JDK 9 RFR of 8146215: (fs) java/nio/file/Files/probeContentType/Basic.java failed frequently on Solaris-sparc with Unexpected type: text/plain

[Roger Riggs]

Hi Brian,

+1

Basic.java: Line 69:  (pre-existing) Its probably useful to include the 
message from the exception,
        it may provide some clue as to what the problem was.


On 8/1/2016 6:11 PM, Brian Burkhalter wrote:
> On Jul 30, 2016, at 2:31 AM, Alan Bateman <Alan.Bateman at oracle.com 
> <mailto:Alan.Bateman at oracle.com>> wrote:
>
>> The synchronization doesn't look right in 
>> FileNameMapFileTypeDetector. As fileNameMap is static then 
>> synchronized (this) { ... } doesn't do what you intend.
>
> Thanks, that was a mistake in creating this class from the code of the 
> previous NetFileTypeDetector class.
>
>> It's not an issue if URLConnection.getFileNameMap() is invoked more 
>> than once so I think you can reduce this down to:
>>
>> FileNameMap map = fileNameMap;
>> if (map == null) {
>>    fileNameMap = map = URLConnection.getFileNameMap();
>> }
>> return map.getContentTypeFor(…);
>
> Modified accordingly: 
> http://cr.openjdk.java.net/~bpb/8146215/webrev.02/ 
> <http://cr.openjdk.java.net/%7Ebpb/8146215/webrev.02/>
>
>> Alternatively just call URLConnection.getFileNameMap() each time.
>
> URLConnection.getFileNameMap() is synchronized and returns a new 
> anonymous class instance at each invocation so this does not look to 
> be a good idea.
>
>> As regards ordering what what you have it okay. I assume it will be 
>> rare to set the property content.types.user.table and so the JDK's 
>> content-types.properties will be a fallback.
>
> Question is whether this should be a fallback on OS X and Windows as well.
+1 that would provide a consistent cross-platform fallback based on the 
system property "content.types.user.table".

Roger

>
> Thanks,
>
> Brian