com.b2international.commons.SystemUtils.java Source code

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Here is the source code for com.b2international.commons.SystemUtils.java

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/*
 * Copyright 2011-2015 B2i Healthcare Pte Ltd, http://b2i.sg
 * 
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.b2international.commons;

import static com.google.common.base.Suppliers.memoize;

import com.google.common.base.Preconditions;
import com.google.common.base.Strings;
import com.google.common.base.Supplier;

/**
 * Utility class for {@link System} class.
 */
public abstract class SystemUtils {

    public static final String OS_NAME = "os.name";

    private static final String LINE_SEPARATOR = "line.separator";
    private static final String MAC = "Mac";
    private static final String WINDOWS = "Windows";
    private static final long SLEEP_INTERVAL = 100;

    private static final Supplier<String> LINE_SEPARATOR_SUPPLIER = memoize(new Supplier<String>() {
        @Override
        public String get() {
            return getProperty(LINE_SEPARATOR);
        }
    });

    /**
     * Gets the system property indicated by the specified key. Could be {@code null}.
     * @param key the key of the property.
     * @return the system property.
     */
    public static String getProperty(final String key) {
        return System.getProperty(Preconditions.checkNotNull(key, "Property key argument cannot be null."));
    }

    /**Returns with the platform dependent line separator as a string.*/
    public static String getLineSeparator() {
        return LINE_SEPARATOR_SUPPLIER.get();
    }

    /**
     * Requests a hard garbage collection from the virtual machine.
     * <br>This method is identical as {@code #performHardGC(2)};
     * @see #performHardGC(int)
     */
    public static void performHardGC() {
        performHardGC(2);
    }

    /**
     * Requests a hard GC from the VM.
     * @param count the number of GC request.
     */
    public static void performHardGC(int count) {

        for (int i = 0; i < count; i++) {

            try {

                System.gc();
                Thread.sleep(SLEEP_INTERVAL);

                System.runFinalization();
                Thread.sleep(SLEEP_INTERVAL);

            } catch (final InterruptedException e) {

                Thread.currentThread().interrupt();

            }

        }

    }

    /**
     * Returns {@code true} if the underlying OS is Mac.
     */
    public static boolean isMac() {
        return getOsSafe().indexOf(MAC) != -1;
    }

    /**
     * Returns {@code true} if the underlying OS is Windows.
     */
    public static boolean isWindows() {
        return getOsSafe().indexOf(WINDOWS) != -1;
    }

    private static String getOsSafe() {
        return Strings.nullToEmpty(getProperty(OS_NAME));
    }

    private SystemUtils() {
        /*suppress instantiation*/ }

}