de.mklinger.commons.exec.io

Class IOUtils

java.lang.Object

de.mklinger.commons.exec.io.IOUtils

public class IOUtils
extends Object

General IO stream manipulation utilities.

This class provides static utility methods for input/output operations.

It was taken from commons-io:commons-io:2.6 and stripped down to the functionality actually used by this library.

Field Summary

Fields

Modifier and Type	Field and Description
static int	EOF Represents the end-of-file (or stream).

Method Summary

Modifier and Type	Method and Description
static int	copy(InputStream input, OutputStream output) Copies bytes from an InputStream to an OutputStream.
static long	copy(InputStream input, OutputStream output, int bufferSize) Copies bytes from an InputStream to an OutputStream using an internal buffer of the given size.
static long	copyLarge(InputStream input, OutputStream output) Copies bytes from a large (over 2GB) InputStream to an OutputStream.
static long	copyLarge(InputStream input, OutputStream output, byte[] buffer) Copies bytes from a large (over 2GB) InputStream to an OutputStream.
static long	copyLarge(InputStream input, OutputStream output, long inputOffset, long length) Copies some or all bytes from a large (over 2GB) InputStream to an OutputStream, optionally skipping input bytes.
static long	copyLarge(InputStream input, OutputStream output, long inputOffset, long length, byte[] buffer) Copies some or all bytes from a large (over 2GB) InputStream to an OutputStream, optionally skipping input bytes.
static long	skip(InputStream input, long toSkip) Skips bytes from an input byte stream.
static void	skipFully(InputStream input, long toSkip) Skips the requested number of bytes or fail if there are not enough left.

Methods inherited from class java.lang.Object

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

Field Detail

EOF

public static final int EOF

Represents the end-of-file (or stream).

Since:

2.5 (made public)

See Also:

Constant Field Values

Method Detail

copy

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

Copies bytes from an InputStream to an OutputStream.

This method buffers the input internally, so there is no need to use a BufferedInputStream.

Large streams (over 2GB) will return a bytes copied value of -1 after the copy has completed since the correct number of bytes cannot be returned as an int. For large streams use the copyLarge(InputStream, OutputStream) method.

Parameters:

input - the InputStream to read from

output - the OutputStream to write to

Returns:

the number of bytes copied, or -1 if > Integer.MAX_VALUE

Throws:

NullPointerException - if the input or output is null

IOException - if an I/O error occurs

Since:

1.1

copy

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

Copies bytes from an InputStream to an OutputStream using an internal buffer of the given size.

This method buffers the input internally, so there is no need to use a BufferedInputStream.

Parameters:

input - the InputStream to read from

output - the OutputStream to write to

bufferSize - the bufferSize used to copy from the input to the output

Returns:

the number of bytes copied

Throws:

NullPointerException - if the input or output is null

IOException - if an I/O error occurs

Since:

2.5

copyLarge

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

Copies bytes from a large (over 2GB) InputStream to an OutputStream.

This method buffers the input internally, so there is no need to use a BufferedInputStream.

The buffer size is given by DEFAULT_BUFFER_SIZE.

Parameters:

input - the InputStream to read from

output - the OutputStream to write to

Returns:

the number of bytes copied

Throws:

NullPointerException - if the input or output is null

IOException - if an I/O error occurs

Since:

1.3

copyLarge

public static long copyLarge(InputStream input,
                             OutputStream output,
                             byte[] buffer)
                      throws IOException

Copies bytes from a large (over 2GB) InputStream to an OutputStream.

This method uses the provided buffer, so there is no need to use a BufferedInputStream.

Parameters:

input - the InputStream to read from

output - the OutputStream to write to

buffer - the buffer to use for the copy

Returns:

the number of bytes copied

Throws:

NullPointerException - if the input or output is null

IOException - if an I/O error occurs

Since:

2.2

copyLarge

public static long copyLarge(InputStream input,
                             OutputStream output,
                             long inputOffset,
                             long length)
                      throws IOException

Copies some or all bytes from a large (over 2GB) InputStream to an OutputStream, optionally skipping input bytes.

This method buffers the input internally, so there is no need to use a BufferedInputStream.

Note that the implementation uses skip(InputStream, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped.

The buffer size is given by DEFAULT_BUFFER_SIZE.

Parameters:

input - the InputStream to read from

output - the OutputStream to write to

inputOffset - : number of bytes to skip from input before copying -ve values are ignored

length - : number of bytes to copy. -ve means all

Returns:

the number of bytes copied

Throws:

NullPointerException - if the input or output is null

IOException - if an I/O error occurs

Since:

2.2

copyLarge

public static long copyLarge(InputStream input,
                             OutputStream output,
                             long inputOffset,
                             long length,
                             byte[] buffer)
                      throws IOException

Copies some or all bytes from a large (over 2GB) InputStream to an OutputStream, optionally skipping input bytes.

This method uses the provided buffer, so there is no need to use a BufferedInputStream.

Note that the implementation uses skip(InputStream, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped.

Parameters:

input - the InputStream to read from

output - the OutputStream to write to

inputOffset - : number of bytes to skip from input before copying -ve values are ignored

length - : number of bytes to copy. -ve means all

buffer - the buffer to use for the copy

Returns:

the number of bytes copied

Throws:

NullPointerException - if the input or output is null

IOException - if an I/O error occurs

Since:

2.2

skip

public static long skip(InputStream input,
                        long toSkip)
                 throws IOException

Skips bytes from an input byte stream. This implementation guarantees that it will read as many bytes as possible before giving up; this may not always be the case for skip() implementations in subclasses of InputStream.

Note that the implementation uses InputStream.read(byte[], int, int) rather than delegating to InputStream.skip(long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of bytes are skipped.

Parameters:

input - byte stream to skip

toSkip - number of bytes to skip.

Returns:

number of bytes actually skipped.

Throws:

IOException - if there is a problem reading the file

IllegalArgumentException - if toSkip is negative

Since:

2.0

See Also:

InputStream.skip(long), IO-203 - Add skipFully() method for InputStreams

skipFully

public static void skipFully(InputStream input,
                             long toSkip)
                      throws IOException

Skips the requested number of bytes or fail if there are not enough left.

This allows for the possibility that InputStream.skip(long) may not skip as many bytes as requested (most likely because of reaching EOF).

Note that the implementation uses skip(InputStream, long). This means that the method may be considerably less efficient than using the actual skip implementation, this is done to guarantee that the correct number of characters are skipped.

Parameters:

input - stream to skip

toSkip - the number of bytes to skip

Throws:

IOException - if there is a problem reading the file

IllegalArgumentException - if toSkip is negative

EOFException - if the number of bytes skipped was incorrect

Since:

2.0

See Also:

InputStream.skip(long)