Package org.apache.pdfbox.io

Class IOUtils

java.lang.Object

org.apache.pdfbox.io.IOUtils

public final class IOUtils
extends Object

This class contains various I/O-related methods.

Method Summary

Modifier and Type	Method	Description
static IOException	closeAndLogException(Closeable closeable, org.apache.commons.logging.Log logger, String resourceName, IOException initialException)	Try to close an IO resource and log and return if there was an exception.
static void	closeQuietly(Closeable closeable)	Null safe close of the given Closeable suppressing any exception.
static long	copy(InputStream input, OutputStream output)	Copies all the contents from the given input stream to the given output stream.
static RandomAccessStreamCache.StreamCacheCreateFunction	createMemoryOnlyStreamCache()	Provides a function to create an instance of a memory only StreamCache using unrestricted main memory.
static Path	createProtectedTempDir()	Creates a temporary directory in the default temporary-file directory with owner-only permissions and registers a shutdown hook to delete it on JVM exit.
static Path	createProtectedTempFile(Path dir, String prefix, String suffix)	Creates a temporary file in the specified directory (or default temporary-file directory if null) with owner-only permissions.
static RandomAccessStreamCache.StreamCacheCreateFunction	createTempFileOnlyStreamCache()	Provides a function to create an instance of a temp file only StreamCache using unrestricted size.
static long	populateBuffer(InputStream in, byte[] buffer)	Populates the given buffer with data read from the input stream.
static byte[]	toByteArray(InputStream in)	Reads the input stream and returns its contents as a byte array.
static void	unmap(ByteBuffer buf)	Unmap memory mapped byte buffers.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

toByteArray

public static byte[] toByteArray(InputStream in)
                          throws IOException

Reads the input stream and returns its contents as a byte array.

Parameters:

in - the input stream to read from.

Returns:

the byte array

Throws:

IOException - if an I/O error occurs

copy

public static long copy(InputStream input,
 OutputStream output)
                 throws IOException

Copies all the contents from the given input stream to the given output stream.

Parameters:

input - the input stream

output - the output stream

Returns:

the number of bytes that have been copied

Throws:

IOException - if an I/O error occurs

populateBuffer

public static long populateBuffer(InputStream in,
 byte[] buffer)
                           throws IOException

Populates the given buffer with data read from the input stream. If the data doesn't fit the buffer, only the data that fits in the buffer is read. If the data is less than fits in the buffer, the buffer is not completely filled.

Parameters:

in - the input stream to read from

buffer - the buffer to fill

Returns:

the number of bytes written to the buffer

Throws:

IOException - if an I/O error occurs

closeQuietly

public static void closeQuietly(Closeable closeable)

Null safe close of the given Closeable suppressing any exception.

Parameters:

closeable - to be closed

closeAndLogException

public static IOException closeAndLogException(Closeable closeable,
 org.apache.commons.logging.Log logger,
 String resourceName,
 IOException initialException)

Try to close an IO resource and log and return if there was an exception.

An exception is only returned if the IOException passed in is null.

Parameters:

closeable - to be closed

logger - the logger to be used so that logging appears under that log instance

resourceName - the name to appear in the log output

initialException - if set, this exception will be returned even where there is another exception while closing the IO resource

Returns:

the IOException is there was any but only if initialException is null

unmap

public static void unmap(ByteBuffer buf)

Unmap memory mapped byte buffers. This is a hack waiting for a proper JVM provided solution mentioned in JDK-4724038: Add unmap method to MappedByteBuffer. The issue here is that even when closed, memory mapped byte buffers hold a lock on the underlying file until GC is executing and this in turns result in an error if the user tries to move or delete the file.

Parameters:

buf - the buffer to be unmapped

createMemoryOnlyStreamCache

public static RandomAccessStreamCache.StreamCacheCreateFunction createMemoryOnlyStreamCache()

Provides a function to create an instance of a memory only StreamCache using unrestricted main memory. RandomAccessReadWriteBuffer is used as current default implementation.

Returns:

a function to create an instance of a memory only StreamCache using unrestricted main memory

createTempFileOnlyStreamCache

public static RandomAccessStreamCache.StreamCacheCreateFunction createTempFileOnlyStreamCache()

Provides a function to create an instance of a temp file only StreamCache using unrestricted size. ScratchFile is used as current default implementation.

Returns:

a function to create an instance of a temp file only StreamCache using unrestricted size

createProtectedTempDir

public static Path createProtectedTempDir()
                                   throws IOException

Creates a temporary directory in the default temporary-file directory with owner-only permissions and registers a shutdown hook to delete it on JVM exit.

Note: This method is designed to be used for storing temporary files that may contain sensitive data in a temporary directories with restricted permissions, to mitigate the risk of unauthorized access by other users or processes on the same system. Used e.g. by PDFDebugger.

Returns:

the path to the created temporary directory

Throws:

IOException

createProtectedTempFile

public static Path createProtectedTempFile(Path dir,
 String prefix,
 String suffix)
                                    throws IOException

Creates a temporary file in the specified directory (or default temporary-file directory if null) with owner-only permissions.

This method attempts to set owner-only permissions at file creation time when supported, to minimize the time window during which the file may have default (world-readable) permissions. On POSIX systems (Linux, macOS), permissions are set during creation. On Windows, permissions are set after file creation via ACL.

Note: This method is designed for storing temporary files that may contain sensitive data in a temporary directory with restricted permissions, to mitigate the risk of unauthorized access by other users or processes on the same system. However, unlike createProtectedTempDir(), this method does NOT automatically delete the file on JVM shutdown. The caller is responsible for deleting the temporary file when no longer needed. Used e.g. by PDFDebugger.

Parameters:

dir - the directory in which to create the temporary file, or null to use the default temporary-file directory

prefix - the prefix string to be used in generating the file's name; may be null

suffix - the suffix string to be used in generating the file's name; may be null

Returns:

the path to the created temporary file with owner-only permissions

Throws:

IOException - if an I/O error occurs during file creation or permission setting

SecurityException - if a security manager is installed and denies access

See Also:

• createProtectedTempDir()
• Files.createTempFile(Path, String, String, FileAttribute[])