| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.tomcat.dbcp.pool2.impl; |
| |
| import java.io.PrintWriter; |
| import java.text.DateFormat; |
| import java.text.SimpleDateFormat; |
| |
| /** |
| * CallStack strategy that uses the stack trace from a {@link Throwable}. This strategy, while slower than the |
| * SecurityManager implementation, provides call stack method names and other metadata in addition to the call stack |
| * of classes. |
| * |
| * @see Throwable#fillInStackTrace() |
| * @since 2.4.3 |
| */ |
| public class ThrowableCallStack implements CallStack { |
| |
| private final String messageFormat; |
| //@GuardedBy("dateFormat") |
| private final DateFormat dateFormat; |
| |
| private volatile Snapshot snapshot; |
| |
| /** |
| * Create a new instance. |
| * |
| * @param messageFormat message format |
| * @param useTimestamp whether to format the dates in the output message or not |
| */ |
| public ThrowableCallStack(final String messageFormat, final boolean useTimestamp) { |
| this.messageFormat = messageFormat; |
| this.dateFormat = useTimestamp ? new SimpleDateFormat(messageFormat) : null; |
| } |
| |
| @Override |
| public synchronized boolean printStackTrace(final PrintWriter writer) { |
| final Snapshot snapshotRef = this.snapshot; |
| if (snapshotRef == null) { |
| return false; |
| } |
| final String message; |
| if (dateFormat == null) { |
| message = messageFormat; |
| } else { |
| synchronized (dateFormat) { |
| message = dateFormat.format(Long.valueOf(snapshotRef.timestamp)); |
| } |
| } |
| writer.println(message); |
| snapshotRef.printStackTrace(writer); |
| return true; |
| } |
| |
| @Override |
| public void fillInStackTrace() { |
| snapshot = new Snapshot(); |
| } |
| |
| @Override |
| public void clear() { |
| snapshot = null; |
| } |
| |
| /** |
| * A snapshot of a throwable. |
| */ |
| private static class Snapshot extends Throwable { |
| private static final long serialVersionUID = 1L; |
| private final long timestamp = System.currentTimeMillis(); |
| } |
| } |