)
>  Float(float)
>  Float(double)
>  Float(String)
>  Integer(int)
>  Integer(String)
>  Long(long)
>  Long(String)
>  Short(short)
>  Short(String)
> The methods being deprecated with forRemoval=true are listed below. All of these methods have already been deprecated. They are all ill-defined, or they don't work, or they don't do anything useful.
>  Runtime.getLocalizedInputStream(InputStream)
>  Runtime.getLocalizedOutputStream(OutputStream)
>  Runtime.runFinalizersOnExit(boolean)
>  SecurityManager.checkAwtEventQueueAccess()
>  SecurityManager.checkMemberAccess(Class<?>, int)
>  SecurityManager.checkSystemClipboardAccess()
>  SecurityManager.checkTopLevelWindow(Object)
>  System.runFinalizersOnExit(boolean)
>  Thread.countStackFrames()
>  Thread.destroy()
>  Thread.stop(Throwable)
> Most of the files in the changeset are cleanups. Some of them are simply the addition of the "since" element to the @Deprecated annotation, to indicate the version in which the API became deprecated.
> The rest of the changes are cleanup of warnings that were created by the deprecation of the boxed primitive constructors. There are a total of a couple hundred such uses sprinkled around the JDK. I've taken care of a portion of them, with the exception of the java.desktop module, which alone has over 100 uses of boxed primitive constructors. I've disabled deprecation warnings for the java.desktop module for the time being; these uses can be cleaned up later. I've filed JDK-8154213 to cover this cleanup task.
> For the warnings cleanups I did, I mostly did conversions of the form:
>   new Double(dval)
> to
>   Double.valueOf(dval)
> This is a very safe transformation. It changes the behavior only in the cases where the code relies on getting a new instance of the box object instead of one that might come out of a cache. I didn't see any such code (and I should hope there's no such code in the JDK!).
> I applied autoboxing only sparingly, in the cases where it was an obviously safe thing to do, or where nearby code already uses autoboxing. Autoboxing actually generates a call to the appropriate valueOf() method, so the bytecode would be the same in most cases. The only difference is clutter in the source code. On the other hand, there's some risk in converting to autoboxing, as the implicitly autoboxed type might end up different from an explicit call to valueOf(). This isn't always obvious, so that's why I mostly avoided autoboxing.
> Thanks,
> s'marks

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