Logback: the reliable, generic, fast and flexible logging framework.
Copyright (C) 1999-2015, QOS.ch. All rights reserved.
This program and the accompanying materials are dual-licensed under
either the terms of the Eclipse Public License v1.0 as published by
the Eclipse Foundation
  or (per the licensee's choosing)
under the terms of the GNU Lesser General Public License version 2.1
as published by the Free Software Foundation.
/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.core.util;

import java.util.ArrayList;
import java.util.List;

Author:
Ceki Gülcü/**
 * @author Ceki Gülcü
 */
public class EnvUtil {

    static private boolean isJDK_N_OrHigher(int n) {
        List<String> versionList = new ArrayList<String>();
        // this code should work at least until JDK 10 (assuming n parameter is
        // always 6 or more)
        for (int i = 0; i < 5; i++) {
            versionList.add("1." + (n + i));
        }

        String javaVersion = System.getProperty("java.version");
        if (javaVersion == null) {
            return false;
        }
        for (String v : versionList) {
            if (javaVersion.startsWith(v))
                return true;
        }
        return false;
    }

    static public boolean isJDK5() {
        return isJDK_N_OrHigher(5);
    }

    static public boolean isJDK6OrHigher() {
        return isJDK_N_OrHigher(6);
    }

    static public boolean isJDK7OrHigher() {
        return isJDK_N_OrHigher(7);
    }

    static public boolean isJaninoAvailable() {
        ClassLoader classLoader = EnvUtil.class.getClassLoader();
        try {
            Class<?> bindingClass = classLoader.loadClass("org.codehaus.janino.ScriptEvaluator");
            return (bindingClass != null);
        } catch (ClassNotFoundException e) {
            return false;
        }
    }

    public static boolean isWindows() {
        String os = System.getProperty("os.name");
        return os.startsWith("Windows");
    }

}