001/*
002 * Copyright 2002-2012 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.web.util;
018
019import javax.servlet.ServletException;
020
021import org.springframework.core.NestedExceptionUtils;
022
023/**
024 * Subclass of {@link ServletException} that properly handles a root cause in terms
025 * of message and stacktrace, just like NestedChecked/RuntimeException does.
026 *
027 * <p>Note that the plain ServletException doesn't expose its root cause at all,
028 * neither in the exception message nor in printed stack traces! While this might
029 * be fixed in later Servlet API variants (which even differ per vendor for the
030 * same API version), it is not reliably available on Servlet 2.4 (the minimum
031 * version required by Spring 3.x), which is why we need to do it ourselves.
032 *
033 * <p>The similarity between this class and the NestedChecked/RuntimeException
034 * class is unavoidable, as this class needs to derive from ServletException.
035 *
036 * @author Juergen Hoeller
037 * @since 1.2.5
038 * @see #getMessage
039 * @see #printStackTrace
040 * @see org.springframework.core.NestedCheckedException
041 * @see org.springframework.core.NestedRuntimeException
042 */
043public class NestedServletException extends ServletException {
044
045        /** Use serialVersionUID from Spring 1.2 for interoperability */
046        private static final long serialVersionUID = -5292377985529381145L;
047
048        static {
049                // Eagerly load the NestedExceptionUtils class to avoid classloader deadlock
050                // issues on OSGi when calling getMessage(). Reported by Don Brown; SPR-5607.
051                NestedExceptionUtils.class.getName();
052        }
053
054
055        /**
056         * Construct a {@code NestedServletException} with the specified detail message.
057         * @param msg the detail message
058         */
059        public NestedServletException(String msg) {
060                super(msg);
061        }
062
063        /**
064         * Construct a {@code NestedServletException} with the specified detail message
065         * and nested exception.
066         * @param msg the detail message
067         * @param cause the nested exception
068         */
069        public NestedServletException(String msg, Throwable cause) {
070                super(msg, cause);
071                // Set JDK 1.4 exception chain cause if not done by ServletException class already
072                // (this differs between Servlet API versions).
073                if (getCause() == null && cause!=null) {
074                        initCause(cause);
075                }
076        }
077
078
079        /**
080         * Return the detail message, including the message from the nested exception
081         * if there is one.
082         */
083        @Override
084        public String getMessage() {
085                return NestedExceptionUtils.buildMessage(super.getMessage(), getCause());
086        }
087
088}