001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.commons.scxml.env; 018 019 import java.util.Iterator; 020 import java.util.LinkedList; 021 022 import org.apache.commons.scxml.model.Transition; 023 import org.apache.commons.scxml.model.TransitionTarget; 024 025 /** 026 * Helper methods for Commons SCXML logging. 027 * 028 */ 029 public final class LogUtils { 030 031 /** 032 * Create a human readable log view of this transition. 033 * 034 * @param from The source TransitionTarget 035 * @param to The destination TransitionTarget 036 * @param transition The Transition that is taken 037 * @return String The human readable log entry 038 */ 039 public static String transToString(final TransitionTarget from, 040 final TransitionTarget to, final Transition transition) { 041 StringBuffer buf = new StringBuffer("transition ("); 042 buf.append("event = ").append(transition.getEvent()); 043 buf.append(", cond = ").append(transition.getCond()); 044 buf.append(", from = ").append(getTTPath(from)); 045 buf.append(", to = ").append(getTTPath(to)); 046 buf.append(')'); 047 return buf.toString(); 048 } 049 050 /** 051 * Write out this TransitionTarget location in a XPath style format. 052 * 053 * @param tt The TransitionTarget whose "path" is to needed 054 * @return String The XPath style location of the TransitionTarget within 055 * the SCXML document 056 */ 057 public static String getTTPath(final TransitionTarget tt) { 058 TransitionTarget parent = tt.getParent(); 059 if (parent == null) { 060 return "/" + tt.getId(); 061 } else { 062 LinkedList pathElements = new LinkedList(); 063 pathElements.addFirst(tt); 064 while (parent != null) { 065 pathElements.addFirst(parent); 066 parent = parent.getParent(); 067 } 068 StringBuffer names = new StringBuffer(); 069 for (Iterator i = pathElements.iterator(); i.hasNext();) { 070 TransitionTarget pathElement = (TransitionTarget) i.next(); 071 names.append('/').append(pathElement.getId()); 072 } 073 return names.toString(); 074 } 075 } 076 077 /** 078 * Discourage instantiation since this is a utility class. 079 */ 080 private LogUtils() { 081 super(); 082 } 083 084 }