< prev index next >

src/java.base/share/classes/java/nio/file/FileStore.java

Print this page


   1 /*
   2  * Copyright (c) 2007, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any


  95 
  96     /**
  97      * Returns the number of bytes available to this Java virtual machine on the
  98      * file store.
  99      *
 100      * <p> The returned number of available bytes is a hint, but not a
 101      * guarantee, that it is possible to use most or any of these bytes.  The
 102      * number of usable bytes is most likely to be accurate immediately
 103      * after the space attributes are obtained. It is likely to be made inaccurate
 104      * by any external I/O operations including those made on the system outside
 105      * of this Java virtual machine.
 106      *
 107      * @return  the number of bytes available
 108      *
 109      * @throws  IOException
 110      *          if an I/O error occurs
 111      */
 112     public abstract long getUsableSpace() throws IOException;
 113 
 114     /**
























 115      * Returns the number of unallocated bytes in the file store.
 116      *
 117      * <p> The returned number of unallocated bytes is a hint, but not a
 118      * guarantee, that it is possible to use most or any of these bytes.  The
 119      * number of unallocated bytes is most likely to be accurate immediately
 120      * after the space attributes are obtained. It is likely to be
 121      * made inaccurate by any external I/O operations including those made on
 122      * the system outside of this virtual machine.
 123      *
 124      * @return  the number of unallocated bytes
 125      *
 126      * @throws  IOException
 127      *          if an I/O error occurs
 128      */
 129     public abstract long getUnallocatedSpace() throws IOException;
 130 
 131     /**
 132      * Tells whether or not this file store supports the file attributes
 133      * identified by the given file attribute view.
 134      *


   1 /*
   2  * Copyright (c) 2007, 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any


  95 
  96     /**
  97      * Returns the number of bytes available to this Java virtual machine on the
  98      * file store.
  99      *
 100      * <p> The returned number of available bytes is a hint, but not a
 101      * guarantee, that it is possible to use most or any of these bytes.  The
 102      * number of usable bytes is most likely to be accurate immediately
 103      * after the space attributes are obtained. It is likely to be made inaccurate
 104      * by any external I/O operations including those made on the system outside
 105      * of this Java virtual machine.
 106      *
 107      * @return  the number of bytes available
 108      *
 109      * @throws  IOException
 110      *          if an I/O error occurs
 111      */
 112     public abstract long getUsableSpace() throws IOException;
 113 
 114     /**
 115      * Returns the number of bytes per block in this file store.
 116      *
 117      * <p> File storage is typically organized into discrete sequences of bytes
 118      * called <i>blocks</i>. A block is the smallest storage unit of a file store.
 119      * Every read and write operation is performed on a multiple of blocks.
 120      *
 121      * @implSpec The implementation in this class throws an
 122      *         {@code UnsupportedOperationException}.
 123      *
 124      * @return  the block size of this file store, in bytes
 125      *
 126      * @throws  IOException
 127      *          if an I/O error occurs
 128      *
 129      * @throws  UnsupportedOperationException
 130      *          if the operation is not supported
 131      *
 132      * @since 10
 133      */
 134     public long getBlockSize() throws IOException {
 135         throw new UnsupportedOperationException();
 136     }
 137 
 138     /**
 139      * Returns the number of unallocated bytes in the file store.
 140      *
 141      * <p> The returned number of unallocated bytes is a hint, but not a
 142      * guarantee, that it is possible to use most or any of these bytes.  The
 143      * number of unallocated bytes is most likely to be accurate immediately
 144      * after the space attributes are obtained. It is likely to be
 145      * made inaccurate by any external I/O operations including those made on
 146      * the system outside of this virtual machine.
 147      *
 148      * @return  the number of unallocated bytes
 149      *
 150      * @throws  IOException
 151      *          if an I/O error occurs
 152      */
 153     public abstract long getUnallocatedSpace() throws IOException;
 154 
 155     /**
 156      * Tells whether or not this file store supports the file attributes
 157      * identified by the given file attribute view.
 158      *


< prev index next >