001// ***************************************************************************************************************************
002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements.  See the NOTICE file *
003// * distributed with this work for additional information regarding copyright ownership.  The ASF licenses this file        *
004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance            *
005// * with the License.  You may obtain a copy of the License at                                                              *
006// *                                                                                                                         *
007// *  http://www.apache.org/licenses/LICENSE-2.0                                                                             *
008// *                                                                                                                         *
009// * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an  *
010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the License for the        *
011// * specific language governing permissions and limitations under the License.                                              *
012// ***************************************************************************************************************************
013package org.apache.juneau.utils;
014
015/**
016 * Stack trace utility methods.
017 */
018public class StackTraceUtils {
019
020   /**
021    * Calculates a 16-bit hash for the specified throwable based on it's stack trace.
022    *
023    * @param t The throwable to calculate the stack trace on.
024    * @param stopClass Optional stop class on which to stop calculation of a stack trace beyond when found.
025    * @return A calculated hash.
026    */
027   public static int hash(Throwable t, String stopClass) {
028      int i = 0;
029      while (t != null) {
030         for (StackTraceElement e : t.getStackTrace()) {
031            if (e.getClassName().equals(stopClass))
032               break;
033            if (e.getClassName().indexOf('$') == -1)
034               i ^= e.hashCode();
035         }
036         t = t.getCause();
037      }
038      return i;
039   }
040}