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Java example source code file (StackTraceElements.java)
The StackTraceElements.java Java example source code/** * Copyright (C) 2006 Google Inc. * * Licensed 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 com.google.inject.internal.util; import com.google.common.cache.CacheBuilder; import com.google.common.cache.CacheLoader; import com.google.common.cache.LoadingCache; import java.io.IOException; import java.lang.reflect.Constructor; import java.lang.reflect.Member; import java.util.concurrent.ConcurrentHashMap; import java.util.concurrent.ConcurrentMap; /** * Creates stack trace elements for members. * * @author crazybob@google.com (Bob Lee) */ public class StackTraceElements { private static final StackTraceElement[] EMPTY_STACK_TRACE = new StackTraceElement[0]; private static final InMemoryStackTraceElement[] EMPTY_INMEMORY_STACK_TRACE = new InMemoryStackTraceElement[0]; /*if[AOP]*/ static final LoadingCache<Class>, LineNumbers> lineNumbersCache = CacheBuilder.newBuilder().weakKeys().softValues().build( new CacheLoader<Class>, LineNumbers>() { public LineNumbers load(Class<?> key) { try { return new LineNumbers(key); } catch (IOException e) { throw new RuntimeException(e); } } }); /*end[AOP]*/ private static final ConcurrentMap<InMemoryStackTraceElement, InMemoryStackTraceElement> elementCache = new ConcurrentHashMap<InMemoryStackTraceElement, InMemoryStackTraceElement>(); private static final ConcurrentMap<String, String> stringCache = new ConcurrentHashMap<String, String>(); private static final String UNKNOWN_SOURCE = "Unknown Source"; public static Object forMember(Member member) { if (member == null) { return SourceProvider.UNKNOWN_SOURCE; } Class declaringClass = member.getDeclaringClass(); /*if[AOP]*/ LineNumbers lineNumbers = lineNumbersCache.getUnchecked(declaringClass); String fileName = lineNumbers.getSource(); Integer lineNumberOrNull = lineNumbers.getLineNumber(member); int lineNumber = lineNumberOrNull == null ? lineNumbers.getFirstLine() : lineNumberOrNull; /*end[AOP]*/ /*if[NO_AOP] String fileName = null; int lineNumber = -1; end[NO_AOP]*/ Class<? extends Member> memberType = Classes.memberType(member); String memberName = memberType == Constructor.class ? "<init>" : member.getName(); return new StackTraceElement(declaringClass.getName(), memberName, fileName, lineNumber); } public static Object forType(Class<?> implementation) { /*if[AOP]*/ LineNumbers lineNumbers = lineNumbersCache.getUnchecked(implementation); int lineNumber = lineNumbers.getFirstLine(); String fileName = lineNumbers.getSource(); /*end[AOP]*/ /*if[NO_AOP] String fileName = null; int lineNumber = -1; end[NO_AOP]*/ return new StackTraceElement(implementation.getName(), "class", fileName, lineNumber); } /** * Clears the internal cache for {@link StackTraceElement StackTraceElements}. */ public static void clearCache() { elementCache.clear(); stringCache.clear(); } /** * Returns encoded in-memory version of {@link StackTraceElement StackTraceElements}. */ public static InMemoryStackTraceElement[] convertToInMemoryStackTraceElement( StackTraceElement[] stackTraceElements) { if (stackTraceElements.length == 0) { return EMPTY_INMEMORY_STACK_TRACE; } InMemoryStackTraceElement[] inMemoryStackTraceElements = new InMemoryStackTraceElement[stackTraceElements.length]; for (int i = 0; i < stackTraceElements.length; i++) { inMemoryStackTraceElements[i] = weakIntern(new InMemoryStackTraceElement(stackTraceElements[i])); } return inMemoryStackTraceElements; } /** * Decodes in-memory stack trace elements to regular {@link StackTraceElement StackTraceElements}. */ public static StackTraceElement[] convertToStackTraceElement( InMemoryStackTraceElement[] inMemoryStackTraceElements) { if (inMemoryStackTraceElements.length == 0) { return EMPTY_STACK_TRACE; } StackTraceElement[] stackTraceElements = new StackTraceElement[inMemoryStackTraceElements.length]; for (int i = 0; i < inMemoryStackTraceElements.length; i++) { String declaringClass = inMemoryStackTraceElements[i].getClassName(); String methodName = inMemoryStackTraceElements[i].getMethodName(); int lineNumber = inMemoryStackTraceElements[i].getLineNumber(); stackTraceElements[i] = new StackTraceElement(declaringClass, methodName, UNKNOWN_SOURCE, lineNumber); } return stackTraceElements; } private static InMemoryStackTraceElement weakIntern( InMemoryStackTraceElement inMemoryStackTraceElement) { InMemoryStackTraceElement cached = elementCache.get(inMemoryStackTraceElement); if (cached != null) { return cached; } inMemoryStackTraceElement = new InMemoryStackTraceElement( weakIntern(inMemoryStackTraceElement.getClassName()), weakIntern(inMemoryStackTraceElement.getMethodName()), inMemoryStackTraceElement.getLineNumber()); elementCache.put(inMemoryStackTraceElement, inMemoryStackTraceElement); return inMemoryStackTraceElement; } private static String weakIntern(String s) { String cached = stringCache.get(s); if (cached != null) { return cached; } stringCache.put(s, s); return s; } /** * In-Memory version of {@link StackTraceElement} that does not store the file name. */ public static class InMemoryStackTraceElement { private String declaringClass; private String methodName; private int lineNumber; InMemoryStackTraceElement(StackTraceElement ste) { this(ste.getClassName(), ste.getMethodName(), ste.getLineNumber()); } InMemoryStackTraceElement(String declaringClass, String methodName, int lineNumber) { this.declaringClass = declaringClass; this.methodName = methodName; this.lineNumber = lineNumber; } String getClassName() { return declaringClass; } String getMethodName() { return methodName; } int getLineNumber() { return lineNumber; } @Override public boolean equals(Object obj) { if (obj == this) { return true; } if (!(obj instanceof InMemoryStackTraceElement)) { return false; } InMemoryStackTraceElement e = (InMemoryStackTraceElement) obj; return e.declaringClass.equals(declaringClass) && e.lineNumber == lineNumber && methodName.equals(e.methodName); } @Override public int hashCode() { int result = 31 * declaringClass.hashCode() + methodName.hashCode(); result = 31 * result + lineNumber; return result; } @Override public String toString() { return declaringClass + "." + methodName + "(" + lineNumber + ")"; } } } Other Java examples (source code examples)Here is a short list of links related to this Java StackTraceElements.java source code file: |
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