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 */ 018package org.apache.bcel.generic; 019 020/** 021 * Thrown by InstructionList.remove() when one or multiple disposed instructions 022 * are still being referenced by an InstructionTargeter object. I.e. the 023 * InstructionTargeter has to be notified that (one of) the InstructionHandle it 024 * is referencing is being removed from the InstructionList and thus not valid anymore. 025 * 026 * <p>Making this an exception instead of a return value forces the user to handle 027 * these case explicitely in a try { ... } catch. The following code illustrates 028 * how this may be done:</p> 029 * 030 * <PRE> 031 * ... 032 * try { 033 * il.delete(start_ih, end_ih); 034 * } catch(TargetLostException e) { 035 * for (InstructionHandle target : e.getTargets()) { 036 * for (InstructionTargeter targeter : target.getTargeters()) { 037 * targeter.updateTarget(target, new_target); 038 * } 039 * } 040 * } 041 * </PRE> 042 * 043 * @see InstructionHandle 044 * @see InstructionList 045 * @see InstructionTargeter 046 */ 047public final class TargetLostException extends Exception { 048 049 private static final long serialVersionUID = -6857272667645328384L; 050 private final InstructionHandle[] targets; 051 052 053 TargetLostException(final InstructionHandle[] t, final String mesg) { 054 super(mesg); 055 targets = t; 056 } 057 058 059 /** 060 * @return list of instructions still being targeted. 061 */ 062 public InstructionHandle[] getTargets() { 063 return targets; 064 } 065}