All Downloads are FREE. Search and download functionalities are using the official Maven repository.

org.opencms.util.CmsHtml2TextConverter Maven / Gradle / Ivy

Go to download

OpenCms is an enterprise-ready, easy to use website content management system based on Java and XML technology. Offering a complete set of features, OpenCms helps content managers worldwide to create and maintain beautiful websites fast and efficiently.

There is a newer version: 18.0
Show newest version

package org.opencms.util;

import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;

import org.htmlparser.Tag;
import org.htmlparser.Text;
import org.htmlparser.util.Translate;

/**
 * Extracts the HTML page content.

*/ public class CmsHtml2TextConverter extends CmsHtmlParser { /** Indicated to append or store the next line breaks. */ private boolean m_appendBr; /** Map of stored attributes that must be written to the output when the tag closes. */ private Map m_attributeMap; /** The last appended line break count. */ private int m_brCount; /** The current indentation. */ private int m_indent; /** The current line length. */ private int m_lineLength; /** The marker String (for headlines, bullets etc.). */ private String m_marker; /** The maximum line length. */ private int m_maxLineLength; /** The last stored, but not appended line break count. */ private int m_storedBrCount; /** * Creates a new instance of the html converter.

*/ public CmsHtml2TextConverter() { m_result = new StringBuffer(512); m_maxLineLength = 100; m_attributeMap = new HashMap(16); } /** * Extracts the text from the given html content, assuming the given html encoding.

* * @param html the content to extract the plain text from * @param encoding the encoding to use * * @return the text extracted from the given html content * * @throws Exception if something goes wrong */ public static String html2text(String html, String encoding) throws Exception { // create the converter instance CmsHtml2TextConverter visitor = new CmsHtml2TextConverter(); return visitor.process(html, encoding); } /** * @see org.htmlparser.visitors.NodeVisitor#visitEndTag(org.htmlparser.Tag) */ @Override public void visitEndTag(Tag tag) { m_appendBr = false; appendLinebreaks(tag, false); String attribute = m_attributeMap.remove(tag.getParent()); if (attribute != null) { appendText(attribute); } } /** * @see org.htmlparser.visitors.NodeVisitor#visitStringNode(org.htmlparser.Text) */ @Override public void visitStringNode(Text text) { appendText(text.toPlainTextString()); } /** * @see org.htmlparser.visitors.NodeVisitor#visitTag(org.htmlparser.Tag) */ @Override public void visitTag(Tag tag) { m_appendBr = true; appendLinebreaks(tag, true); if (tag.getTagName().equals("IMG")) { appendText("##IMG##"); } String href = tag.getAttribute("href"); if (CmsStringUtil.isNotEmptyOrWhitespaceOnly(href)) { appendAttribute(tag, " [" + href.trim() + "]"); } String src = tag.getAttribute("src"); if (CmsStringUtil.isNotEmptyOrWhitespaceOnly(src)) { appendAttribute(tag, " [" + src.trim() + "]"); } String title = tag.getAttribute("title"); if (CmsStringUtil.isNotEmptyOrWhitespaceOnly(title)) { appendAttribute(tag, " {" + title.trim() + "}"); } String alt = tag.getAttribute("alt"); if (CmsStringUtil.isNotEmptyOrWhitespaceOnly(alt)) { appendAttribute(tag, " {" + alt.trim() + "}"); } } /** * Appends an attribute.

* * @param tag the tag * @param text the attribute text */ private void appendAttribute(Tag tag, String text) { if (tag.getTagName().equals("IMG")) { appendText(text); } else { String current = m_attributeMap.get(tag); if (current != null) { text = current + text; } m_attributeMap.put(tag, text); } } /** * Appends an indentation.

*/ private void appendIndentation() { if (m_lineLength <= m_indent) { int len = (m_marker != null) ? m_indent - (m_marker.length() + 1) : m_indent; for (int i = 0; i < len; i++) { m_result.append(' '); } if (m_marker != null) { m_result.append(m_marker); m_result.append(' '); m_marker = null; } } } /** * Appends a line break.

* * @param count the number of lines */ private void appendLinebreak(int count) { appendLinebreak(count, false); } /** * Appends line breaks.

* * @param count the number of line breaks * @param force if the line break should be forced */ private void appendLinebreak(int count, boolean force) { if (m_appendBr) { if (m_storedBrCount > count) { count = m_storedBrCount; } m_storedBrCount = 0; if (force) { m_brCount = 0; } while (m_brCount < count) { m_result.append("\r\n"); m_brCount++; } m_lineLength = m_indent; } else { while (m_storedBrCount < count) { m_storedBrCount++; } } } /** * Appends line breaks.

* * @param tag the tag * @param open the open flag */ private void appendLinebreaks(Tag tag, boolean open) { String name = tag.getTagName(); int pos = TAG_LIST.indexOf(name); switch (pos) { case 0: // H1 setMarker("=", open); setIndentation(2, open); appendLinebreak(2); break; case 1: // H2 setMarker("==", open); setIndentation(3, open); appendLinebreak(2); break; case 2: // H3 setMarker("===", open); setIndentation(4, open); appendLinebreak(2); break; case 3: // H4 setMarker("====", open); setIndentation(5, open); appendLinebreak(2); break; case 4: // H5 setMarker("=====", open); setIndentation(6, open); appendLinebreak(2); break; case 5: // H6 setMarker("=======", open); setIndentation(7, open); appendLinebreak(2); break; case 6: // P case 7: // DIV appendLinebreak(2); break; case 8: // SPAN break; case 9: // BR appendLinebreak(1, true); break; case 10: // OL case 11: // UL appendLinebreak(2); break; case 12: // LI setMarker("*", open); setIndentation(5, open); appendLinebreak(1); break; case 13: // TABLE setIndentation(5, open); appendLinebreak(2); if (open) { appendLinebreak(1); appendText("-----"); appendLinebreak(1); } break; case 14: // TD setMarker("--", open); appendLinebreak(2); break; case 15: // TR if (!open) { appendLinebreak(1); appendText("-----"); appendLinebreak(1); } break; case 16: // TH case 17: // THEAD case 18: // TBODY case 19: // TFOOT appendLinebreak(1); break; default: // unknown tag (ignore) } } /** * Appends text.

* * @param text the text */ private void appendText(String text) { if (CmsStringUtil.isNotEmptyOrWhitespaceOnly(text)) { text = Translate.decode(text); text = collapse(text); } if (CmsStringUtil.isNotEmptyOrWhitespaceOnly(text)) { if (m_storedBrCount > 0) { m_appendBr = true; appendLinebreak(m_storedBrCount); } appendIndentation(); m_brCount = 0; List wordList = CmsStringUtil.splitAsList(text, ' '); Iterator i = wordList.iterator(); while (i.hasNext()) { String word = i.next(); boolean hasNbsp = ((word.charAt(0) == 160) || (word.charAt(word.length() - 1) == 160)); if ((word.length() + 1 + m_lineLength) > m_maxLineLength) { m_appendBr = true; appendLinebreak(1); appendIndentation(); m_brCount = 0; } else { if (!hasNbsp && (m_lineLength > m_indent) && (m_result.charAt(m_result.length() - 1) != 160) && (m_result.charAt(m_result.length() - 1) != 32)) { m_result.append(' '); m_lineLength++; } } m_result.append(word); m_lineLength += word.length(); } } } /** * Sets the indentation.

* * @param length the indentation length * @param open if the indentation should be added or reduced */ private void setIndentation(int length, boolean open) { if (open) { m_indent += length; } else { m_indent -= length; if (m_indent < 0) { m_indent = 0; } } } /** * Sets the marker.

* * @param marker the marker * @param open if the marker should be added */ private void setMarker(String marker, boolean open) { if (open) { m_marker = marker; } } }





© 2015 - 2024 Weber Informatics LLC | Privacy Policy