| /* |
| * 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.logging.log4j.util; |
| |
| import java.util.List; |
| import java.util.Optional; |
| import java.util.Stack; |
| import java.util.function.Function; |
| import java.util.stream.Collectors; |
| import java.util.stream.Stream; |
| |
| /** |
| * <em>Consider this class private.</em> Determines the caller's class. |
| */ |
| public class StackLocator { |
| |
| private final static StackWalker walker = StackWalker.getInstance(StackWalker.Option.RETAIN_CLASS_REFERENCE); |
| |
| private final static StackWalker stackWalker = StackWalker.getInstance(); |
| |
| private final static StackLocator INSTANCE = new StackLocator(); |
| |
| public static StackLocator getInstance() { |
| return INSTANCE; |
| } |
| |
| private StackLocator() { |
| } |
| |
| public Class<?> getCallerClass(final String fqcn) { |
| return getCallerClass(fqcn, ""); |
| } |
| |
| public Class<?> getCallerClass(final String fqcn, final String pkg) { |
| return walker.walk(s -> s.dropWhile(f -> !f.getClassName().equals(fqcn)). |
| dropWhile(f -> f.getClassName().equals(fqcn)).dropWhile(f -> !f.getClassName().startsWith(pkg)). |
| findFirst()).map(StackWalker.StackFrame::getDeclaringClass).orElse(null); |
| } |
| |
| public Class<?> getCallerClass(final Class<?> anchor) { |
| return walker.walk(s -> s.dropWhile(f -> !f.getDeclaringClass().equals(anchor)). |
| dropWhile(f -> f.getDeclaringClass().equals(anchor)).findFirst()). |
| map(StackWalker.StackFrame::getDeclaringClass).orElse(null); |
| } |
| |
| public Class<?> getCallerClass(final int depth) { |
| return walker.walk(s -> s.skip(depth).findFirst()).map(StackWalker.StackFrame::getDeclaringClass).orElse(null); |
| } |
| |
| public Stack<Class<?>> getCurrentStackTrace() { |
| // benchmarks show that using the SecurityManager is much faster than looping through getCallerClass(int) |
| if (PrivateSecurityManagerStackTraceUtil.isEnabled()) { |
| return PrivateSecurityManagerStackTraceUtil.getCurrentStackTrace(); |
| } |
| Stack<Class<?>> stack = new Stack<Class<?>>(); |
| List<Class<?>> classes = walker.walk(s -> s.map(f -> f.getDeclaringClass()).collect(Collectors.toList())); |
| stack.addAll(classes); |
| return stack; |
| } |
| |
| public StackTraceElement calcLocation(final String fqcnOfLogger) { |
| return stackWalker.walk( |
| s -> s.dropWhile(f -> !f.getClassName().equals(fqcnOfLogger)) // drop the top frames until we reach the logger |
| .dropWhile(f -> f.getClassName().equals(fqcnOfLogger)) // drop the logger frames |
| .findFirst()).map(StackWalker.StackFrame::toStackTraceElement).orElse(null); |
| } |
| |
| public StackTraceElement getStackTraceElement(final int depth) { |
| return stackWalker.walk(s -> s.skip(depth).findFirst()) |
| .map(StackWalker.StackFrame::toStackTraceElement).orElse(null); |
| } |
| } |