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/* Copyright (C) 2003 Vladimir Roubtsov. All rights reserved.
*
* This program and the accompanying materials are made available under
* the terms of the Common Public License v1.0 which accompanies this distribution,
* and is available at http://www.eclipse.org/legal/cpl-v10.html
*
* $Id: IJREVersion.java,v 1.1.1.1.2.1 2004/07/10 03:34:52 vlad_r Exp $
*/
package com.vladium.util;
// ----------------------------------------------------------------------------
/**
* A constant collection to detect the current JRE version. Note that this code
* is more sophisticated then a mere check of "java.version" or "java.class.version"
* and similar system properties because some JVMs allow overriding those
* by the user (e.g., from the command line). This implementation relies on
* the core classes only and tries to minimize the number of security-sensitive
* methods it uses.<P>
*
* This interface is supported in Java 1.1+ and should be compiled with class
* version stamp 45.3 (-target 1.1).
*
* @author Vlad Roubtsov, (C) 2003
*/
public
interface IJREVersion
{
// public: ................................................................
/** 'true' iff the current runtime version is 1.2 or later */
boolean JRE_1_2_PLUS = _JREVersion._JRE_1_2_PLUS; // static final but not inlinable
/** 'true' iff the current runtime version is 1.3 or later */
boolean JRE_1_3_PLUS = _JREVersion._JRE_1_3_PLUS; // static final but not inlinable
/** 'true' iff the current runtime version is 1.4 or later */
boolean JRE_1_4_PLUS = _JREVersion._JRE_1_4_PLUS; // static final but not inlinable
// supporting Java 1.5 is trivial...
boolean JRE_SUN_SIGNAL_COMPATIBLE = _JREVersion._JRE_SUN_SIGNAL_COMPATIBLE;
/*
* Use a dummy nested class to fake a static initializer for the outer
* interface (I want IJREVersion as an interface and not a class so that
* all JRE_XXX constants could be imported via "implements").
*/
abstract class _JREVersion
{
static final boolean _JRE_1_2_PLUS; // set in <clinit>
static final boolean _JRE_1_3_PLUS; // set in <clinit>
static final boolean _JRE_1_4_PLUS; // set in <clinit>
static final boolean _JRE_SUN_SIGNAL_COMPATIBLE; // set in <clinit>
private _JREVersion () {} // prevent subclassing
static
{
_JRE_1_2_PLUS = ((SecurityManager.class.getModifiers () & 0x0400) == 0);
boolean temp = false;
if (_JRE_1_2_PLUS)
{
try
{
StrictMath.abs (1.0);
temp = true;
}
catch (Error ignore) {}
}
_JRE_1_3_PLUS = temp;
if (temp)
{
temp = false;
try
{
" ".subSequence (0, 0);
temp = true;
}
catch (NoSuchMethodError ignore) {}
}
_JRE_1_4_PLUS = temp;
temp = false;
try
{
Class.forName ("sun.misc.Signal");
Class.forName ("sun.misc.SignalHandler");
temp = true;
}
catch (Throwable ignore) {}
_JRE_SUN_SIGNAL_COMPATIBLE = temp;
}
} // end of nested class
} // end of interface
// ----------------------------------------------------------------------------
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