RELEASE NOTES: JDK 13.0.12

`java.net.FileNameMap.getContentTypeFor(fileName)` May Return a Different MIME Type for Certain Filenames

The default, built-in filename map in the JDK has been updated to include additional filename to MIME type mappings. Along with the additions, existing mappings of .gz and .zip have also been updated. This can result in the default, built-in java.net.FileNameMap instance returning a different MIME type from the getContentTypeFor(String fileName) method than what it returned in previous JDK releases.

java.net.URLConnection.guessContentTypeFromName(String fname), which may use this default, built-in FileNameMap instance, thus may return a different value than previously.

New System Property to Disable Windows Alternate Data Stream Support in java.io.File

The Windows implementation of java.io.File allows access to NTFS Alternate Data Streams (ADS) by default. Such streams have a structure like “filename:streamname”. A system property jdk.io.File.enableADS has been added to control this behavior. To disable ADS support in java.io.File, the system property jdk.io.File.enableADS should be set to false (case ignored). Stricter path checking however prevents the use of special devices such as NUL:

Default JDK Compressor Will Be Closed when IOException Is Encountered

DeflaterOutputStream.close() and GZIPOutputStream.finish() methods have been modified to close out the associated default JDK compressor before propagating a Throwable up the stack. ZIPOutputStream.closeEntry() method has been modified to close out the associated default JDK compressor before propagating an IOException, not of type ZipException, up the stack.