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Diffstat (limited to 'core/java14/com/vladium/util')
-rw-r--r-- | core/java14/com/vladium/util/IJREVersion.java | 101 |
1 files changed, 101 insertions, 0 deletions
diff --git a/core/java14/com/vladium/util/IJREVersion.java b/core/java14/com/vladium/util/IJREVersion.java new file mode 100644 index 0000000..866c3fe --- /dev/null +++ b/core/java14/com/vladium/util/IJREVersion.java @@ -0,0 +1,101 @@ +/* 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 +// ---------------------------------------------------------------------------- + |