Run the following sample:
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import java.awt.Toolkit;
import java.awt.datatransfer.Clipboard;
import java.awt.datatransfer.DataFlavor;
import java.awt.datatransfer.SystemFlavorMap;
import java.io.IOException;
import java.io.Reader;
import javax.swing.JLabel;
import javax.swing.TransferHandler;

public class ConstructFlavoredObjectTest {

    private static final String TEST_MIME_TYPE = "text/plain;class="
            + MyStringReader.class.getName();

    public static void main(String[] args) throws Exception {

        final DataFlavor dataFlavor = new DataFlavor(TEST_MIME_TYPE);
        SystemFlavorMap systemFlavorMap = (SystemFlavorMap) SystemFlavorMap.
                getDefaultFlavorMap();
        systemFlavorMap.addUnencodedNativeForFlavor(dataFlavor, "TEXT");
        systemFlavorMap.addFlavorForUnencodedNative("TEXT", dataFlavor);

        TransferHandler transferHandler = new TransferHandler("Test Handler");

        Clipboard clipboard = Toolkit.getDefaultToolkit().getSystemClipboard();
        transferHandler.exportToClipboard(new JLabel("Test"), clipboard,
                TransferHandler.COPY);

        Object clipboardData = clipboard.getData(dataFlavor);
        System.out.println("clipboardData: " + clipboardData);
        if (!(clipboardData instanceof MyStringReader)) {
            throw new RuntimeException("Wrong clipboard data!");
        }
    }

    public static class MyStringReader extends Reader {

        public MyStringReader(Reader reader) {
        }

        @Override
        public int read(char[] cbuf, int off, int len) throws IOException {
            throw new UnsupportedOperationException("Not supported yet.");
        }

        @Override
        public void close() throws IOException {
            throw new UnsupportedOperationException("Not supported yet.");
        }
    }
}
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The exception is thrown:
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Exception in thread "main" java.lang.InternalError
at java.lang.invoke.MethodHandleImpl$BindCaller.bindCaller(MethodHandleImpl.java:1144)
at java.lang.invoke.MethodHandleImpl$BindCaller.bindCaller(MethodHandleImpl.java:1144)
at java.lang.invoke.MethodHandleImpl.bindCaller(MethodHandleImpl.java:1130)
at java.lang.invoke.MethodHandles$Lookup.maybeBindCaller(MethodHandles.java:1677)
at java.lang.invoke.MethodHandles$Lookup.getDirectMethodCommon(MethodHandles.java:1665)
at java.lang.invoke.MethodHandles$Lookup.getDirectMethodNoSecurityManager(MethodHandles.java:1613)
at java.lang.invoke.MethodHandles$Lookup.getDirectMethodForConstant(MethodHandles.java:1798)
at java.lang.invoke.MethodHandles$Lookup.linkMethodHandleConstant(MethodHandles.java:1747)
at java.lang.invoke.MethodHandleNatives.linkMethodHandleConstant(MethodHandleNatives.java:399)
at sun.awt.datatransfer.DataTransferer.constructFlavoredObject(DataTransferer.java:1438)
at sun.awt.datatransfer.DataTransferer.translateStream(DataTransferer.java:1361)
at sun.awt.windows.WDataTransferer.translateStream(WDataTransferer.java:237)
at sun.awt.datatransfer.DataTransferer.translateBytes(DataTransferer.java:1190)
at sun.awt.windows.WDataTransferer.translateBytes(WDataTransferer.java:285)
at sun.awt.datatransfer.SunClipboard.getData(SunClipboard.java:230)
at datatransfer.ConstructFlavoredObjectTest.main(ConstructFlavoredObjectTest.java:59)
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