1 /*
   2  * reserved comment block
   3  * DO NOT REMOVE OR ALTER!
   4  */
   5 /*
   6  * Licensed to the Apache Software Foundation (ASF) under one or more
   7  * contributor license agreements.  See the NOTICE file distributed with
   8  * this work for additional information regarding copyright ownership.
   9  * The ASF licenses this file to You under the Apache License, Version 2.0
  10  * (the "License"); you may not use this file except in compliance with
  11  * the License.  You may obtain a copy of the License at
  12  *
  13  *      http://www.apache.org/licenses/LICENSE-2.0
  14  *
  15  * Unless required by applicable law or agreed to in writing, software
  16  * distributed under the License is distributed on an "AS IS" BASIS,
  17  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  18  * See the License for the specific language governing permissions and
  19  * limitations under the License.
  20  */
  21 
  22 package com.sun.org.apache.bcel.internal.generic;
  23 
  24 /**
  25  * Thrown by InstructionList.remove() when one or multiple disposed instructions
  26  * are still being referenced by an InstructionTargeter object. I.e. the
  27  * InstructionTargeter has to be notified that (one of) the InstructionHandle it
  28  * is referencing is being removed from the InstructionList and thus not valid anymore.
  29  *
  30  * <p>Making this an exception instead of a return value forces the user to handle
  31  * these case explicitely in a try { ... } catch. The following code illustrates
  32  * how this may be done:</p>
  33  *
  34  * <PRE>
  35  *     ...
  36  *     try {
  37  *         il.delete(start_ih, end_ih);
  38  *     } catch(TargetLostException e) {
  39  *         for (InstructionHandle target : e.getTargets()) {
  40  *             for (InstructionTargeter targeter : target.getTargeters()) {
  41  *                 targeter.updateTarget(target, new_target);
  42  *             }
  43  *         }
  44  *     }
  45  * </PRE>
  46  *
  47  * @see InstructionHandle
  48  * @see InstructionList
  49  * @see InstructionTargeter
  50  * @version $Id$
  51  */
  52 public final class TargetLostException extends Exception {
  53 
  54     private static final long serialVersionUID = -6857272667645328384L;
  55     private final InstructionHandle[] targets;
  56 
  57 
  58     TargetLostException(final InstructionHandle[] t, final String mesg) {
  59         super(mesg);
  60         targets = t;
  61     }
  62 
  63 
  64     /**
  65      * @return list of instructions still being targeted.
  66      */
  67     public InstructionHandle[] getTargets() {
  68         return targets;
  69     }
  70 }