com.diozero.util.FileUtil Maven / Gradle / Ivy
package com.diozero.util;
/*
* #%L
* Organisation: mattjlewis
* Project: Device I/O Zero - Core
* Filename: FileUtil.java
*
* This file is part of the diozero project. More information about this project
* can be found at http://www.diozero.com/
* %%
* Copyright (C) 2016 - 2017 mattjlewis
* %%
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
* #L%
*/
import java.io.FileDescriptor;
import java.lang.reflect.Field;
import org.pmw.tinylog.Logger;
public class FileUtil {
private static boolean initialised;
private static Field fdField;
public static synchronized int getNativeFileDescriptor(FileDescriptor fd) {
if (! initialised) {
try {
fdField = FileDescriptor.class.getDeclaredField("fd");
fdField.setAccessible(true);
initialised = true;
} catch (NoSuchFieldException | SecurityException e) {
Logger.error(e, "Error: {}", e);
throw new RuntimeIOException("Error getting native file descriptor declared field: " + e, e);
}
}
try {
return ((Integer) fdField.get(fd)).intValue();
} catch (IllegalArgumentException | IllegalAccessException e) {
Logger.error(e, "Error: {}", e);
throw new RuntimeIOException("Error accessing private fd attribute: " + e, e);
}
}
}