org.apache.pdfbox.io.RandomAccessFile Maven / Gradle / Ivy
/*
* 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.pdfbox.io;
import java.io.File;
import java.io.FileNotFoundException;
import java.io.IOException;
/**
* A RandomAccess implementation which allows data to be stored in a scratch file on the disk to
* reduce memory consumption.
*
* @author Ben Litchfield
*/
public class RandomAccessFile implements RandomAccess
{
private final java.io.RandomAccessFile ras;
private boolean isClosed;
/**
* Constructor.
*
* @param file The file to write the data to.
* @param mode The writing mode.
* @throws FileNotFoundException If the file cannot be created.
*/
public RandomAccessFile(File file, String mode) throws FileNotFoundException
{
ras = new java.io.RandomAccessFile(file, mode);
}
@Override
public void close() throws IOException
{
ras.close();
isClosed = true;
}
@Override
public void clear() throws IOException
{
checkClosed();
ras.seek(0);
ras.setLength(0);
}
@Override
public void seek(long position) throws IOException
{
checkClosed();
ras.seek(position);
}
@Override
public long getPosition() throws IOException
{
checkClosed();
return ras.getFilePointer();
}
@Override
public int read() throws IOException
{
checkClosed();
return ras.read();
}
@Override
public int read(byte[] b) throws IOException
{
checkClosed();
return ras.read(b);
}
@Override
public int read(byte[] b, int offset, int length) throws IOException
{
checkClosed();
return ras.read(b, offset, length);
}
@Override
public long length() throws IOException
{
checkClosed();
return ras.length();
}
/**
* Ensure that the RandomAccessFile is not closed
*
* @throws IOException
*/
private void checkClosed() throws IOException
{
if (isClosed)
{
throw new IOException("RandomAccessFile already closed");
}
}
@Override
public boolean isClosed()
{
return isClosed;
}
@Override
public void write(byte[] b, int offset, int length) throws IOException
{
checkClosed();
ras.write(b, offset, length);
}
@Override
public void write(byte[] b) throws IOException
{
write(b, 0, b.length);
}
@Override
public void write(int b) throws IOException
{
checkClosed();
ras.write(b);
}
@Override
public int peek() throws IOException
{
int result = read();
if (result != -1)
{
rewind(1);
}
return result;
}
@Override
public void rewind(int bytes) throws IOException
{
checkClosed();
ras.seek(ras.getFilePointer() - bytes);
}
@Override
public byte[] readFully(int length) throws IOException
{
checkClosed();
byte[] b = new byte[length];
ras.readFully(b);
return b;
}
@Override
public boolean isEOF() throws IOException
{
return peek() == -1;
}
@Override
public int available() throws IOException
{
checkClosed();
return (int) Math.min(ras.length() - getPosition(), Integer.MAX_VALUE);
}
}