/**
* 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);
}
}