/**
* Replaces an end tag with its translation, if necessary.
*
* @param tagName name of the last tag picked up.
* @param buf output buffer
* @param newLineCounter current number of newline hold in output
* @return updated current number of newline hold
*/
private static int replaceEndTag(String tagName, XStringBuilder buf, int newLineCounter) {
int newlineCounterTmp = newLineCounter;
if (tagName.equals("h1")) {
// buf.append("(T1)");
newlineCounterTmp = addNewline(newLineCounter, buf);
} else if (tagName.equals("h2")) {
// buf.append("(T2)");
newlineCounterTmp = addNewline(newLineCounter, buf);
} else if (tagName.equals("td")) {
buf.append(' ');
} else if (tagName.equals("tr")) {
newlineCounterTmp = addNewline(newLineCounter, buf);
} else if (tagName.equals("li")) {
newlineCounterTmp = addNewline(newLineCounter, buf);
} else if (tagName.equals("a")) {
buf.append(' ');
}
return newlineCounterTmp;
}
/**
* Removes all HTML element tags from a string, leaving just the character data. This method does
* <b>not</b> touch any inline HTML character entity codes. Use {@link #convertCharacterEntities
* convertCharacterEntities()} to convert HTML character entity codes.
*
* @param s the string to adjust
* @return the resulting, possibly modified, string
* @see #convertCharacterEntities
*/
public static String stripHTMLTags(String s) {
char[] ch = s.toCharArray();
boolean inElement = false;
XStringBuilder buf = new XStringBuilder();
for (int i = 0; i < ch.length; i++) {
switch (ch[i]) {
case '<':
inElement = true;
break;
case '>':
if (inElement) inElement = false;
else buf.append(ch[i]);
break;
default:
if (!inElement) buf.append(ch[i]);
break;
}
}
return buf.toString();
}
/**
* Some tag substitutions add a newline (that is the string "\r\n") in order to improve clarity of
* the translated text. Thus it may happen that long sequences of newline could appear. In order
* to avoid these long sequences the <code>addNewline</code> method adds a newline only if the
* number of the newlines already inserted is less or equal a predefined number (<code>
* NEWLINES_TO_HOLD</code>).
*
* @param newlineCounter number of newlines already inserted
* @param buf uotput buffer
* @return current number of newlines inserted
*/
private static int addNewline(int newlineCounter, XStringBuilder buf) {
if (newlineCounter <= NEWLINES_TO_HOLD) {
buf.append("\r\n");
}
return ++newlineCounter;
}
/**
* Translates a String containing html to a text.
*
* @param s html to be translated
* @return text String
*/
public static String HTMLToText(String s) {
char[] ch = s.toCharArray();
boolean inElement = false;
boolean inAttributeValue = false;
boolean isStartTag = true;
boolean isEndTag = false;
boolean isTagNameComplete = false;
boolean isNewLine = false;
int ignoreLevel = 0;
int newLineCounter = 0;
String[] tagsToExclude = {"style", "head", "!DOCTYPE"};
StringBuilder tagName = new StringBuilder();
XStringBuilder buf = new XStringBuilder();
char c = ' ';
char c_prec = ' ';
String name = null;
for (int i = 0; i < ch.length; i++) {
c = ch[i];
switch (c) {
case '<':
//
// Start of a start/end tag.
//
isNewLine = false;
inElement = true;
// By default a tag is a start tag
isStartTag = true;
isEndTag = false;
isTagNameComplete = false;
tagName = new StringBuilder();
break;
case '/':
if (inElement && c_prec == '<') {
//
// An end tag has been recognized.
//
isStartTag = false;
isEndTag = true;
} else if (inElement && c_prec != '<') {
//
// A single tag (eg: <br/>) has been recognized.
//
isEndTag = true;
} else {
//
// save the / because is in the text
//
buf.append(c);
}
break;
case '>':
//
// Checks if the '>' char occurs within am attribute value.
// If this is the case, then the end of the tag has not been
// reached.
//
if (inAttributeValue) {
break;
}
//
// End of a start/end tag has been reached
//
if (inElement) {
inElement = false;
isTagNameComplete = true;
//
// Is this tag's content to be ignored ?
//
name = tagName.toString().toLowerCase();
if (isInArray(name, tagsToExclude)) {
if (isStartTag) {
ignoreLevel++;
break;
}
if (isEndTag) {
ignoreLevel--;
break;
}
}
//
// Tag substituitions
//
if (isStartTag && !isEndTag) {
newLineCounter = replaceStartTag(name, buf, newLineCounter);
}
if (isEndTag && !isStartTag) {
newLineCounter = replaceEndTag(name, buf, newLineCounter);
}
if (isEndTag && isStartTag) {
newLineCounter = replaceSingleTag(name, buf, newLineCounter);
}
}
break;
case '\"':
if (inElement && !inAttributeValue) {
inAttributeValue = true;
break;
}
if (inElement && inAttributeValue) {
inAttributeValue = false;
break;
}
if (ignoreLevel > 0) {
break;
}
buf.append(c);
break;
case '\r':
if (!inElement && c_prec != '>') {
buf.append(' ');
}
break;
case '\n':
isNewLine = true;
break;
case 0x20: // single white space
case 0xA0: // non-breaking space character
//
// Strips any white space that follows a newline.
//
if (isNewLine) {
break;
}
default:
isNewLine = false;
if (!inElement) {
if (ignoreLevel > 0) {
break;
}
newLineCounter = 0;
//
// Content enclosed by a start and an end tag is put in
// output buffer.
//
buf.append(c);
} else {
//
// Retrieve tag name. Any tag attribute is ignored.
//
if (c != ' ' && !isTagNameComplete) {
tagName.append(ch[i]);
} else {
isTagNameComplete = true;
}
}
break;
}
c_prec = c;
}
//
// Trim any leading sequence of the following characters: '\r', '\n', ' '
//
int startIndex = 0;
for (int i = 0; i < buf.length(); i++) {
c = buf.charAt(i);
if (c == '\r' || c == '\n' || c == 0x20 || c == 0xA0) {
continue;
}
startIndex = i;
break;
}
return buf.substring(startIndex);
}
