--- a/src/jdk.zipfs/share/classes/jdk/nio/zipfs/ZipFileSystemProvider.java	Fri Oct 04 15:51:17 2019 -0400
+++ b/src/jdk.zipfs/share/classes/jdk/nio/zipfs/ZipFileSystemProvider.java	Sun Oct 06 13:08:58 2019 -0400
@@ -53,6 +53,11 @@
  */
 public class ZipFileSystemProvider extends FileSystemProvider {
 
+    // Property used to specify the entry version to use for a multi-release JAR
+    static final String PROPERTY_RELEASE_VERSION = "releaseVersion";
+    // Original property used to specify the entry version to use for a
+    // multi-release JAR which is kept for backwards compatibility.
+    static final String PROPERTY_MULTI_RELEASE = "multi-release";
     private final Map<Path, ZipFileSystem> filesystems = new HashMap<>();
 
     public ZipFileSystemProvider() {}
@@ -104,20 +109,7 @@
                 if (filesystems.containsKey(realPath))
                     throw new FileSystemAlreadyExistsException();
             }
-            ZipFileSystem zipfs;
-            try {
-                if (env.containsKey("multi-release")) {
-                    zipfs = new JarFileSystem(this, path, env);
-                } else {
-                    zipfs = new ZipFileSystem(this, path, env);
-                }
-            } catch (ZipException ze) {
-                String pname = path.toString();
-                if (pname.endsWith(".zip") || pname.endsWith(".jar"))
-                    throw ze;
-                // assume NOT a zip/jar file
-                throw new UnsupportedOperationException();
-            }
+            ZipFileSystem zipfs = getZipFileSystem(path, env);
             if (realPath == null) {  // newly created
                 realPath = path.toRealPath();
             }
@@ -131,20 +123,25 @@
         throws IOException
     {
         ensureFile(path);
+        return getZipFileSystem(path, env);
+    }
+
+    private ZipFileSystem getZipFileSystem(Path path, Map<String, ?> env) throws IOException {
+        ZipFileSystem zipfs;
         try {
-            ZipFileSystem zipfs;
-            if (env.containsKey("multi-release")) {
+            if (env.containsKey(PROPERTY_RELEASE_VERSION) ||
+                    env.containsKey(PROPERTY_MULTI_RELEASE)) {
                 zipfs = new JarFileSystem(this, path, env);
             } else {
                 zipfs = new ZipFileSystem(this, path, env);
             }
-            return zipfs;
         } catch (ZipException ze) {
             String pname = path.toString();
             if (pname.endsWith(".zip") || pname.endsWith(".jar"))
                 throw ze;
             throw new UnsupportedOperationException();
         }
+        return zipfs;
     }
 
     @Override