CheckRuntimeVersion.java

/*
 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */

import java.lang.module.ModuleDescriptor;
import java.lang.module.ModuleFinder;
import java.lang.module.ModuleReference;
import java.util.Arrays;
import java.util.Set;
import java.util.stream.Collectors;

public class CheckRuntimeVersion {
    public static void main(String... args) {
        int version = Integer.parseInt(args[0]);
        if (Runtime.version().major() != version) {
            throw new RuntimeException(version + " != current runtime version "
                + Runtime.version());
        }

        Set<String> expected = Arrays.stream(args, 1, args.length)
                                     .collect(Collectors.toSet());
        Set<String> modules = ModuleFinder.ofSystem().findAll().stream()
            .map(ModuleReference::descriptor)
            .map(ModuleDescriptor::name)
            .collect(Collectors.toSet());

        if (!modules.equals(expected)) {
            throw new RuntimeException("Expected: " + expected +
                " observable modules: " + modules);
        }
    }
}