| /* |
| * Copyright (C) 2003-2009 JNode.org |
| * 2009,2010 Matthias Treydte <mt@waldheinz.de> |
| * |
| * This library is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU Lesser General Public License as published |
| * by the Free Software Foundation; either version 2.1 of the License, or |
| * (at your option) any later version. |
| * |
| * This library 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 Lesser General Public |
| * License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public License |
| * along with this library; If not, write to the Free Software Foundation, Inc., |
| * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. |
| */ |
| |
| package de.waldheinz.fs; |
| |
| /** |
| * A base class that helps to implement the {@code FsObject} interface. |
| * |
| * @author Ewout Prangsma <epr at jnode.org> |
| * @author Matthias Treydte <waldheinz at gmail.com> |
| * @since 0.6 |
| */ |
| public class AbstractFsObject implements FsObject { |
| |
| /** |
| * Holds the read-only state of this object. |
| */ |
| private final boolean readOnly; |
| |
| /** |
| * Remembers if this object still valid. |
| */ |
| private boolean valid; |
| |
| /** |
| * Creates a new instance of {@code AbstractFsObject} which will be valid |
| * and have the specified read-only state. |
| * |
| * @param readOnly if the new object will be read-only |
| */ |
| protected AbstractFsObject(boolean readOnly) { |
| this.valid = true; |
| this.readOnly = readOnly; |
| } |
| |
| /** |
| * {@inheritDoc} |
| * |
| * @return {@inheritDoc} |
| * @see #checkValid() |
| * @see #invalidate() |
| */ |
| @Override |
| public final boolean isValid() { |
| return this.valid; |
| } |
| |
| /** |
| * Marks this object as invalid. |
| * |
| * @see #isValid() |
| * @see #checkValid() |
| */ |
| protected final void invalidate() { |
| this.valid = false; |
| } |
| |
| /** |
| * Convience method to check if this object is still valid and throw an |
| * {@code IllegalStateException} if it is not. |
| * |
| * @throws IllegalStateException if this object was invalidated |
| * @since 0.6 |
| * @see #isValid() |
| * @see #invalidate() |
| */ |
| protected final void checkValid() throws IllegalStateException { |
| if (!isValid()) throw new IllegalStateException( |
| this + " is not valid"); |
| } |
| |
| /** |
| * Convience method to check if this object is writable. An object is |
| * writable if it is both, valid and not read-only. |
| * |
| * @throws IllegalStateException if this object was invalidated |
| * @throws ReadOnlyException if this object was created with the read-only |
| * flag set |
| * @since 0.6 |
| */ |
| protected final void checkWritable() |
| throws IllegalStateException, ReadOnlyException { |
| |
| checkValid(); |
| |
| if (isReadOnly()) { |
| throw new ReadOnlyException(); |
| } |
| } |
| |
| @Override |
| public final boolean isReadOnly() { |
| return this.readOnly; |
| } |
| |
| } |