| /* |
| * Copyright (c) 2007, 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.nio.file; |
| |
| import java.nio.file.attribute.*; |
| import java.io.IOException; |
| |
| /** |
| * Storage for files. A {@code FileStore} represents a storage pool, device, |
| * partition, volume, concrete file system or other implementation specific means |
| * of file storage. The {@code FileStore} for where a file is stored is obtained |
| * by invoking the {@link Files#getFileStore getFileStore} method, or all file |
| * stores can be enumerated by invoking the {@link FileSystem#getFileStores |
| * getFileStores} method. |
| * |
| * <p> In addition to the methods defined by this class, a file store may support |
| * one or more {@link FileStoreAttributeView FileStoreAttributeView} classes |
| * that provide a read-only or updatable view of a set of file store attributes. |
| * |
| * @since 1.7 |
| */ |
| |
| public abstract class FileStore { |
| |
| /** |
| * Initializes a new instance of this class. |
| */ |
| protected FileStore() { |
| } |
| |
| /** |
| * Returns the name of this file store. The format of the name is highly |
| * implementation specific. It will typically be the name of the storage |
| * pool or volume. |
| * |
| * <p> The string returned by this method may differ from the string |
| * returned by the {@link Object#toString() toString} method. |
| * |
| * @return the name of this file store |
| */ |
| public abstract String name(); |
| |
| /** |
| * Returns the <em>type</em> of this file store. The format of the string |
| * returned by this method is highly implementation specific. It may |
| * indicate, for example, the format used or if the file store is local |
| * or remote. |
| * |
| * @return a string representing the type of this file store |
| */ |
| public abstract String type(); |
| |
| /** |
| * Tells whether this file store is read-only. A file store is read-only if |
| * it does not support write operations or other changes to files. Any |
| * attempt to create a file, open an existing file for writing etc. causes |
| * an {@code IOException} to be thrown. |
| * |
| * @return {@code true} if, and only if, this file store is read-only |
| */ |
| public abstract boolean isReadOnly(); |
| |
| /** |
| * Returns the size, in bytes, of the file store. |
| * |
| * @return the size of the file store, in bytes |
| * |
| * @throws IOException |
| * if an I/O error occurs |
| */ |
| public abstract long getTotalSpace() throws IOException; |
| |
| /** |
| * Returns the number of bytes available to this Java virtual machine on the |
| * file store. |
| * |
| * <p> The returned number of available bytes is a hint, but not a |
| * guarantee, that it is possible to use most or any of these bytes. The |
| * number of usable bytes is most likely to be accurate immediately |
| * after the space attributes are obtained. It is likely to be made inaccurate |
| * by any external I/O operations including those made on the system outside |
| * of this Java virtual machine. |
| * |
| * @return the number of bytes available |
| * |
| * @throws IOException |
| * if an I/O error occurs |
| */ |
| public abstract long getUsableSpace() throws IOException; |
| |
| /** |
| * Returns the number of unallocated bytes in the file store. |
| * |
| * <p> The returned number of unallocated bytes is a hint, but not a |
| * guarantee, that it is possible to use most or any of these bytes. The |
| * number of unallocated bytes is most likely to be accurate immediately |
| * after the space attributes are obtained. It is likely to be |
| * made inaccurate by any external I/O operations including those made on |
| * the system outside of this virtual machine. |
| * |
| * @return the number of unallocated bytes |
| * |
| * @throws IOException |
| * if an I/O error occurs |
| */ |
| public abstract long getUnallocatedSpace() throws IOException; |
| |
| /** |
| * Tells whether or not this file store supports the file attributes |
| * identified by the given file attribute view. |
| * |
| * <p> Invoking this method to test if the file store supports {@link |
| * BasicFileAttributeView} will always return {@code true}. In the case of |
| * the default provider, this method cannot guarantee to give the correct |
| * result when the file store is not a local storage device. The reasons for |
| * this are implementation specific and therefore unspecified. |
| * |
| * @param type |
| * the file attribute view type |
| * |
| * @return {@code true} if, and only if, the file attribute view is |
| * supported |
| */ |
| public abstract boolean supportsFileAttributeView(Class<? extends FileAttributeView> type); |
| |
| /** |
| * Tells whether or not this file store supports the file attributes |
| * identified by the given file attribute view. |
| * |
| * <p> Invoking this method to test if the file store supports {@link |
| * BasicFileAttributeView}, identified by the name "{@code basic}" will |
| * always return {@code true}. In the case of the default provider, this |
| * method cannot guarantee to give the correct result when the file store is |
| * not a local storage device. The reasons for this are implementation |
| * specific and therefore unspecified. |
| * |
| * @param name |
| * the {@link FileAttributeView#name name} of file attribute view |
| * |
| * @return {@code true} if, and only if, the file attribute view is |
| * supported |
| */ |
| public abstract boolean supportsFileAttributeView(String name); |
| |
| /** |
| * Returns a {@code FileStoreAttributeView} of the given type. |
| * |
| * <p> This method is intended to be used where the file store attribute |
| * view defines type-safe methods to read or update the file store attributes. |
| * The {@code type} parameter is the type of the attribute view required and |
| * the method returns an instance of that type if supported. |
| * |
| * @param <V> |
| * The {@code FileStoreAttributeView} type |
| * @param type |
| * the {@code Class} object corresponding to the attribute view |
| * |
| * @return a file store attribute view of the specified type or |
| * {@code null} if the attribute view is not available |
| */ |
| public abstract <V extends FileStoreAttributeView> V |
| getFileStoreAttributeView(Class<V> type); |
| |
| /** |
| * Reads the value of a file store attribute. |
| * |
| * <p> The {@code attribute} parameter identifies the attribute to be read |
| * and takes the form: |
| * <blockquote> |
| * <i>view-name</i><b>:</b><i>attribute-name</i> |
| * </blockquote> |
| * where the character {@code ':'} stands for itself. |
| * |
| * <p> <i>view-name</i> is the {@link FileStoreAttributeView#name name} of |
| * a {@link FileStore AttributeView} that identifies a set of file attributes. |
| * <i>attribute-name</i> is the name of the attribute. |
| * |
| * <p> <b>Usage Example:</b> |
| * Suppose we want to know if ZFS compression is enabled (assuming the "zfs" |
| * view is supported): |
| * <pre> |
| * boolean compression = (Boolean)fs.getAttribute("zfs:compression"); |
| * </pre> |
| * |
| * @param attribute |
| * the attribute to read |
| |
| * @return the attribute value; {@code null} may be a valid valid for some |
| * attributes |
| * |
| * @throws UnsupportedOperationException |
| * if the attribute view is not available or it does not support |
| * reading the attribute |
| * @throws IOException |
| * if an I/O error occurs |
| */ |
| public abstract Object getAttribute(String attribute) throws IOException; |
| } |
