jgit/org.eclipse.jgit/src/org/eclipse/jgit/util/FS_POSIX_Java6.java

/*
 * Copyright (C) 2007, Robin Rosenberg <me@lathund.dewire.com>
 * Copyright (C) 2007, Robin Rosenberg <robin.rosenberg@dewire.com>
 * Copyright (C) 2008, Shawn O. Pearce <spearce@spearce.org>
 * and other copyright owners as documented in the project's IP log.
 *
 * This program and the accompanying materials are made available
 * under the terms of the Eclipse Distribution License v1.0 which
 * accompanies this distribution, is reproduced below, and is
 * available at http://www.eclipse.org/org/documents/edl-v10.php
 *
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or
 * without modification, are permitted provided that the following
 * conditions are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above
 *   copyright notice, this list of conditions and the following
 *   disclaimer in the documentation and/or other materials provided
 *   with the distribution.
 *
 * - Neither the name of the Eclipse Foundation, Inc. nor the
 *   names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package org.eclipse.jgit.util;

import java.io.File;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;


/**
 * FS implementation for POSIX systems using Java6
 *
 * @since 3.0
 */
public class FS_POSIX_Java6 extends FS_POSIX {
	private static final Method canExecute;

	private static final Method setExecute;

	static {
		canExecute = needMethod(File.class, "canExecute"); //$NON-NLS-1$
		setExecute = needMethod(File.class, "setExecutable", Boolean.TYPE); //$NON-NLS-1$
	}

	/**
	 * @return true if Java has the ability to set and get the executable flag
	 *         on files
	 */
	public static boolean hasExecute() {
		return canExecute != null && setExecute != null;
	}

	private static Method needMethod(final Class<?> on, final String name,
			final Class<?>... args) {
		try {
			return on.getMethod(name, args);
		} catch (SecurityException e) {
			return null;
		} catch (NoSuchMethodException e) {
			return null;
		}
	}

	/**
	 * Constructor
	 */
	public FS_POSIX_Java6() {
		super();
	}

	/**
	 * Constructor
	 *
	 * @param src
	 *            instance whose attributes to copy
	 */
	public FS_POSIX_Java6(FS src) {
		super(src);
	}

	@Override
	public FS newInstance() {
		return new FS_POSIX_Java6(this);
	}

	public boolean supportsExecute() {
		return true;
	}

	public boolean canExecute(final File f) {
		try {
			final Object r = canExecute.invoke(f, (Object[]) null);
			return ((Boolean) r).booleanValue();
		} catch (IllegalArgumentException e) {
			throw new Error(e);
		} catch (IllegalAccessException e) {
			throw new Error(e);
		} catch (InvocationTargetException e) {
			throw new Error(e);
		}
	}

	public boolean setExecute(final File f, final boolean canExec) {
		try {
			final Object r;
			r = setExecute.invoke(f, new Object[] { Boolean.valueOf(canExec) });
			return ((Boolean) r).booleanValue();
		} catch (IllegalArgumentException e) {
			throw new Error(e);
		} catch (IllegalAccessException e) {
			throw new Error(e);
		} catch (InvocationTargetException e) {
			throw new Error(e);
		}
	}

	@Override
	public boolean retryFailedLockFileCommit() {
		return false;
	}
}