Java7Checker.java

/*
 * Copyright Red Hat Inc. and/or its affiliates and other contributors
 * as indicated by the authors tag. All rights reserved.
 *
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU General Public License version 2.
 * 
 * This particular file is subject to the "Classpath" exception as provided in the 
 * LICENSE file that accompanied this code.
 * 
 * This program is distributed in the hope that it will be useful, but WITHOUT A
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 * PARTICULAR PURPOSE.  See the GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License,
 * along with this distribution; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA  02110-1301, USA.
 */

package com.redhat.ceylon.ant;

public class Java7Checker {

    public static void check() {
        String version = System.getProperty("java.version");
        String[] elems = (version != null) ? version.split("\\.|_|-") : null;
        if (version != null && !version.isEmpty() && elems != null && elems.length >= 3) {
            try {
                int major = Integer.parseInt(elems[0]);
                int minor = Integer.parseInt(elems[1]);
                int release = Integer.parseInt(elems[2]);
                if (major != 1 || minor < 7) {
                    System.err.println("Your Java version is not supported: " + version);
                    System.err.println("Ceylon needs Java 7 or newer. Please install it from http://www.java.com");
                    System.err.println("Aborting.");
                    System.exit(1);
                }
                return;
            } catch (NumberFormatException ex) {}
        }
        System.err.println("Unable to determine Java version (java.version property missing, empty or has unexpected format: '" + version +"'). Aborting.");
        System.exit(1);
    }
    
}