Zip file system provider only works with default file system

[Xueming Shen]

ZFS tries to create a temporary file at the same directory as your 
zipfile by invoking
the File.createTempFile(). Unfortunately the directory passed is the one 
on your
in-memory file system in your use scenario. This need to be 
re-considered when
we update the ZFS.

-Sherman


On 12/8/12 5:41 AM, Philippe Marschall wrote:
> On Sat, Dec 8, 2012 at 11:52 AM, Alan Bateman <Alan.Bateman at oracle.com> wrote:
>> On 07/12/2012 23:05, Philippe Marschall wrote:
>>> Hi
>>>
>>> First, I hope I got the right mailing list. I'm in the process of
>>> writing my own file system provider. As a test I wanted to create a
>>> zip file on it using the zip file system provider. That's when I
>>> discovered that it only works with the default file system.
>>>
>> Thanks for the bug report, It's possible that zip provider has been tested
>> with other providers. Is your provider interposing on the system-default or
>> is a distinct provider? I'm curious how you ran into this.
> To give a bit more context my code looks something like this:
>
> public class ZipFileSystemInteropabilityTest {
>
>    @Rule
>    public final FileSystemRule rule = new FileSystemRule();
>
>    @Test
>    public void createZipFileSystem() throws IOException {
>      FileSystem memoryFileSystem = this.rule.getFileSystem();
>      Map<String, String> env = Collections.singletonMap("create", "true");
>      URI uri = URI.create("jar:" +
> memoryFileSystem.getPath("/file.zip").toUri());
>      try (FileSystem zipfs = FileSystems.newFileSystem(uri, env)) {
>        try (BufferedWriter writer =
> Files.newBufferedWriter(zipfs.getPath("hello.txt"),
> StandardCharsets.US_ASCII, CREATE_NEW, WRITE)) {
>          writer.write("world");
>        }
>      }
>    }
>
> }
>
> where memoryFileSystem would be an instance of my custom memory file
> system and the rule would be a JUnit rule that create a file system
> before the test and removes it afterward.
>
> The exception I get is:
>
> java.io.IOException: Permission denied
> 	at java.io.UnixFileSystem.createFileExclusively(Native Method)
> 	at java.io.File.createTempFile(File.java:1879)
> 	at com.sun.nio.zipfs.ZipFileSystem.createTempFileInSameDirectoryAs(ZipFileSystem.java:1087)
> 	at com.sun.nio.zipfs.ZipFileSystem.sync(ZipFileSystem.java:1190)
> 	at com.sun.nio.zipfs.ZipFileSystem.close(ZipFileSystem.java:277)
> 	at com.acme.memoryfilesystem.ZipFileSystemInteropabilityTest.createZipFileSystem(ZipFileSystemInteropabilityTest.java:34)
> 	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
> 	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
> 	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
> 	at java.lang.reflect.Method.invoke(Method.java:601)
> 	at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
> 	at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
> 	at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
> 	at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
> 	at com.acme.memoryfilesystem.FileSystemRule$1.evaluate(FileSystemRule.java:28)
> 	at ..
>
> The problem is that the zip file system provider tries to create a
> temp file like /zipfstmp5062712090450520532.tmp in the default file
> system instead of the file system it's running on. And on Unix you
> generally don't have the permission to create files in the root.
>
> Cheers
> Philippe