org.slf4j.helpers.Util Maven / Gradle / Ivy
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/**
* Copyright (c) 2004-2011 QOS.ch
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
*/
package org.slf4j.helpers;
/**
* An internal utility class.
*
* @author Alexander Dorokhine
* @author Ceki Gülcü
*/
public final class Util {
private Util() {
}
public static String safeGetSystemProperty(String key) {
if (key == null)
throw new IllegalArgumentException("null input");
String result = null;
try {
result = System.getProperty(key);
} catch (java.lang.SecurityException sm) {
; // ignore
}
return result;
}
public static boolean safeGetBooleanSystemProperty(String key) {
String value = safeGetSystemProperty(key);
if (value == null)
return false;
else
return value.equalsIgnoreCase("true");
}
/**
* In order to call {@link SecurityManager#getClassContext()}, which is a
* protected method, we add this wrapper which allows the method to be visible
* inside this package.
*/
private static final class ClassContextSecurityManager extends SecurityManager {
protected Class[] getClassContext() {
return super.getClassContext();
}
}
private static ClassContextSecurityManager SECURITY_MANAGER;
private static boolean SECURITY_MANAGER_CREATION_ALREADY_ATTEMPTED = false;
private static ClassContextSecurityManager getSecurityManager() {
if (SECURITY_MANAGER != null)
return SECURITY_MANAGER;
else if (SECURITY_MANAGER_CREATION_ALREADY_ATTEMPTED)
return null;
else {
SECURITY_MANAGER = safeCreateSecurityManager();
SECURITY_MANAGER_CREATION_ALREADY_ATTEMPTED = true;
return SECURITY_MANAGER;
}
}
private static ClassContextSecurityManager safeCreateSecurityManager() {
try {
return new ClassContextSecurityManager();
} catch (java.lang.SecurityException sm) {
return null;
}
}
/**
* Returns the name of the class which called the invoking method.
*
* @return the name of the class which called the invoking method.
*/
public static Class getCallingClass() {
ClassContextSecurityManager securityManager = getSecurityManager();
if (securityManager == null)
return null;
Class[] trace = securityManager.getClassContext();
String thisClassName = Util.class.getName();
// Advance until Util is found
int i;
for (i = 0; i < trace.length; i++) {
if (thisClassName.equals(trace[i].getName()))
break;
}
// trace[i] = Util; trace[i+1] = caller; trace[i+2] = caller's caller
if (i >= trace.length || i + 2 >= trace.length) {
throw new IllegalStateException("Failed to find org.slf4j.helpers.Util or its caller in the stack; " + "this should not happen");
}
return trace[i + 2];
}
static final public void report(String msg, Throwable t) {
System.err.println(msg);
System.err.println("Reported exception:");
t.printStackTrace();
}
static final public void report(String msg) {
System.err.println("SLF4J: " + msg);
}
}