org.apache.poi.util

Class IOUtils

java.lang.Object

org.apache.poi.util.IOUtils

public final class IOUtils
extends java.lang.Object

Method Summary

Modifier and Type	Method and Description
static long	calculateChecksum(byte[] data)
static void	closeQuietly(java.io.Closeable closeable) Quietly (no exceptions) close Closable resource.
static void	copy(java.io.InputStream inp, java.io.OutputStream out) Copies all the data from the given InputStream to the OutputStream.
static byte[]	peekFirst8Bytes(java.io.InputStream stream) Peeks at the first 8 bytes of the stream.
static int	readFully(java.io.InputStream in, byte[] b) Helper method, just calls readFully(in, b, 0, b.length)
static int	readFully(java.io.InputStream in, byte[] b, int off, int len) Same as the normal in.read(b, off, len), but tries to ensure that the entire len number of bytes is read.
static int	readFully(java.nio.channels.ReadableByteChannel channel, java.nio.ByteBuffer b) Same as the normal channel.read(b), but tries to ensure that the entire len number of bytes is read.
static byte[]	toByteArray(java.nio.ByteBuffer buffer, int length) Returns an array (that shouldn't be written to!) of the ByteBuffer.
static byte[]	toByteArray(java.io.InputStream stream) Reads all the data from the input stream, and returns the bytes read.

Methods inherited from class java.lang.Object

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

Method Detail

peekFirst8Bytes

public static byte[] peekFirst8Bytes(java.io.InputStream stream)
                              throws java.io.IOException,
                                     EmptyFileException

Peeks at the first 8 bytes of the stream. Returns those bytes, but with the stream unaffected. Requires a stream that supports mark/reset, or a PushbackInputStream. If the stream has >0 but <8 bytes, remaining bytes will be zero.

Throws:

EmptyFileException - if the stream is empty

java.io.IOException

toByteArray

public static byte[] toByteArray(java.io.InputStream stream)
                          throws java.io.IOException

Reads all the data from the input stream, and returns the bytes read.

Throws:

java.io.IOException

toByteArray

public static byte[] toByteArray(java.nio.ByteBuffer buffer,
                                 int length)

Returns an array (that shouldn't be written to!) of the ByteBuffer. Will be of the requested length, or possibly longer if that's easier.

readFully

public static int readFully(java.io.InputStream in,
                            byte[] b)
                     throws java.io.IOException

Helper method, just calls readFully(in, b, 0, b.length)

Throws:

java.io.IOException

readFully

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

Same as the normal in.read(b, off, len), but tries to ensure that the entire len number of bytes is read.

If the end of file is reached before any bytes are read, returns -1. If the end of the file is reached after some bytes are read, returns the number of bytes read. If the end of the file isn't reached before len bytes have been read, will return len bytes.

Throws:

java.io.IOException

readFully

public static int readFully(java.nio.channels.ReadableByteChannel channel,
                            java.nio.ByteBuffer b)
                     throws java.io.IOException

Same as the normal channel.read(b), but tries to ensure that the entire len number of bytes is read.

If the end of file is reached before any bytes are read, returns -1. If the end of the file is reached after some bytes are read, returns the number of bytes read. If the end of the file isn't reached before len bytes have been read, will return len bytes.

Throws:

java.io.IOException

copy

public static void copy(java.io.InputStream inp,
                        java.io.OutputStream out)
                 throws java.io.IOException

Copies all the data from the given InputStream to the OutputStream. It leaves both streams open, so you will still need to close them once done.

Throws:

java.io.IOException

calculateChecksum

public static long calculateChecksum(byte[] data)

closeQuietly

public static void closeQuietly(java.io.Closeable closeable)

Quietly (no exceptions) close Closable resource. In case of error it will be printed to IOUtils class logger.

Parameters:

closeable - resource to close