/** * Add a text object to the tree (leaf). May either be pure whitespace or may contain characters. */ private void AddTextElement(String str, ITag tag) { try { if (!str.isEmpty()) { tag.Add(textFactory.Create(str)); } } catch (NotImplementedException e) { e.printStackTrace(); } }
/** * Build the HTML composite tree. * * @param buffer - File text from which to build the tree. * @param root - Root node of the tree. * @throws HtmlParseException */ private void ParseHtml(StringBuffer buffer, ITag root) throws HtmlParseException { int startIndex = 0; // Iterate as long as there are children while (true) { int startTagStartIndex = 0; int startTagEndIndex = 0; int endTagStartIndex = 0; int endTagEndIndex = 0; // Find the beginning of the next start tag ------------------------ startTagStartIndex = buffer.indexOf(START_TAG_START, startIndex); // This is the base case. if (startTagStartIndex < 0) { AddTextElement(buffer.substring(startIndex), root); return; } // Find the end of the next start tag ------------------------------ startTagEndIndex = buffer.indexOf(TAG_END, startTagStartIndex); if (startTagEndIndex < 0) { throw new HtmlParseException("No '>' found for opening tag."); } String startTag = buffer.substring(startTagStartIndex + 1, startTagEndIndex); String tagname = startTag.replaceAll("\\s+$", ""); // Find the beginning of the corresponding end tag ----------------- endTagStartIndex = buffer.indexOf(END_TAG_START + startTag.trim(), startTagEndIndex); if (endTagStartIndex < 0) { throw new HtmlParseException("No '</' found for closing tag."); } // Find the corresponding end tag ---------------------------------- endTagEndIndex = buffer.indexOf(TAG_END, endTagStartIndex); if (endTagEndIndex < 0) { throw new HtmlParseException("No '>' found for closing tag."); } String endTag = buffer.substring(endTagStartIndex + 1, endTagEndIndex); // See if there is a string before this tag. if (startIndex != startTagStartIndex) { String str = buffer.substring(startIndex, startTagStartIndex); AddTextElement(str, root); } // Create the tag ITag tag = (ITag) factory.Create(startTag, endTag); if (tag == null) { throw new HtmlParseException("Invalid HTML tag: '" + tagname + "'"); } try { root.Add(tag); } catch (NotImplementedException e) { e.printStackTrace(); } // Make the recursive parsing call to parse below the tag String tagstring = buffer.substring(startTagEndIndex + 1, endTagStartIndex); StringBuffer subbuffer = new StringBuffer(tagstring); ParseHtml(subbuffer, tag); // Set up the starting index for the iteration startIndex = endTagEndIndex + 1; } }