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With inspiration from other libraries
/**
* Logback: the reliable, generic, fast and flexible logging framework.
* Copyright (C) 1999-2015, QOS.ch. All rights reserved.
*
* This program and the accompanying materials are dual-licensed under
* either the terms of the Eclipse Public License v1.0 as published by
* the Eclipse Foundation
*
* or (per the licensee's choosing)
*
* under the terms of the GNU Lesser General Public License version 2.1
* as published by the Free Software Foundation.
*/
package ch.qos.logback.classic.spi;
import java.net.URL;
import java.security.CodeSource;
import java.util.HashMap;
import sun.reflect.Reflection;
// import java.security.AccessControlException; import java.security.AccessController;import java.security.PrivilegedAction;
/**
* Given a classname locate associated PackageInfo (jar name, version name).
*
* @author James Strachan
* @Ceki Gülcü
*/
public class PackagingDataCalculator {
final static StackTraceElementProxy[] STEP_ARRAY_TEMPLATE = new StackTraceElementProxy[0];
HashMap cache = new HashMap();
private static boolean GET_CALLER_CLASS_METHOD_AVAILABLE = false; // private static boolean
// HAS_GET_CLASS_LOADER_PERMISSION = false;
static {
// if either the Reflection class or the getCallerClass method
// are unavailable, then we won't invoke Reflection.getCallerClass()
// This approach ensures that this class will *run* on JDK's lacking
// sun.reflect.Reflection class. However, this class will *not compile*
// on JDKs lacking sun.reflect.Reflection.
try {
Reflection.getCallerClass(2);
GET_CALLER_CLASS_METHOD_AVAILABLE = true;
} catch (NoClassDefFoundError e) {
} catch (NoSuchMethodError e) {
} catch (UnsupportedOperationException e) {
} catch (Throwable e) {
System.err.println("Unexpected exception");
e.printStackTrace();
}
}
public void calculate(IThrowableProxy tp) {
while (tp != null) {
populateFrames(tp.getStackTraceElementProxyArray());
IThrowableProxy[] suppressed = tp.getSuppressed();
if (suppressed != null) {
for (IThrowableProxy current : suppressed) {
populateFrames(current.getStackTraceElementProxyArray());
}
}
tp = tp.getCause();
}
}
void populateFrames(StackTraceElementProxy[] stepArray) {
// in the initial part of this method we populate package information for
// common stack frames
final Throwable t = new Throwable("local stack reference");
final StackTraceElement[] localteSTEArray = t.getStackTrace();
final int commonFrames = STEUtil.findNumberOfCommonFrames(localteSTEArray, stepArray);
final int localFirstCommon = localteSTEArray.length - commonFrames;
final int stepFirstCommon = stepArray.length - commonFrames;
ClassLoader lastExactClassLoader = null;
ClassLoader firsExactClassLoader = null;
int missfireCount = 0;
for (int i = 0; i < commonFrames; i++) {
Class callerClass = null;
if (GET_CALLER_CLASS_METHOD_AVAILABLE) {
callerClass = Reflection.getCallerClass(localFirstCommon + i - missfireCount + 1);
}
StackTraceElementProxy step = stepArray[stepFirstCommon + i];
String stepClassname = step.ste.getClassName();
if (callerClass != null && stepClassname.equals(callerClass.getName())) {
// see also LBCLASSIC-263
lastExactClassLoader = callerClass.getClassLoader();
if (firsExactClassLoader == null) {
firsExactClassLoader = lastExactClassLoader;
}
ClassPackagingData pi = calculateByExactType(callerClass);
step.setClassPackagingData(pi);
} else {
missfireCount++;
ClassPackagingData pi = computeBySTEP(step, lastExactClassLoader);
step.setClassPackagingData(pi);
}
}
populateUncommonFrames(commonFrames, stepArray, firsExactClassLoader);
}
void populateUncommonFrames(int commonFrames, StackTraceElementProxy[] stepArray, ClassLoader firstExactClassLoader) {
int uncommonFrames = stepArray.length - commonFrames;
for (int i = 0; i < uncommonFrames; i++) {
StackTraceElementProxy step = stepArray[i];
ClassPackagingData pi = computeBySTEP(step, firstExactClassLoader);
step.setClassPackagingData(pi);
}
}
private ClassPackagingData calculateByExactType(Class type) {
String className = type.getName();
ClassPackagingData cpd = cache.get(className);
if (cpd != null) {
return cpd;
}
String version = getImplementationVersion(type);
String codeLocation = getCodeLocation(type);
cpd = new ClassPackagingData(codeLocation, version);
cache.put(className, cpd);
return cpd;
}
private ClassPackagingData computeBySTEP(StackTraceElementProxy step, ClassLoader lastExactClassLoader) {
String className = step.ste.getClassName();
ClassPackagingData cpd = cache.get(className);
if (cpd != null) {
return cpd;
}
Class type = bestEffortLoadClass(lastExactClassLoader, className);
String version = getImplementationVersion(type);
String codeLocation = getCodeLocation(type);
cpd = new ClassPackagingData(codeLocation, version, false);
cache.put(className, cpd);
return cpd;
}
String getImplementationVersion(Class type) {
if (type == null) {
return "na";
}
Package aPackage = type.getPackage();
if (aPackage != null) {
String v = aPackage.getImplementationVersion();
if (v == null) {
return "na";
} else {
return v;
}
}
return "na";
}
String getCodeLocation(Class type) {
try {
if (type != null) {
// file:/C:/java/maven-2.0.8/repo/com/icegreen/greenmail/1.3/greenmail-1.3.jar
CodeSource codeSource = type.getProtectionDomain().getCodeSource();
if (codeSource != null) {
URL resource = codeSource.getLocation();
if (resource != null) {
String locationStr = resource.toString();
// now lets remove all but the file name
String result = getCodeLocation(locationStr, '/');
if (result != null) {
return result;
}
return getCodeLocation(locationStr, '\\');
}
}
}
} catch (Exception e) {
// ignore
}
return "na";
}
private String getCodeLocation(String locationStr, char separator) {
int idx = locationStr.lastIndexOf(separator);
if (isFolder(idx, locationStr)) {
idx = locationStr.lastIndexOf(separator, idx - 1);
return locationStr.substring(idx + 1);
} else if (idx > 0) {
return locationStr.substring(idx + 1);
}
return null;
}
private boolean isFolder(int idx, String text) {
return (idx != -1 && idx + 1 == text.length());
}
private Class loadClass(ClassLoader cl, String className) {
if (cl == null) {
return null;
}
try {
return cl.loadClass(className);
} catch (ClassNotFoundException e1) {
return null;
} catch (NoClassDefFoundError e1) {
return null;
} catch (Exception e) {
e.printStackTrace(); // this is unexpected
return null;
}
}
/**
* @param lastGuaranteedClassLoader may be null
* @param className
* @return
*/
private Class bestEffortLoadClass(ClassLoader lastGuaranteedClassLoader, String className) {
Class result = loadClass(lastGuaranteedClassLoader, className);
if (result != null) {
return result;
}
ClassLoader tccl = Thread.currentThread().getContextClassLoader();
if (tccl != lastGuaranteedClassLoader) {
result = loadClass(tccl, className);
}
if (result != null) {
return result;
}
try {
return Class.forName(className);
} catch (ClassNotFoundException e1) {
return null;
} catch (NoClassDefFoundError e1) {
return null;
} catch (Exception e) {
e.printStackTrace(); // this is unexpected
return null;
}
}
}