8259519: The java.awt.datatransfer.DataFlavor#ioInputStreamClass field is redundant

Reviewed-by: aivanov

src/java.datatransfer/share/classes/java/awt/datatransfer/DataFlavor.java

@@ -117,7 +117,6 @@ public class DataFlavor implements Externalizable, Cloneable {
      */
     @Serial
     private static final long serialVersionUID = 8367026044764648243L;
-    private static final Class<InputStream> ioInputStreamClass = InputStream.class;
 
     /**
      * Tries to load a class from: the bootstrap loader, the system loader, the
@@ -1144,7 +1143,7 @@ public class DataFlavor implements Externalizable, Cloneable {
      * @return the default representation class
      */
     public final Class<?> getDefaultRepresentationClass() {
-        return ioInputStreamClass;
+        return java.io.InputStream.class;
     }
 
     /**
@@ -1163,7 +1162,7 @@ public class DataFlavor implements Externalizable, Cloneable {
      *         {@code java.io.InputStream}
      */
     public boolean isRepresentationClassInputStream() {
-        return ioInputStreamClass.isAssignableFrom(representationClass);
+        return java.io.InputStream.class.isAssignableFrom(representationClass);
     }
 
     /**

test/jdk/java/awt/datatransfer/DataFlavor/DefaultRepresentation.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+import java.awt.datatransfer.DataFlavor;
+import java.io.InputStream;
+
+/**
+ * @test
+ * @bug 8259519
+ * @summary InputStream should be used as a default data flavor representation
+ */
+public final class DefaultRepresentation extends InputStream {
+
+    public static void main(String[] args) {
+        DataFlavor df = new DataFlavor(DefaultRepresentation.class, "stream");
+        if (df.getDefaultRepresentationClass() != InputStream.class) {
+            // default representation class is not specified!
+            // this check just defends against accidental changes
+            throw new RuntimeException("InputStream class is expected");
+        }
+        if (!df.isRepresentationClassInputStream()) {
+            throw new RuntimeException("true is expected");
+        }
+    }
+
+    @Override
+    public int read() {
+        return 0;
+    }
+}