--- /dev/null	2018-06-17 23:18:20.806999507 +0800
+++ new/src/share/classes/jdk/jfr/internal/dcmd/DCmdException.java	2019-01-29 10:59:58.895992468 +0800
@@ -0,0 +1,69 @@
+/*
+ * Copyright (c) 2012, 2019, 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.  Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+package jdk.jfr.internal.dcmd;
+
+import java.util.Formatter;
+
+/**
+ * Thrown to indicate that a diagnostic command could not be executed
+ * successfully.
+ */
+final class DCmdException extends Exception {
+    private static final long serialVersionUID = -3792411099340016465L;
+
+    /**
+     * Constructs a new exception with message derived from a format string.
+     *
+     * @param format format string as described in {@link Formatter} class.
+     *
+     * @param args arguments referenced by the format specifiers in the format
+     *        string.
+     *
+     */
+    public DCmdException(String format, Object... args) {
+        super(format(format, args));
+    }
+
+    /**
+     * Constructs a new exception with message derived from a format string.
+     *
+     * @param cause exception that stopped the diagnostic command to complete.
+     *
+     * @param format format string as described in {@link Formatter} class.
+     *
+     * @param args arguments referenced by the format specifiers in the format
+     *        string.
+     *
+     */
+    public DCmdException(Throwable cause, String format, Object... args) {
+        super(format(format, args), cause);
+    }
+
+    private static String format(String message, Object... args) {
+        try (Formatter formatter = new Formatter()) {
+            return formatter.format(message, args).toString();
+        }
+    }
+}