com.itextpdf.io.source.RandomAccessSourceFactory Maven / Gradle / Ivy
/*
This file is part of the iText (R) project.
Copyright (c) 1998-2022 iText Group NV
Authors: Bruno Lowagie, Paulo Soares, et al.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License version 3
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following permission added to Section 15 as permitted in Section 7(a):
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or FITNESS FOR A PARTICULAR PURPOSE.
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*/
package com.itextpdf.io.source;
import com.itextpdf.io.exceptions.IOException;
import com.itextpdf.io.util.ResourceUtil;
import com.itextpdf.io.util.StreamUtil;
import com.itextpdf.commons.utils.MessageFormatUtil;
import java.io.File;
import java.io.FileInputStream;
import java.io.InputStream;
import java.io.RandomAccessFile;
import java.net.URL;
import java.nio.channels.FileChannel;
/**
* Factory to create {@link IRandomAccessSource} objects based on various types of sources
*/
public final class RandomAccessSourceFactory {
/**
* The default value for the forceRead flag
*/
private static boolean forceReadDefaultValue = false;
/**
* Whether the full content of the source should be read into memory at construction
*/
private boolean forceRead = forceReadDefaultValue;
/**
* Whether {@link java.io.RandomAccessFile} should be used instead of a {@link java.nio.channels.FileChannel}, where applicable
*/
private boolean usePlainRandomAccess = false;
/**
* Whether the underlying file should have a RW lock on it or just an R lock
*/
private boolean exclusivelyLockFile = false;
/**
* Creates a factory that will give preference to accessing the underling data source using memory mapped files
*/
public RandomAccessSourceFactory() {
}
/**
* Determines the default value for the forceRead flag
* @param forceRead true if by default the full content will be read, false otherwise
*/
public static void setForceReadDefaultValue(boolean forceRead) {
forceReadDefaultValue = forceRead;
}
/**
* Determines whether the full content of the source will be read into memory
* @param forceRead true if the full content will be read, false otherwise
* @return this object (this allows chaining of method calls)
*/
public RandomAccessSourceFactory setForceRead(boolean forceRead){
this.forceRead = forceRead;
return this;
}
/**
* Determines whether {@link java.io.RandomAccessFile} should be used as the primary data access mechanism
* @param usePlainRandomAccess whether {@link java.io.RandomAccessFile} should be used as the primary data access mechanism
* @return this object (this allows chaining of method calls)
*/
public RandomAccessSourceFactory setUsePlainRandomAccess(boolean usePlainRandomAccess){
this.usePlainRandomAccess = usePlainRandomAccess;
return this;
}
public RandomAccessSourceFactory setExclusivelyLockFile(boolean exclusivelyLockFile){
this.exclusivelyLockFile = exclusivelyLockFile;
return this;
}
/**
* Creates a {@link IRandomAccessSource} based on a byte array
* @param data the byte array
* @return the newly created {@link IRandomAccessSource}
*/
public IRandomAccessSource createSource(byte[] data){
return new ArrayRandomAccessSource(data);
}
public IRandomAccessSource createSource(RandomAccessFile raf) throws java.io.IOException {
return new RAFRandomAccessSource(raf);
}
/**
* Creates a {@link IRandomAccessSource} based on a URL. The data available at the URL is read into memory and used
* as the source for the {@link IRandomAccessSource}
* @param url the url to read from
* @return the newly created {@link IRandomAccessSource}
* @throws java.io.IOException in case of any I/O error.
*/
public IRandomAccessSource createSource(URL url) throws java.io.IOException{
InputStream stream = url.openStream();
try {
return createSource(stream);
}
finally {
try {
stream.close();
} catch(java.io.IOException ignored) { }
}
}
/**
* Creates or extracts a {@link IRandomAccessSource} based on an {@link InputStream}.
*
*
* If the InputStream is an instance of {@link RASInputStream} then extracts the source from it.
* Otherwise The full content of the InputStream is read into memory and used
* as the source for the {@link IRandomAccessSource}
*
* @param inputStream the stream to read from
*
* @return the newly created or extracted {@link IRandomAccessSource}
*
* @throws java.io.IOException in case of any I/O error.
*/
public IRandomAccessSource extractOrCreateSource(InputStream inputStream) throws java.io.IOException {
if (inputStream instanceof RASInputStream) {
return ((RASInputStream) inputStream).getSource();
}
return createSource(StreamUtil.inputStreamToArray(inputStream));
}
/**
* Creates a {@link IRandomAccessSource} based on an {@link InputStream}.
*
*
* The full content of the InputStream is read into memory and used
* as the source for the {@link IRandomAccessSource}
*
* @param inputStream the stream to read from
*
* @return the newly created {@link IRandomAccessSource}
*
* @throws java.io.IOException in case of any I/O error.
*/
public IRandomAccessSource createSource(InputStream inputStream) throws java.io.IOException{
return createSource(StreamUtil.inputStreamToArray(inputStream));
}
/**
* Creates a {@link IRandomAccessSource} based on a filename string.
* If the filename describes a URL, a URL based source is created
* If the filename describes a file on disk, the contents may be read into memory (if {@code forceRead} is true),
* opened using memory mapped file channel (if usePlainRandomAccess is false), or
* opened using {@link RandomAccessFile} access (if usePlainRandomAccess is true)
* This call will automatically fail over to using {@link RandomAccessFile} if the memory map operation fails
* @param filename the name of the file or resource to create the {@link IRandomAccessSource} for
* @return the newly created {@link IRandomAccessSource}
* @throws java.io.IOException in case of any I/O error
*/
public IRandomAccessSource createBestSource(String filename) throws java.io.IOException{
File file = new File(filename);
if (!file.canRead()) {
if (filename.startsWith("file:/")
|| filename.startsWith("http://")
|| filename.startsWith("https://")
|| filename.startsWith("jar:")
|| filename.startsWith("wsjar:")
|| filename.startsWith("vfszip:")) {
return createSource(new URL(filename));
} else {
return createByReadingToMemory(filename);
}
}
if (forceRead){
return createByReadingToMemory(new FileInputStream(filename));
}
String openMode = exclusivelyLockFile ? "rw" : "r";
RandomAccessFile raf = new RandomAccessFile(file, openMode);
if (exclusivelyLockFile){
raf.getChannel().lock();
}
if (usePlainRandomAccess){
return new RAFRandomAccessSource(raf);
}
try{
// files with zero length can't be mapped and will throw an IllegalArgumentException.
// Just open using a simple RAF source.
if (raf.length() <= 0)
return new RAFRandomAccessSource(raf);
try {
// ownership of the RAF passes to whatever source is created by createBestSource.
return createBestSource(raf.getChannel());
} catch (java.io.IOException e){
if (exceptionIsMapFailureException(e)) {
return new RAFRandomAccessSource(raf);
}
throw e;
}
} catch (Exception e) {
// If RAFRandomAccessSource constructor or createBestSource throws, then we must close the RAF we created.
try {
raf.close();
} catch (java.io.IOException ignore){}
throw e;
}
}
/**
* Creates a {@link IRandomAccessSource} based on memory mapping a file channel.
* Unless you are explicitly working with a {@code FileChannel} already, it is better to use
* {@link RandomAccessSourceFactory#createBestSource(String)}.
* If the file is large, it will be opened using a paging strategy.
* @param channel the name of the file or resource to create the {@link IRandomAccessSource} for
* @return the newly created {@link IRandomAccessSource}
* @throws java.io.IOException in case of any I/O error
*/
public IRandomAccessSource createBestSource(FileChannel channel) throws java.io.IOException {
// if less than the fully mapped usage of PagedFileChannelRandomAccessSource,
// just map the whole thing and be done with it
if (channel.size() <= PagedChannelRandomAccessSource.DEFAULT_TOTAL_BUFSIZE){
return new GetBufferedRandomAccessSource(new FileChannelRandomAccessSource(channel));
} else {
return new GetBufferedRandomAccessSource(new PagedChannelRandomAccessSource(channel));
}
}
public IRandomAccessSource createRanged(IRandomAccessSource source, long[] ranges) throws java.io.IOException {
IRandomAccessSource[] sources = new IRandomAccessSource[ranges.length/2];
for(int i = 0; i < ranges.length; i+=2){
sources[i/2] = new WindowRandomAccessSource(source, ranges[i], ranges[i+1]);
}
return new GroupedRandomAccessSource(sources);
}
/**
* Creates a new {@link IRandomAccessSource} by reading the specified file/resource into memory
* @param filename the name of the resource to read
* @return the newly created {@link IRandomAccessSource}
* @throws java.io.IOException if reading the underling file or stream fails
*/
private IRandomAccessSource createByReadingToMemory(String filename) throws java.io.IOException {
InputStream stream = ResourceUtil.getResourceStream(filename);
if (stream == null) {
throw new java.io.IOException(MessageFormatUtil.format(IOException._1NotFoundAsFileOrResource, filename));
}
return createByReadingToMemory(stream);
}
/**
* Creates a new {@link IRandomAccessSource} by reading the specified file/resource into memory
* @param stream the name of the resource to read
* @return the newly created {@link IRandomAccessSource}
* @throws java.io.IOException if reading the underling file or stream fails
*/
private IRandomAccessSource createByReadingToMemory(InputStream stream) throws java.io.IOException {
try {
return new ArrayRandomAccessSource(StreamUtil.inputStreamToArray(stream));
}
finally {
try {
stream.close();
} catch (java.io.IOException ignored) { }
}
}
/**
* Utility method that determines whether a given java.io.IOException is the result
* of a failure to map a memory mapped file. It would be better if the runtime
* provided a special exception for this case, but it doesn't, so we have to rely
* on parsing the exception message.
* @param e the exception to check
* @return true if the exception was the result of a failure to map a memory mapped file
*/
private static boolean exceptionIsMapFailureException(java.io.IOException e){
if (e.getMessage() != null && e.getMessage().contains("Map failed"))
return true;
return false;
}
}