com.impossibl.postgres.utils.guava

Class ByteStreams

java.lang.Object

com.impossibl.postgres.utils.guava.ByteStreams

public final class ByteStreams
extends Object

Provides utility methods for working with byte arrays and I/O streams.

Since:

1.0

Author:

Chris Nokleberg, Colin Decker

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	ByteStreams.LimitedInputStream

Method Summary

Methods

Modifier and Type	Method and Description
static long	copy(InputStream from, OutputStream to) Copies all bytes from the input stream to the output stream.
static long	copy(ReadableByteChannel from, WritableByteChannel to) Copies all bytes from the readable channel to the writable channel.
static InputStream	limit(InputStream in, long limit) Wraps a InputStream, limiting the number of bytes which can be read.
static OutputStream	nullOutputStream() Returns an OutputStream that simply discards written bytes.
static int	read(InputStream in, byte[] b, int off, int len) Reads some bytes from an input stream and stores them into the buffer array b.
static void	readFully(InputStream in, byte[] b) Attempts to read enough bytes from the stream to fill the given byte array.
static void	readFully(InputStream in, byte[] b, int off, int len) Attempts to read len bytes from the stream into the given array starting at off.
static void	skipFully(InputStream in, long n) Discards n bytes of data from the input stream.
static byte[]	toByteArray(InputStream in) Reads all bytes from an input stream into a byte array.

Methods inherited from class java.lang.Object

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

Method Detail

copy

public static long copy(InputStream from,
        OutputStream to)
                 throws IOException

Copies all bytes from the input stream to the output stream. Does not close or flush either stream.

Parameters:

from - the input stream to read from

to - the output stream to write to

Returns:

the number of bytes copied

Throws:

IOException - if an I/O error occurs

copy

public static long copy(ReadableByteChannel from,
        WritableByteChannel to)
                 throws IOException

Copies all bytes from the readable channel to the writable channel. Does not close or flush either channel.

Parameters:

from - the readable channel to read from

to - the writable channel to write to

Returns:

the number of bytes copied

Throws:

IOException - if an I/O error occurs

toByteArray

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

Reads all bytes from an input stream into a byte array. Does not close the stream.

Parameters:

in - the input stream to read from

Returns:

a byte array containing all the bytes from the stream

Throws:

IOException - if an I/O error occurs

nullOutputStream

public static OutputStream nullOutputStream()

Returns an OutputStream that simply discards written bytes.

Since:

14.0 (since 1.0 as com.google.common.io.NullOutputStream)

limit

public static InputStream limit(InputStream in,
                long limit)

Wraps a InputStream, limiting the number of bytes which can be read.

Parameters:

in - the input stream to be wrapped

limit - the maximum number of bytes to be read

Returns:

a length-limited InputStream

Since:

14.0 (since 1.0 as com.google.common.io.LimitInputStream)

readFully

public static void readFully(InputStream in,
             byte[] b)
                      throws IOException

Attempts to read enough bytes from the stream to fill the given byte array. Does not close the stream.

Parameters:

in - the input stream to read from.

b - the buffer into which the data is read.

Throws:

EOFException - if this stream reaches the end before reading all the bytes.

IOException - if an I/O error occurs.

readFully

public static void readFully(InputStream in,
             byte[] b,
             int off,
             int len)
                      throws IOException

Attempts to read len bytes from the stream into the given array starting at off. Does not close the stream.

Parameters:

in - the input stream to read from.

b - the buffer into which the data is read.

off - an int specifying the offset into the data.

len - an int specifying the number of bytes to read.

Throws:

EOFException - if this stream reaches the end before reading all the bytes.

IOException - if an I/O error occurs.

skipFully

public static void skipFully(InputStream in,
             long n)
                      throws IOException

Discards n bytes of data from the input stream. This method will block until the full amount has been skipped. Does not close the stream.

Parameters:

in - the input stream to read from

n - the number of bytes to skip

Throws:

EOFException - if this stream reaches the end before skipping all the bytes

IOException - if an I/O error occurs, or the stream does not support skipping

read

public static int read(InputStream in,
       byte[] b,
       int off,
       int len)
                throws IOException

Reads some bytes from an input stream and stores them into the buffer array b. This method blocks until len bytes of input data have been read into the array, or end of file is detected. The number of bytes read is returned, possibly zero. Does not close the stream.

A caller can detect EOF if the number of bytes read is less than len. All subsequent calls on the same stream will return zero.

If b is null, a NullPointerException is thrown. If off is negative, or len is negative, or off+len is greater than the length of the array b, then an IndexOutOfBoundsException is thrown. If len is zero, then no bytes are read. Otherwise, the first byte read is stored into element b[off], the next one into b[off+1], and so on. The number of bytes read is, at most, equal to len.

Parameters:

in - the input stream to read from

b - the buffer into which the data is read

off - an int specifying the offset into the data

len - an int specifying the number of bytes to read

Returns:

the number of bytes read

Throws:

IOException - if an I/O error occurs