001 // Copyright (c) 2011, Mike Samuel
002 // All rights reserved.
003 //
004 // Redistribution and use in source and binary forms, with or without
005 // modification, are permitted provided that the following conditions
006 // are met:
007 //
008 // Redistributions of source code must retain the above copyright
009 // notice, this list of conditions and the following disclaimer.
010 // Redistributions in binary form must reproduce the above copyright
011 // notice, this list of conditions and the following disclaimer in the
012 // documentation and/or other materials provided with the distribution.
013 // Neither the name of the OWASP nor the names of its contributors may
014 // be used to endorse or promote products derived from this software
015 // without specific prior written permission.
016 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
017 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
018 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
019 // FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
020 // COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
021 // INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
022 // BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
023 // LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
024 // CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
025 // LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
026 // ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
027 // POSSIBILITY OF SUCH DAMAGE.
028
029 package org.owasp.html;
030
031 import com.google.common.base.Throwables;
032
033 /**
034 * Receives notification of problems.
035 *
036 * @author Mike Samuel <mikesamuel@gmail.com>
037 */
038 public interface Handler<T> {
039
040 void handle(T x);
041
042 /** A handler that does nothing given any input. */
043 public static final Handler<Object> DO_NOTHING = new Handler<Object>() {
044 public void handle(Object x) {
045 // Really, do nothing.
046 }
047 };
048
049 /**
050 * A handler that re-raises an error, wrapping it in a runtime exception if
051 * necessary.
052 */
053 public static final Handler<Throwable> PROPAGATE = new Handler<Throwable>() {
054 public void handle(Throwable th) {
055 Throwables.propagate(th);
056 }
057 };
058 }