org.apache.poi.hpsf.VariantSupport Maven / Gradle / Ivy
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package org.apache.poi.hpsf;
import java.io.IOException;
import java.io.OutputStream;
import java.io.UnsupportedEncodingException;
import java.util.Date;
import java.util.LinkedList;
import java.util.List;
import org.apache.poi.util.LittleEndian;
import org.apache.poi.util.LittleEndianConsts;
/**
* Supports reading and writing of variant data.
*
* FIXME (3): Reading and writing should be made more
* uniform than it is now. The following items should be resolved:
*
*
*
* Reading requires a length parameter that is 4 byte greater than the
* actual data, because the variant type field is included.
Reading reads from a byte array while writing writes to an byte array
* output stream.
*
* @author Rainer Klute <[email protected]>
*/
public class VariantSupport extends Variant
{
private static boolean logUnsupportedTypes = false;
/**
* Specifies whether warnings about unsupported variant types are to be
* written to System.err or not.
*
* @param logUnsupportedTypes If true warnings will be written,
* if false they won't.
*/
public static void setLogUnsupportedTypes(final boolean logUnsupportedTypes)
{
VariantSupport.logUnsupportedTypes = logUnsupportedTypes;
}
/**
* Checks whether logging of unsupported variant types warning is turned
* on or off.
*
* @return true if logging is turned on, else
* false.
*/
public static boolean isLogUnsupportedTypes()
{
return logUnsupportedTypes;
}
/**
* Keeps a list of the variant types an "unsupported" message has already
* been issued for.
*/
protected static List unsupportedMessage;
/**
* Writes a warning to System.err that a variant type is
* unsupported by HPSF. Such a warning is written only once for each variant
* type. Log messages can be turned on or off by
*
* @param ex The exception to log
*/
protected static void writeUnsupportedTypeMessage
(final UnsupportedVariantTypeException ex)
{
if (isLogUnsupportedTypes())
{
if (unsupportedMessage == null)
unsupportedMessage = new LinkedList();
Long vt = Long.valueOf(ex.getVariantType());
if (!unsupportedMessage.contains(vt))
{
System.err.println(ex.getMessage());
unsupportedMessage.add(vt);
}
}
}
/**
* HPSF is able to read these {@link Variant} types.
*/
final static public int[] SUPPORTED_TYPES = { Variant.VT_EMPTY,
Variant.VT_I2, Variant.VT_I4, Variant.VT_I8, Variant.VT_R8,
Variant.VT_FILETIME, Variant.VT_LPSTR, Variant.VT_LPWSTR,
Variant.VT_CF, Variant.VT_BOOL };
/**
* Checks whether HPSF supports the specified variant type. Unsupported
* types should be implemented included in the {@link #SUPPORTED_TYPES}
* array.
*
* @see Variant
* @param variantType the variant type to check
* @return true if HPFS supports this type, else
* false
*/
public boolean isSupportedType(final int variantType)
{
for (int i = 0; i < SUPPORTED_TYPES.length; i++)
if (variantType == SUPPORTED_TYPES[i])
return true;
return false;
}
/**
* Reads a variant type from a byte array.
*
* @param src The byte array
* @param offset The offset in the byte array where the variant starts
* @param length The length of the variant including the variant type field
* @param type The variant type to read
* @param codepage The codepage to use for non-wide strings
* @return A Java object that corresponds best to the variant field. For
* example, a VT_I4 is returned as a {@link Long}, a VT_LPSTR as a
* {@link String}.
* @exception ReadingNotSupportedException if a property is to be written
* who's variant type HPSF does not yet support
* @exception UnsupportedEncodingException if the specified codepage is not
* supported.
* @see Variant
*/
public static Object read(final byte[] src, final int offset,
final int length, final long type,
final int codepage)
throws ReadingNotSupportedException, UnsupportedEncodingException
{
Object value;
int o1 = offset;
int l1 = length - LittleEndian.INT_SIZE;
long lType = type;
/* Instead of trying to read 8-bit characters from a Unicode string,
* read 16-bit characters. */
if (codepage == Constants.CP_UNICODE && type == Variant.VT_LPSTR)
lType = Variant.VT_LPWSTR;
switch ((int) lType)
{
case Variant.VT_EMPTY:
{
value = null;
break;
}
case Variant.VT_I2:
{
/*
* Read a short. In Java it is represented as an
* Integer object.
*/
value = Integer.valueOf(LittleEndian.getShort(src, o1));
break;
}
case Variant.VT_I4:
{
/*
* Read a word. In Java it is represented as an
* Integer object.
*/
value = Integer.valueOf(LittleEndian.getInt(src, o1));
break;
}
case Variant.VT_I8:
{
/*
* Read a double word. In Java it is represented as a
* Long object.
*/
value = Long.valueOf(LittleEndian.getLong(src, o1));
break;
}
case Variant.VT_R8:
{
/*
* Read an eight-byte double value. In Java it is represented as
* a Double object.
*/
value = new Double(LittleEndian.getDouble(src, o1));
break;
}
case Variant.VT_FILETIME:
{
/*
* Read a FILETIME object. In Java it is represented
* as a Date object.
*/
final long low = LittleEndian.getUInt(src, o1);
o1 += LittleEndian.INT_SIZE;
final long high = LittleEndian.getUInt(src, o1);
value = Util.filetimeToDate((int) high, (int) low);
break;
}
case Variant.VT_LPSTR:
{
/*
* Read a byte string. In Java it is represented as a
* String object. The 0x00 bytes at the end must be
* stripped.
*/
final int first = o1 + LittleEndian.INT_SIZE;
long last = first + LittleEndian.getUInt(src, o1) - 1;
o1 += LittleEndian.INT_SIZE;
while (src[(int) last] == 0 && first <= last)
last--;
final int l = (int) (last - first + 1);
value = codepage != -1 ?
new String(src, first, l,
codepageToEncoding(codepage)) :
new String(src, first, l);
break;
}
case Variant.VT_LPWSTR:
{
/*
* Read a Unicode string. In Java it is represented as
* a String object. The 0x00 bytes at the end must be
* stripped.
*/
final int first = o1 + LittleEndian.INT_SIZE;
long last = first + LittleEndian.getUInt(src, o1) - 1;
long l = last - first;
o1 += LittleEndian.INT_SIZE;
StringBuffer b = new StringBuffer((int) (last - first));
for (int i = 0; i <= l; i++)
{
final int i1 = o1 + (i * 2);
final int i2 = i1 + 1;
final int high = src[i2] << 8;
final int low = src[i1] & 0x00ff;
final char c = (char) (high | low);
b.append(c);
}
/* Strip 0x00 characters from the end of the string: */
while (b.length() > 0 && b.charAt(b.length() - 1) == 0x00)
b.setLength(b.length() - 1);
value = b.toString();
break;
}
case Variant.VT_CF:
{
if(l1 < 0) {
/**
* YK: reading the ClipboardData packet (VT_CF) is not quite correct.
* The size of the data is determined by the first four bytes of the packet
* while the current implementation calculates it in the Section constructor.
* Test files in Bugzilla 42726 and 45583 clearly show that this approach does not always work.
* The workaround below attempts to gracefully handle such cases instead of throwing exceptions.
*
* August 20, 2009
*/
l1 = LittleEndian.getInt(src, o1); o1 += LittleEndian.INT_SIZE;
}
final byte[] v = new byte[l1];
System.arraycopy(src, o1, v, 0, v.length);
value = v;
break;
}
case Variant.VT_BOOL:
{
/*
* The first four bytes in src, from src[offset] to
* src[offset + 3] contain the DWord for VT_BOOL, so
* skip it, we don't need it.
*/
// final int first = offset + LittleEndian.INT_SIZE;
long bool = LittleEndian.getUInt(src, o1);
if (bool != 0)
value = Boolean.TRUE;
else
value = Boolean.FALSE;
break;
}
default:
{
final byte[] v = new byte[l1];
for (int i = 0; i < l1; i++)
v[i] = src[(o1 + i)];
throw new ReadingNotSupportedException(type, v);
}
}
return value;
}
/**
* Turns a codepage number into the equivalent character encoding's
* name.
*
* @param codepage The codepage number
*
* @return The character encoding's name. If the codepage number is 65001,
* the encoding name is "UTF-8". All other positive numbers are mapped to
* "cp" followed by the number, e.g. if the codepage number is 1252 the
* returned character encoding name will be "cp1252".
*
* @exception UnsupportedEncodingException if the specified codepage is
* less than zero.
*/
public static String codepageToEncoding(final int codepage)
throws UnsupportedEncodingException
{
if (codepage <= 0)
throw new UnsupportedEncodingException
("Codepage number may not be " + codepage);
switch (codepage)
{
case Constants.CP_UTF16:
return "UTF-16";
case Constants.CP_UTF16_BE:
return "UTF-16BE";
case Constants.CP_UTF8:
return "UTF-8";
case Constants.CP_037:
return "cp037";
case Constants.CP_GBK:
return "GBK";
case Constants.CP_MS949:
return "ms949";
case Constants.CP_WINDOWS_1250:
return "windows-1250";
case Constants.CP_WINDOWS_1251:
return "windows-1251";
case Constants.CP_WINDOWS_1252:
return "windows-1252";
case Constants.CP_WINDOWS_1253:
return "windows-1253";
case Constants.CP_WINDOWS_1254:
return "windows-1254";
case Constants.CP_WINDOWS_1255:
return "windows-1255";
case Constants.CP_WINDOWS_1256:
return "windows-1256";
case Constants.CP_WINDOWS_1257:
return "windows-1257";
case Constants.CP_WINDOWS_1258:
return "windows-1258";
case Constants.CP_JOHAB:
return "johab";
case Constants.CP_MAC_ROMAN:
return "MacRoman";
case Constants.CP_MAC_JAPAN:
return "SJIS";
case Constants.CP_MAC_CHINESE_TRADITIONAL:
return "Big5";
case Constants.CP_MAC_KOREAN:
return "EUC-KR";
case Constants.CP_MAC_ARABIC:
return "MacArabic";
case Constants.CP_MAC_HEBREW:
return "MacHebrew";
case Constants.CP_MAC_GREEK:
return "MacGreek";
case Constants.CP_MAC_CYRILLIC:
return "MacCyrillic";
case Constants.CP_MAC_CHINESE_SIMPLE:
return "EUC_CN";
case Constants.CP_MAC_ROMANIA:
return "MacRomania";
case Constants.CP_MAC_UKRAINE:
return "MacUkraine";
case Constants.CP_MAC_THAI:
return "MacThai";
case Constants.CP_MAC_CENTRAL_EUROPE:
return "MacCentralEurope";
case Constants.CP_MAC_ICELAND:
return "MacIceland";
case Constants.CP_MAC_TURKISH:
return "MacTurkish";
case Constants.CP_MAC_CROATIAN:
return "MacCroatian";
case Constants.CP_US_ACSII:
case Constants.CP_US_ASCII2:
return "US-ASCII";
case Constants.CP_KOI8_R:
return "KOI8-R";
case Constants.CP_ISO_8859_1:
return "ISO-8859-1";
case Constants.CP_ISO_8859_2:
return "ISO-8859-2";
case Constants.CP_ISO_8859_3:
return "ISO-8859-3";
case Constants.CP_ISO_8859_4:
return "ISO-8859-4";
case Constants.CP_ISO_8859_5:
return "ISO-8859-5";
case Constants.CP_ISO_8859_6:
return "ISO-8859-6";
case Constants.CP_ISO_8859_7:
return "ISO-8859-7";
case Constants.CP_ISO_8859_8:
return "ISO-8859-8";
case Constants.CP_ISO_8859_9:
return "ISO-8859-9";
case Constants.CP_ISO_2022_JP1:
case Constants.CP_ISO_2022_JP2:
case Constants.CP_ISO_2022_JP3:
return "ISO-2022-JP";
case Constants.CP_ISO_2022_KR:
return "ISO-2022-KR";
case Constants.CP_EUC_JP:
return "EUC-JP";
case Constants.CP_EUC_KR:
return "EUC-KR";
case Constants.CP_GB2312:
return "GB2312";
case Constants.CP_GB18030:
return "GB18030";
case Constants.CP_SJIS:
return "SJIS";
default:
return "cp" + codepage;
}
}
/**
* Writes a variant value to an output stream. This method ensures that
* always a multiple of 4 bytes is written.
*
* If the codepage is UTF-16, which is encouraged, strings
* must always be written as {@link Variant#VT_LPWSTR}
* strings, not as {@link Variant#VT_LPSTR} strings. This method ensure this
* by converting strings appropriately, if needed.
*
* @param out The stream to write the value to.
* @param type The variant's type.
* @param value The variant's value.
* @param codepage The codepage to use to write non-wide strings
* @return The number of entities that have been written. In many cases an
* "entity" is a byte but this is not always the case.
* @exception IOException if an I/O exceptions occurs
* @exception WritingNotSupportedException if a property is to be written
* who's variant type HPSF does not yet support
*/
public static int write(final OutputStream out, final long type,
final Object value, final int codepage)
throws IOException, WritingNotSupportedException
{
int length = 0;
switch ((int) type)
{
case Variant.VT_BOOL:
{
int trueOrFalse;
if (((Boolean) value).booleanValue())
trueOrFalse = 1;
else
trueOrFalse = 0;
length = TypeWriter.writeUIntToStream(out, trueOrFalse);
break;
}
case Variant.VT_LPSTR:
{
final byte[] bytes =
(codepage == -1 ?
((String) value).getBytes() :
((String) value).getBytes(codepageToEncoding(codepage)));
length = TypeWriter.writeUIntToStream(out, bytes.length + 1);
final byte[] b = new byte[bytes.length + 1];
System.arraycopy(bytes, 0, b, 0, bytes.length);
b[b.length - 1] = 0x00;
out.write(b);
length += b.length;
break;
}
case Variant.VT_LPWSTR:
{
final int nrOfChars = ((String) value).length() + 1;
length += TypeWriter.writeUIntToStream(out, nrOfChars);
char[] s = Util.pad4((String) value);
for (int i = 0; i < s.length; i++)
{
final int high = ((s[i] & 0x0000ff00) >> 8);
final int low = (s[i] & 0x000000ff);
final byte highb = (byte) high;
final byte lowb = (byte) low;
out.write(lowb);
out.write(highb);
length += 2;
}
out.write(0x00);
out.write(0x00);
length += 2;
break;
}
case Variant.VT_CF:
{
final byte[] b = (byte[]) value;
out.write(b);
length = b.length;
break;
}
case Variant.VT_EMPTY:
{
TypeWriter.writeUIntToStream(out, Variant.VT_EMPTY);
length = LittleEndianConsts.INT_SIZE;
break;
}
case Variant.VT_I2:
{
TypeWriter.writeToStream(out, ((Integer) value).shortValue());
length = LittleEndianConsts.SHORT_SIZE;
break;
}
case Variant.VT_I4:
{
if (!(value instanceof Integer))
{
throw new ClassCastException("Could not cast an object to "
+ Integer.class.toString() + ": "
+ value.getClass().toString() + ", "
+ value.toString());
}
length += TypeWriter.writeToStream(out,
((Integer) value).intValue());
break;
}
case Variant.VT_I8:
{
TypeWriter.writeToStream(out, ((Long) value).longValue());
length = LittleEndianConsts.LONG_SIZE;
break;
}
case Variant.VT_R8:
{
length += TypeWriter.writeToStream(out,
((Double) value).doubleValue());
break;
}
case Variant.VT_FILETIME:
{
long filetime = Util.dateToFileTime((Date) value);
int high = (int) ((filetime >> 32) & 0x00000000FFFFFFFFL);
int low = (int) (filetime & 0x00000000FFFFFFFFL);
length += TypeWriter.writeUIntToStream
(out, 0x0000000FFFFFFFFL & low);
length += TypeWriter.writeUIntToStream
(out, 0x0000000FFFFFFFFL & high);
break;
}
default:
{
/* The variant type is not supported yet. However, if the value
* is a byte array we can write it nevertheless. */
if (value instanceof byte[])
{
final byte[] b = (byte[]) value;
out.write(b);
length = b.length;
writeUnsupportedTypeMessage
(new WritingNotSupportedException(type, value));
}
else
throw new WritingNotSupportedException(type, value);
break;
}
}
return length;
}
}