/* 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.

* * 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 static final boolean _JRE_1_3_PLUS; // set in static final boolean _JRE_1_4_PLUS; // set in static final boolean _JRE_SUN_SIGNAL_COMPATIBLE; // set in 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; _JRE_SUN_SIGNAL_COMPATIBLE = temp; } } // end of nested class } // end of interface // ----------------------------------------------------------------------------