Issue #3840 - Adding Default FileSystem check to PathResource

+ Construction of PathResource now tests if path belongs
  to the Default FileSystem or not.  This important info
  for later actions against the PathResource that would
  need to know the File object for the Path object.
  Non-Default FileSystem == null
  Default FileSystem == Path.toFile()

Signed-off-by: Joakim Erdfelt <joakim.erdfelt@gmail.com>

jetty-util/src/main/java/org/eclipse/jetty/util/resource/PathResource.java

@@ -28,6 +28,7 @@ import java.net.URL;
 import java.nio.channels.ReadableByteChannel;
 import java.nio.file.DirectoryIteratorException;
 import java.nio.file.DirectoryStream;
+import java.nio.file.FileSystems;
 import java.nio.file.Files;
 import java.nio.file.InvalidPathException;
 import java.nio.file.LinkOption;
@@ -56,6 +57,7 @@ public class PathResource extends Resource
     private final Path path;
     private final Path alias;
     private final URI uri;
+    private final boolean belongsToDefaultFileSystem;
 
     private final Path checkAliasPath()
     {
@@ -194,6 +196,7 @@ public class PathResource extends Resource
         assertValidPath(path);
         this.uri = this.path.toUri();
         this.alias = checkAliasPath();
+        this.belongsToDefaultFileSystem = this.path.getFileSystem() == FileSystems.getDefault();
     }
 
     /**
@@ -214,6 +217,7 @@ public class PathResource extends Resource
             childPath += "/";
         this.uri = URIUtil.addPath(parent.uri, childPath);
         this.alias = checkAliasPath();
+        this.belongsToDefaultFileSystem = this.path.getFileSystem() == FileSystems.getDefault();
     }
 
     /**
@@ -254,6 +258,7 @@ public class PathResource extends Resource
         this.path = path.toAbsolutePath();
         this.uri = path.toUri();
         this.alias = checkAliasPath();
+        this.belongsToDefaultFileSystem = this.path.getFileSystem() == FileSystems.getDefault();
     }
 
     /**
@@ -363,6 +368,8 @@ public class PathResource extends Resource
     @Override
     public File getFile() throws IOException
     {
+        if (!belongsToDefaultFileSystem)
+            return null;
         return path.toFile();
     }
 

jetty-util/src/test/java/org/eclipse/jetty/util/resource/PathResourceTest.java

@@ -18,6 +18,7 @@
 
 package org.eclipse.jetty.util.resource;
 
+import java.io.File;
 import java.io.IOException;
 import java.io.InputStream;
 import java.net.URI;
@@ -88,4 +89,36 @@ public class PathResourceTest
             }
         }
     }
+
+    @Test
+    public void testNonDefaultFileSystem_GetFile() throws URISyntaxException, IOException
+    {
+        Path exampleJar = MavenTestingUtils.getTestResourcePathFile("example.jar");
+
+        URI uri = new URI("jar", exampleJar.toUri().toASCIIString(), null);
+        System.err.println("URI = " + uri);
+
+        Map<String, Object> env = new HashMap<>();
+        env.put("multi-release", "runtime");
+
+        try (FileSystem zipfs = FileSystems.newFileSystem(uri, env))
+        {
+            Path manifestPath = zipfs.getPath("/META-INF/MANIFEST.MF");
+            assertThat(manifestPath, is(not(nullValue())));
+
+            PathResource resource = new PathResource(manifestPath);
+            File file = resource.getFile();
+            assertThat("File should be null for non-default FileSystem", file, is(nullValue()));
+        }
+    }
+
+    @Test
+    public void testDefaultFileSystem_GetFile() throws Exception
+    {
+        Path exampleJar = MavenTestingUtils.getTestResourcePathFile("example.jar");
+        PathResource resource = new PathResource(exampleJar);
+
+        File file = resource.getFile();
+        assertThat("File for default FileSystem", file, is(exampleJar.toFile()));
+    }
 }