1 /* 2 * Copyright (c) 1998, 1999, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package com.sun.jdi.event; 27 28 import com.sun.jdi.*; 29 30 /** 31 * Notification of an exception in the target VM. When an exception 32 * is thrown which satisfies a currently enabled 33 * {@link com.sun.jdi.request.ExceptionRequest exception request}, 34 * an {@link EventSet event set} 35 * containing an instance of this class will be added 36 * to the VM's event queue. 37 * If the exception is thrown from a non-native method, 38 * the exception event is generated at the location where the 39 * exception is thrown. 40 * If the exception is thrown from a native method, the exception event 41 * is generated at the first non-native location reached after the exception 42 * is thrown. 43 * 44 * @author Robert Field 45 * @since 1.3 46 */ 47 public interface ExceptionEvent extends LocatableEvent { 48 49 /** 50 * Gets the thrown exception object. The exception object is 51 * an instance of {@link java.lang.Throwable} or a subclass in the 52 * target VM. 53 * 54 * @return an {@link ObjectReference} which mirrors the thrown object in 55 * the target VM. 56 */ 57 public ObjectReference exception(); 58 59 /** 60 * Gets the location where the exception will be caught. An exception 61 * is considered to be caught if, at the point of the throw, the 62 * current location is dynamically enclosed in a try statement that 63 * handles the exception. (See the JVM specification for details). 64 * If there is such a try statement, the catch location is the 65 * first code index of the appropriate catch clause. 66 * <p> 67 * If there are native methods in the call stack at the time of the 68 * exception, there are important restrictions to note about the 69 * returned catch location. In such cases, 70 * it is not possible to predict whether an exception will be handled 71 * by some native method on the call stack. 72 * Thus, it is possible that exceptions considered uncaught 73 * here will, in fact, be handled by a native method and not cause 74 * termination of the target VM. Furthermore, it cannot be assumed that the 75 * catch location returned here will ever be reached by the throwing 76 * thread. If there is 77 * a native frame between the current location and the catch location, 78 * the exception might be handled and cleared in that native method 79 * instead. 80 * <p> 81 * Note that the compiler can generate try-catch blocks in some cases 82 * where they are not explicit in the source code; for example, 83 * the code generated for <code>synchronized</code> and 84 * <code>finally</code> blocks can contain implicit try-catch blocks. 85 * If such an implicitly generated try-catch is 86 * present on the call stack at the time of the throw, the exception 87 * will be considered caught even though it appears to be uncaught from 88 * examination of the source code. 89 * 90 * @return the {@link Location} where the exception will be caught or null if 91 * the exception is uncaught. 92 */ 93 public Location catchLocation(); 94 }