/*
* Entagged Audio Tag library
* Copyright (c) 2004-2005 Christian Laireiter <liree@web.de>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*/
package org.jaudiotagger.audio.asf.util;
import org.jaudiotagger.audio.asf.data.AsfHeader;
import org.jaudiotagger.audio.asf.data.GUID;
import org.jaudiotagger.logging.ErrorMessage;
import java.io.EOFException;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
/**
* Some static Methods which are used in several Classes. <br>
*
* @author Christian Laireiter
*/
public class Utils {
public static final long DIFF_BETWEEN_ASF_DATE_AND_JAVA_DATE = 11644470000000l;
/**
* Stores the default line separator of the current underlying system.
*/
public final static String LINE_SEPARATOR = System
.getProperty("line.separator"); //$NON-NLS-1$
/**
*
*/
private static final int MAXIMUM_STRING_LENGTH_ALLOWED = 32766;
/**
* This method checks given string will not exceed limit in bytes[] when
* converted UTF-16LE encoding (2 bytes per character) and checks whether
* the length doesn't exceed 65535 bytes. <br>
*
* @param value
* The string to check.
* @throws IllegalArgumentException
* If byte representation takes more than 65535 bytes.
*/
public static void checkStringLengthNullSafe(String value)
throws IllegalArgumentException {
if (value != null) {
if (value.length() > MAXIMUM_STRING_LENGTH_ALLOWED) {
throw new IllegalArgumentException(
ErrorMessage.WMA_LENGTH_OF_STRING_IS_TOO_LARGE
.getMsg((value.length() * 2)));
}
}
}
/**
*
* @param value String to check for null
* @return true unless string is too long
*/
public static boolean isStringLengthValidNullSafe(String value) {
if (value != null) {
if (value.length() > MAXIMUM_STRING_LENGTH_ALLOWED) {
return false;
}
}
return true;
}
/**
* effectively copies a specified amount of bytes from one stream to
* another.
*
* @param source
* stream to read from
* @param dest
* stream to write to
* @param amount
* amount of bytes to copy
* @throws IOException
* on I/O errors, and if the source stream depletes before all
* bytes have been copied.
*/
public static void copy(InputStream source, OutputStream dest, long amount)
throws IOException {
byte[] buf = new byte[8192];
long copied = 0;
while (copied < amount) {
int toRead = 8192;
if ((amount - copied) < 8192) {
toRead = (int) (amount - copied);
}
int read = source.read(buf, 0, toRead);
if (read == -1) {
throw new IOException(
"Inputstream has to continue for another "
+ (amount - copied) + " bytes.");
}
dest.write(buf, 0, read);
copied += read;
}
}
/**
* Copies all of the source to the destination.<br>
*
* @param source
* source to read from
* @param dest
* stream to write to
* @throws IOException
* on I/O errors.
*/
public static void flush(final InputStream source, final OutputStream dest)
throws IOException {
final byte[] buf = new byte[8192];
int read;
while ((read = source.read(buf)) != -1) {
dest.write(buf, 0, read);
}
}
/**
* This method will create a byte[] at the size of <code>byteCount</code>
* and insert the bytes of <code>value</code> (starting from lowset byte)
* into it. <br>
* You can easily create a Word (16-bit), DWORD (32-bit), QWORD (64 bit) out
* of the value, ignoring the original type of value, since java
* automatically performs transformations. <br>
* <b>Warning: </b> This method works with unsigned numbers only.
*
* @param value
* The value to be written into the result.
* @param byteCount
* The number of bytes the array has got.
* @return A byte[] with the size of <code>byteCount</code> containing the
* lower byte values of <code>value</code>.
*/
public static byte[] getBytes(final long value, final int byteCount) {
byte[] result = new byte[byteCount];
for (int i = 0; i < result.length; i ++) {
result[i] = (byte) ((value >>> (i*8)) & 0xFF);
}
return result;
}
/**
* Convenience method to convert the given string into a byte sequence which
* has the format of the charset given.
*
* @param source
* string to convert.
* @param charset
* charset to apply
* @return the source's binary representation according to the charset.
*/
public static byte[] getBytes(final String source, final Charset charset) {
assert charset != null;
assert source != null;
final ByteBuffer encoded = charset.encode(source);
final byte[] result = new byte[encoded.limit()];
encoded.rewind();
encoded.get(result);
return result;
}
/**
* Since date values in ASF files are given in 100 ns steps since first
* january of 1601 a little conversion must be done. <br>
* This method converts a date given in described manner to a calendar.
*
* @param fileTime
* Time in 100ns since 1 jan 1601
* @return Calendar holding the date representation.
*/
/* Old method that ran very slowely and doesnt logical correct, how does dividing something
at 10-4 by 10,000 convert it to 10 -3
public static GregorianCalendar getDateOf(final BigInteger fileTime) {
final GregorianCalendar result = new GregorianCalendar(1601, 0, 1);
// lose anything beyond milliseconds, because calendar can't handle
// less value
BigInteger time = fileTime.divide(new BigInteger("10000")); //$NON-NLS-1$
final BigInteger maxInt = new BigInteger(String
.valueOf(Integer.MAX_VALUE));
while (time.compareTo(maxInt) > 0) {
result.add(Calendar.MILLISECOND, Integer.MAX_VALUE);
time = time.subtract(maxInt);
}
result.add(Calendar.MILLISECOND, time.intValue());
return result;
}
*/
/**
* Date values in ASF files are given in 100 ns (10 exp -4) steps since first
*
* @param fileTime
* Time in 100ns since 1 jan 1601
* @return Calendar holding the date representation.
*/
public static GregorianCalendar getDateOf(final BigInteger fileTime) {
final GregorianCalendar result = new GregorianCalendar();
// Divide by 10 to convert from -4 to -3 (millisecs)
BigInteger time = fileTime.divide(new BigInteger("10"));
// Construct Date taking into the diff between 1601 and 1970
Date date = new Date(time.longValue() - DIFF_BETWEEN_ASF_DATE_AND_JAVA_DATE);
result.setTime(date);
return result;
}
/**
* Tests if the given string is <code>null</code> or just contains
* whitespace characters.
*
* @param toTest
* String to test.
* @return see description.
*/
public static boolean isBlank(String toTest) {
if (toTest == null)
{
return true;
}
for (int i = 0; i < toTest.length(); i++)
{
if(!Character.isWhitespace(toTest.charAt(i)))
{
return false;
}
}
return true;
}
/**
* Reads 8 bytes from stream and interprets them as a UINT64 which is
* returned as {@link BigInteger}.<br>
*
* @param stream
* stream to readm from.
* @return a BigInteger which represents the read 8 bytes value.
* @throws IOException if problem reading bytes
*/
public static BigInteger readBig64(InputStream stream) throws IOException {
byte[] bytes = new byte[8];
byte[] oa = new byte[8];
int read = stream.read(bytes);
if (read != 8) {
// 8 bytes mandatory.
throw new EOFException();
}
for (int i = 0; i < bytes.length; i++) {
oa[7 - i] = bytes[i];
}
return new BigInteger(oa);
}
/**
* Reads <code>size</code> bytes from the stream.<br>
*
* @param stream
* stream to read from.
* @param size
* amount of bytes to read.
* @return the read bytes.
* @throws IOException
* on I/O errors.
*/
public static byte[] readBinary(InputStream stream, long size)
throws IOException {
byte[] result = new byte[(int) size];
stream.read(result);
return result;
}
/**
* This method reads a UTF-16 String, which length is given on the number of
* characters it consists of. <br>
* The stream must be at the number of characters. This number contains the
* terminating zero character (UINT16).
*
* @param stream
* Input source
* @return String
* @throws IOException
* read errors
*/
public static String readCharacterSizedString(InputStream stream)
throws IOException {
StringBuilder result = new StringBuilder();
int strLen = readUINT16(stream);
int character = stream.read();
character |= stream.read() << 8;
do {
if (character != 0) {
result.append((char) character);
character = stream.read();
character |= stream.read() << 8;
}
} while (character != 0 || (result.length() + 1) > strLen);
if (strLen != (result.length() + 1)) {
throw new IllegalStateException(
"Invalid Data for current interpretation"); //$NON-NLS-1$
}
return result.toString();
}
/**
* This method reads a UTF-16 encoded String. <br>
* For the use this method the number of bytes used by current string must
* be known. <br>
* The ASF specification recommends that those strings end with a
* terminating zero. However it also says that it is not always the case.
*
* @param stream
* Input source
* @param strLen
* Number of bytes the String may take.
* @return read String.
* @throws IOException
* read errors.
*/
public static String readFixedSizeUTF16Str(InputStream stream, int strLen)
throws IOException {
byte[] strBytes = new byte[strLen];
int read = stream.read(strBytes);
if (read == strBytes.length) {
if (strBytes.length >= 2) {
/*
* Zero termination is recommended but optional. So check and
* if, remove.
*/
if (strBytes[strBytes.length - 1] == 0
&& strBytes[strBytes.length - 2] == 0) {
byte[] copy = new byte[strBytes.length - 2];
System.arraycopy(strBytes, 0, copy, 0, strBytes.length - 2);
strBytes = copy;
}
}
return new String(strBytes, "UTF-16LE");
}
throw new IllegalStateException(
"Couldn't read the necessary amount of bytes.");
}
/**
* This Method reads a GUID (which is a 16 byte long sequence) from the
* given <code>raf</code> and creates a wrapper. <br>
* <b>Warning </b>: <br>
* There is no way of telling if a byte sequence is a guid or not. The next
* 16 bytes will be interpreted as a guid, whether it is or not.
*
* @param stream
* Input source.
* @return A class wrapping the guid.
* @throws IOException
* happens when the file ends before guid could be extracted.
*/
public static GUID readGUID(InputStream stream) throws IOException {
if (stream == null) {
throw new IllegalArgumentException("Argument must not be null"); //$NON-NLS-1$
}
int[] binaryGuid = new int[GUID.GUID_LENGTH];
for (int i = 0; i < binaryGuid.length; i++) {
binaryGuid[i] = stream.read();
}
return new GUID(binaryGuid);
}
/**
* Reads 2 bytes from stream and interprets them as UINT16.<br>
*
* @param stream
* stream to read from.
* @return UINT16 value
* @throws IOException
* on I/O Errors.
*/
public static int readUINT16(InputStream stream) throws IOException {
int result = stream.read();
result |= stream.read() << 8;
return result;
}
/**
* Reads 4 bytes from stream and interprets them as UINT32.<br>
*
* @param stream
* stream to read from.
* @return UINT32 value
* @throws IOException
* on I/O Errors.
*/
public static long readUINT32(InputStream stream) throws IOException {
long result = 0;
for (int i = 0; i <= 24; i += 8) {
// Warning, always cast to long here. Otherwise it will be
// shifted as int, which may produce a negative value, which will
// then be extended to long and assign the long variable a negative
// value.
result |= (long) stream.read() << i;
}
return result;
}
/**
* Reads long as little endian.
*
* @param stream
* Data source
* @return long value
* @throws IOException
* read error, or eof is reached before long is completed
*/
public static long readUINT64(InputStream stream) throws IOException {
long result = 0;
for (int i = 0; i <= 56; i += 8) {
// Warning, always cast to long here. Otherwise it will be
// shifted as int, which may produce a negative value, which will
// then be extended to long and assign the long variable a negative
// value.
result |= (long) stream.read() << i;
}
return result;
}
/**
* This method reads a UTF-16 encoded String, beginning with a 16-bit value
* representing the number of bytes needed. The String is terminated with as
* 16-bit ZERO. <br>
*
* @param stream
* Input source
* @return read String.
* @throws IOException
* read errors.
*/
public static String readUTF16LEStr(InputStream stream) throws IOException {
int strLen = readUINT16(stream);
byte[] buf = new byte[strLen];
int read = stream.read(buf);
if (read == strLen || (strLen == 0 && read == -1)) {
/*
* Check on zero termination
*/
if (buf.length >= 2) {
if (buf[buf.length - 1] == 0 && buf[buf.length - 2] == 0) {
byte[] copy = new byte[buf.length - 2];
System.arraycopy(buf, 0, copy, 0, buf.length - 2);
buf = copy;
}
}
return new String(buf, AsfHeader.ASF_CHARSET.name());
}
throw new IllegalStateException(
"Invalid Data for current interpretation"); //$NON-NLS-1$
}
/**
* Writes the given value as UINT16 into the stream.
*
* @param number
* value to write.
* @param out
* stream to write into.
* @throws IOException
* On I/O errors
*/
public static void writeUINT16(int number, OutputStream out)
throws IOException {
if (number < 0) {
throw new IllegalArgumentException("positive value expected."); //$NON-NLS-1$
}
byte[] toWrite = new byte[2];
for (int i = 0; i <= 8; i += 8) {
toWrite[i / 8] = (byte) ((number >> i) & 0xFF);
}
out.write(toWrite);
}
/**
* Writes the given value as UINT32 into the stream.
*
* @param number
* value to write.
* @param out
* stream to write into.
* @throws IOException
* On I/O errors
*/
public static void writeUINT32(long number, OutputStream out)
throws IOException {
if (number < 0) {
throw new IllegalArgumentException("positive value expected."); //$NON-NLS-1$
}
byte[] toWrite = new byte[4];
for (int i = 0; i <= 24; i += 8) {
toWrite[i / 8] = (byte) ((number >> i) & 0xFF);
}
out.write(toWrite);
}
/**
* Writes the given value as UINT64 into the stream.
*
* @param number
* value to write.
* @param out
* stream to write into.
* @throws IOException
* On I/O errors
*/
public static void writeUINT64(long number, OutputStream out)
throws IOException {
if (number < 0) {
throw new IllegalArgumentException("positive value expected."); //$NON-NLS-1$
}
byte[] toWrite = new byte[8];
for (int i = 0; i <= 56; i += 8) {
toWrite[i / 8] = (byte) ((number >> i) & 0xFF);
}
out.write(toWrite);
}
} |
