/**
 * Copyright (c) 2010, Ben Fortuna
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *  o Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 *  o Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 *  o Neither the name of Ben Fortuna nor the names of any other contributors
 * may be used to endorse or promote products derived from this software
 * without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package net.fortuna.ical4j.util;

import java.util.HashMap;
import java.util.Map;

/**
 * $Id$
 * 
 * Created on 9/03/2006
 * 
 * A set of keys used to enable compatibility features.
 * 
 * @author Ben Fortuna
 */
public final class CompatibilityHints {

    /**
     * A system property key to enable relaxed unfolding. Relaxed unfolding is enabled by setting this system property
     * to "true".
     */
    public static final String KEY_RELAXED_UNFOLDING = "ical4j.unfolding.relaxed";

    /**
     * A system property key to enable relaxed parsing. Relaxed parsing is enabled by setting this system property to
     * "true".
     */
    public static final String KEY_RELAXED_PARSING = "ical4j.parsing.relaxed";

    /**
     * A system property key to enable relaxed validation. Relaxed validation disables validation of certain conformance
     * rules that many iCalendar implementations do not conform to. Relaxed validation is enabled by setting this system
     * property to "true".
     */
    public static final String KEY_RELAXED_VALIDATION = "ical4j.validation.relaxed";

    /**
     * A system property key used to enable compatibility with Outlook/Exchange-generated iCalendar files. Outlook
     * compatibility is enabled by setting this system property to "true".
     */
    public static final String KEY_OUTLOOK_COMPATIBILITY = "ical4j.compatibility.outlook";

    /**
     * A system property key used to enable compatibility with Lotus Notes-generated iCalendar files. Notes
     * compatibility is enabled by setting this system property to "true".
     */
    public static final String KEY_NOTES_COMPATIBILITY = "ical4j.compatibility.notes";

    private static final ThreadLocal HINTS = new ThreadLocal() {
        protected Object initialValue() {
            return new HashMap();
        }
    };

    /**
     * Constructor made private to enforce static nature.
     */
    private CompatibilityHints() {
    }

    /**
     * @param key
     *            a compatibility hint key
     * @param enabled
     *            indicates whether to enable or disable the compatibility hint
     */
    public static void setHintEnabled(final String key, final boolean enabled) {
        ((Map) HINTS.get()).put(key, Boolean.valueOf(enabled));
    }

    /**
     * @param key
     *            a compatibility hint key
     */
    public static void clearHintEnabled(final String key) {
        ((Map) HINTS.get()).remove(key);
    }

    /**
     * @param key
     *            a compatibility hint key
     * @return true if the specified compatibility hint is enabled, otherwise false
     */
    public static boolean isHintEnabled(final String key) {
        if (((Map) HINTS.get()).get(key) != null) {
            return ((Boolean) ((Map) HINTS.get()).get(key)).booleanValue();
        }
        return "true".equals(Configurator.getProperty(key));
    }
}

@@ -1616,34 +1616,82 @@
 til.
-Hash
 Map;%0A
+%0A
 import 
-java.util.
+edu.emory.mathcs.backport.java.util.concurrent.ConcurrentHash
 Map;
@@ -3311,27 +3311,19 @@
 c final 
-ThreadLocal
+Map
  HINTS =
@@ -3331,115 +3331,27 @@
 new 
-ThreadLocal() %7B%0A        protected Object initialValue() %7B%0A            return new HashMap();%0A        %7D%0A    %7D
+ConcurrentHashMap()
 ;%0A%0A 
@@ -3733,35 +3733,21 @@
         
-((Map) HINTS.get())
+HINTS
 .put(key
@@ -3927,35 +3927,21 @@
         
-((Map) HINTS.get())
+HINTS
 .remove(
@@ -4186,35 +4186,21 @@
     if (
-((Map) HINTS.get())
+HINTS
 .get(key
@@ -4246,27 +4246,13 @@
 an) 
-((Map) HINTS.get())
+HINTS
 .get

Use a concurrent map instead of thread local to avoid memory leak in web containers