com.google.api.client.util

Class ByteStreams

java.lang.Object

com.google.api.client.util.ByteStreams

public final class ByteStreams
extends Object

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

NOTE: this is a copy of a subset of Guava's ByteStreams. The implementation must match as closely as possible to Guava's implementation.

Since:

1.14

Author:

Yaniv Inbar

Method Summary

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 InputStream	limit(InputStream in, long limit) Wraps an input stream, limiting the number of bytes which can be read.
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.

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

limit

public static InputStream limit(InputStream in,
                                long limit)

Wraps an input stream, 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

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