| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.hadoop.fs; |
| |
| import java.io.*; |
| |
| /** Utility that wraps a {@link FSInputStream} in a {@link DataInputStream} |
| * and buffers input through a {@link BufferedInputStream}. */ |
| public class FSDataInputStream extends DataInputStream |
| implements Seekable, PositionedReadable, Closeable { |
| |
| public FSDataInputStream(InputStream in) |
| throws IOException { |
| super(in); |
| if( !(in instanceof Seekable) || !(in instanceof PositionedReadable) ) { |
| throw new IllegalArgumentException( |
| "In is not an instance of Seekable or PositionedReadable"); |
| } |
| } |
| |
| public synchronized void seek(long desired) throws IOException { |
| ((Seekable)in).seek(desired); |
| } |
| |
| public long getPos() throws IOException { |
| return ((Seekable)in).getPos(); |
| } |
| |
| public int read(long position, byte[] buffer, int offset, int length) |
| throws IOException { |
| return ((PositionedReadable)in).read(position, buffer, offset, length); |
| } |
| |
| public void readFully(long position, byte[] buffer, int offset, int length) |
| throws IOException { |
| ((PositionedReadable)in).readFully(position, buffer, offset, length); |
| } |
| |
| public void readFully(long position, byte[] buffer) |
| throws IOException { |
| ((PositionedReadable)in).readFully(position, buffer, 0, buffer.length); |
| } |
| |
| public boolean seekToNewSource(long targetPos) throws IOException { |
| return ((Seekable)in).seekToNewSource(targetPos); |
| } |
| } |