/**
* Check if the digital object conforms to this Module's internal signature information.
*
* <p>HTML is one of the most ill-defined of any open formats, so checking a "signature" really
* means using some heuristics. The only required tag is TITLE, but that could occur well into the
* file. So we look for any of three strings -- taking into account case-independence and white
* space -- within the first sigBytes bytes, and call that a signature check.
*
* @param file A File object for the object being parsed
* @param stream An InputStream, positioned at its beginning, which is generated from the object
* to be parsed
* @param info A fresh RepInfo object which will be modified to reflect the results of the test
*/
public void checkSignatures(File file, InputStream stream, RepInfo info) throws IOException {
info.setFormat(_format[0]);
info.setMimeType(_mimeType[0]);
info.setModule(this);
char[][] sigtext = new char[3][];
sigtext[0] = "<!DOCTYPE HTML".toCharArray();
sigtext[1] = "<HTML".toCharArray();
sigtext[2] = "<TITLE".toCharArray();
int[] sigstate = {0, 0, 0};
JhoveBase jb = getBase();
int sigBytes = jb.getSigBytes();
int bytesRead = 0;
boolean eof = false;
DataInputStream dstream = new DataInputStream(stream);
while (!eof && bytesRead < sigBytes) {
try {
int ch = readUnsignedByte(dstream, this);
char chr = Character.toUpperCase((char) ch);
++bytesRead;
if (Character.isWhitespace(chr)) {
continue; // ignore all whitespace
}
for (int i = 0; i < 3; i++) {
int ss = sigstate[i];
char[] st = sigtext[i];
if (chr == st[ss]) {
++sigstate[i];
if (sigstate[i] == st.length) {
// One of the sig texts matches!
info.setSigMatch(_name);
return;
}
} else sigstate[i] = 0;
}
} catch (EOFException e) {
eof = true;
}
}
// If we fall through, there was no sig match
info.setWellFormed(false);
return;
}
/**
* Parse the content of a purported HTML stream digital object and store the results in RepInfo.
*
* @param stream An InputStream, positioned at its beginning, which is generated from the object
* to be parsed. If multiple calls to <code>parse</code> are made on the basis of a nonzero
* value being returned, a new InputStream must be provided each time.
* @param info A fresh (on the first call) RepInfo object which will be modified to reflect the
* results of the parsing If multiple calls to <code>parse</code> are made on the basis of a
* nonzero value being returned, the same RepInfo object should be passed with each call.
* @param parseIndex Must be 0 in first call to <code>parse</code>. If <code>parse</code> returns
* a nonzero value, it must be called again with <code>parseIndex</code> equal to that return
* value.
*/
public int parse(InputStream stream, RepInfo info, int parseIndex) throws IOException {
if (parseIndex != 0) {
// Coming in with parseIndex = 1 indicates that we've determined
// this is XHTML; so we invoke the XML module to parse it.
// If parseIndex is 100, this is the first invocation of the
// XML module, so we call it with 0; otherwise we call it with
// the value of parseIndex.
if (isXmlAvailable()) {
edu.harvard.hul.ois.jhove.module.XmlModule xmlMod =
new edu.harvard.hul.ois.jhove.module.XmlModule();
if (parseIndex == 100) {
parseIndex = 0;
}
xmlMod.setApp(_app);
xmlMod.setBase(_je);
xmlMod.setDefaultParams(_defaultParams);
try {
xmlMod.applyDefaultParams();
} catch (Exception e) {
// really shouldn't happen
}
xmlMod.setXhtmlDoctype(_doctype);
return xmlMod.parse(stream, info, parseIndex);
} else {
// The XML module shouldn't be missing from any installation,
// but someone who really wanted to could remove it. In
// that case, you deserve what you get.
info.setMessage(new ErrorMessage("XML-HUL module required to validate XHTML documents"));
info.setWellFormed(false); // Treat it as completely wrong
return 0;
}
} else {
/* parseIndex = 0, first call only */
_doctype = null;
}
// Test if textMD is to be generated
if (_defaultParams != null) {
Iterator iter = _defaultParams.iterator();
while (iter.hasNext()) {
String param = (String) iter.next();
if (param.toLowerCase().equals("withtextmd=true")) {
_withTextMD = true;
}
}
}
initParse();
info.setFormat(_format[0]);
info.setMimeType(_mimeType[0]);
info.setModule(this);
if (_textMD == null || parseIndex == 0) {
_textMD = new TextMDMetadata();
}
/* We may have already done the checksums while converting a
temporary file. */
Checksummer ckSummer = null;
if (_je != null && _je.getChecksumFlag() && info.getChecksum().size() == 0) {
ckSummer = new Checksummer();
_cstream = new ChecksumInputStream(stream, ckSummer);
_dstream = getBufferedDataStream(_cstream, _je != null ? _je.getBufferSize() : 0);
} else {
_dstream = getBufferedDataStream(stream, _je != null ? _je.getBufferSize() : 0);
}
ParseHtml parser = null;
HtmlMetadata metadata = null;
HtmlCharStream cstream = null;
try {
cstream = new HtmlCharStream(_dstream, "ISO-8859-1");
parser = new ParseHtml(cstream);
} catch (UnsupportedEncodingException e) {
info.setMessage(new ErrorMessage("Internal error: " + e.getMessage()));
info.setWellFormed(false);
return 0; // shouldn't happen!
}
int type = 0;
try {
List elements = parser.HtmlDoc();
if (elements.isEmpty()) {
// Consider an empty document bad
info.setWellFormed(false);
info.setMessage(new ErrorMessage("Document is empty"));
return 0;
}
type = checkDoctype(elements);
if (type < 0) {
info.setWellFormed(false);
info.setMessage(new ErrorMessage("DOCTYPE is not HTML"));
return 0;
}
/* Check if there is at least one html, head, body or title tag.
* A plain text document
* might be interpreted as a single PCDATA, which is in some
* ethereal sense well-formed HTML, but it's pointless to consider
* it such. It might also use angle brackets as a text delimiter,
* and that shouldn't count as HTML either. */
boolean hasElements = false;
Iterator iter = elements.iterator();
while (iter.hasNext()) {
Object o = iter.next();
if (o instanceof JHOpenTag) {
String name = ((JHOpenTag) o).getName();
if ("html".equals(name)
|| "head".equals(name)
|| "body".equals(name)
|| "title".equals(name)) {
hasElements = true;
}
break;
}
}
if (!hasElements) {
info.setMessage(new ErrorMessage("Document contains no html, head, body or title tags"));
info.setWellFormed(false);
return 0;
}
// CRLF from HtmlCharStream ...
String lineEnd = cstream.getKindOfLineEnd();
if (lineEnd == null) {
info.setMessage(new InfoMessage("Not able to determine type of end of line"));
_textMD.setLinebreak(TextMDMetadata.NILL);
} else if (lineEnd.equalsIgnoreCase("CR")) {
_textMD.setLinebreak(TextMDMetadata.LINEBREAK_CR);
} else if (lineEnd.equalsIgnoreCase("LF")) {
_textMD.setLinebreak(TextMDMetadata.LINEBREAK_LF);
} else if (lineEnd.equalsIgnoreCase("CRLF")) {
_textMD.setLinebreak(TextMDMetadata.LINEBREAK_CRLF);
}
if (type == 0) {
/* If we can't find a doctype, it still might be XHTML
* if the elements start with an XML declaration and
* the root element is "html" */
switch (seemsToBeXHTML(elements)) {
case 0: // Not XML
break; // fall through
case 1: // XML but not HTML
info.setMessage(
new ErrorMessage(
"Document has XML declaration but no DOCTYPE; "
+ "probably XML rather than HTML"));
info.setWellFormed(false);
return 0;
case 2: // probably XHTML
return 100;
}
info.setMessage(
new ErrorMessage(
"Unrecognized or missing DOCTYPE declaration; "
+ "validation continuing as HTML 3.2"));
info.setValid(false);
// But keep going
}
HtmlDocDesc docDesc = null;
switch (type) {
case HTML_3_2:
default:
docDesc = new Html3_2DocDesc();
_textMD.setMarkup_basis("HTML");
_textMD.setMarkup_basis_version("3.2");
break;
case HTML_4_0_FRAMESET:
docDesc = new Html4_0FrameDocDesc();
_textMD.setMarkup_basis("HTML");
_textMD.setMarkup_basis_version("4.0");
break;
case HTML_4_0_TRANSITIONAL:
docDesc = new Html4_0TransDocDesc();
_textMD.setMarkup_basis("HTML");
_textMD.setMarkup_basis_version("4.0");
break;
case HTML_4_0_STRICT:
docDesc = new Html4_0StrictDocDesc();
_textMD.setMarkup_basis("HTML");
_textMD.setMarkup_basis_version("4.0");
break;
case HTML_4_01_FRAMESET:
docDesc = new Html4_01FrameDocDesc();
_textMD.setMarkup_basis("HTML");
_textMD.setMarkup_basis_version("4.01");
break;
case HTML_4_01_TRANSITIONAL:
docDesc = new Html4_01TransDocDesc();
_textMD.setMarkup_basis("HTML");
_textMD.setMarkup_basis_version("4.01");
break;
case HTML_4_01_STRICT:
docDesc = new Html4_01StrictDocDesc();
_textMD.setMarkup_basis("HTML");
_textMD.setMarkup_basis_version("4.01");
break;
case XHTML_1_0_STRICT:
case XHTML_1_0_TRANSITIONAL:
case XHTML_1_0_FRAMESET:
case XHTML_1_1:
// Force a second call to parse as XML. 100 is a
// magic code for the first XML call.
return 100;
}
_textMD.setMarkup_language(_doctype);
if (docDesc == null) {
info.setMessage(
new InfoMessage(
"Code for appropriate HTML version not available yet:" + "substituting HTML 3.2"));
docDesc = new Html3_2DocDesc();
}
docDesc.validate(elements, info);
metadata = docDesc.getMetadata();
// Try to get the charset from the meta Content
if (metadata.getCharset() != null) {
_textMD.setCharset(metadata.getCharset());
} else {
_textMD.setCharset(TextMDMetadata.CHARSET_ISO8859_1);
}
String textMDEncoding = _textMD.getCharset();
if (textMDEncoding.indexOf("UTF") != -1) {
_textMD.setByte_order(
_bigEndian ? TextMDMetadata.BYTE_ORDER_BIG : TextMDMetadata.BYTE_ORDER_LITTLE);
_textMD.setByte_size("8");
_textMD.setCharacter_size("variable");
} else {
_textMD.setByte_order(
_bigEndian ? TextMDMetadata.BYTE_ORDER_BIG : TextMDMetadata.BYTE_ORDER_LITTLE);
_textMD.setByte_size("8");
_textMD.setCharacter_size("1");
}
} catch (ParseException e) {
Token t = e.currentToken;
info.setMessage(
new ErrorMessage("Parse error", "Line = " + t.beginLine + ", column = " + t.beginColumn));
info.setWellFormed(false);
} catch (TokenMgrError f) {
info.setMessage(new ErrorMessage("TokenMgrError: " + f.getLocalizedMessage()));
info.setWellFormed(false);
}
if (info.getWellFormed() == RepInfo.FALSE) {
return 0;
}
if (type != 0) {
if (profileNames[type] != null) {
info.setProfile(profileNames[type]);
}
info.setVersion(versionNames[type]);
}
if (metadata != null) {
Property property = metadata.toProperty(_withTextMD ? _textMD : null);
if (property != null) {
info.setProperty(property);
}
}
if (ckSummer != null) {
info.setSize(_cstream.getNBytes());
info.setChecksum(new Checksum(ckSummer.getCRC32(), ChecksumType.CRC32));
String value = ckSummer.getMD5();
if (value != null) {
info.setChecksum(new Checksum(value, ChecksumType.MD5));
}
if ((value = ckSummer.getSHA1()) != null) {
info.setChecksum(new Checksum(value, ChecksumType.SHA1));
}
}
return 0;
}
