javaxt.html.Parser Maven / Gradle / Ivy
package javaxt.html;
//******************************************************************************
//** HTML Parser
//******************************************************************************
/**
* A simple html parser used to extract blocks of html from a document.
*
******************************************************************************/
public class Parser {
private String html;
// **************************************************************************
// ** Constructor
// **************************************************************************
public Parser(String html) {
this.html = html;
}
// **************************************************************************
// ** getHTML
// **************************************************************************
public String getHTML() {
return html;
}
// **************************************************************************
// ** setHTML
// **************************************************************************
/**
* Used to reset the "scope" of the parser
*/
public void setHTML(String html) {
this.html = html;
}
// **************************************************************************
// ** getElementByID
// **************************************************************************
/**
* Returns an HTML Element with a given id. Returns null if the element was
* not found.
*/
public Element getElementByID(String id) {
return getElementByAttributes(null, "id", id);
}
// **************************************************************************
// ** getElementByTagName
// **************************************************************************
/**
* Returns an array of HTML Elements found in the HTML document with given
* tag name.
*/
public Element[] getElementsByTagName(String tagName) {
String orgHTML = html;
java.util.ArrayList elements = new java.util.ArrayList();
Element e = getElementByTagName(tagName);
while (e != null) {
elements.add(e);
int idx = html.indexOf(e.outerHTML);
String a = html.substring(0, idx);
String b = html.substring(idx + e.outerHTML.length());
html = a + b;
e = getElementByTagName(tagName);
}
html = orgHTML;
return elements.toArray(new Element[elements.size()]);
}
// **************************************************************************
// ** getElementByTagName
// **************************************************************************
/**
* Returns an array of HTML Elements found in the HTML document with given
* tag name, attribute, and attribute value (e.g. "div", "class", "hdr2").
*/
public Element[] getElements(String tagName, String attributeName, String attributeValue) {
String orgHTML = html;
java.util.ArrayList elements = new java.util.ArrayList();
Element e = getElementByAttributes(tagName, attributeName, attributeValue);
while (e != null) {
elements.add(e);
int idx = html.indexOf(e.outerHTML);
String a = html.substring(0, idx);
String b = html.substring(idx + e.outerHTML.length());
html = a + b;
e = getElementByAttributes(tagName, attributeName, attributeValue);
}
html = orgHTML;
return elements.toArray(new Element[elements.size()]);
}
// **************************************************************************
// ** getElementByTagName
// **************************************************************************
/**
* Returns the first HTML Element found in the HTML document with given tag
* name. Returns null if an element was not found.
*/
public Element getElementByTagName(String tagName) {
return getElementByAttributes(tagName, null, null);
}
// **************************************************************************
// ** getElementByAttributes
// **************************************************************************
/**
* Returns the first HTML Element found in the HTML document with given tag
* name and attribute. Returns null if an element was not found.
*/
public Element getElementByAttributes(String tagName, String attributeName, String attributeValue) {
String s = html + " ";
String c = "";
boolean concat = false;
int absStart = 0;
int absEnd = 0;
int numStartTags = 0;
int numEndTags = 0;
int outerStart = 0;
int outerEnd = 0;
StringBuffer tag = new StringBuffer();
Element el = null;
boolean insideQuote = false;
boolean insideComment = false;
for (int i = 0; i < s.length(); i++) {
c = s.substring(i, i + 1);
// If we find the start of an html element, start assembling the tag
if (c.equals("<") && !insideQuote && !insideComment) {
concat = true;
absEnd = i;
}
// Check whether we are inside or outside a quote
if (c.equals("\"")) {
if (!insideQuote)
insideQuote = true;
else
insideQuote = false;
}
// Check whether we are inside or outside a javascript or css
// comment
if (c.equals("/")) {
if (insideComment) {
insideComment = (s.substring(i - 1, i + 1).equals("*/"));
} else {
insideComment = (s.substring(i, i + 2).equals("/*"));
}
}
if (concat == true) {
tag.append(c);
}
// If we find the end of an html element, analyze the tag
if ((c.equals(">") && !insideQuote && !insideComment) && concat == true) {
concat = false;
Element Tag = new Element(tag.toString());
if (el == null) {
if (Tag.isStartTag()) {
if (tagName == null || Tag.getName().equalsIgnoreCase(tagName)) { // <--Tag
// name
// is
// null
// when
// getElementByID
if (attributeName == null
|| Tag.getAttribute(attributeName).equalsIgnoreCase(attributeValue)) { // <--Filter
// by
// attributes!
absStart = i + 1;
el = Tag;
outerStart = absStart - tag.length();
// Special case for getElementByID
if (tagName == null)
tagName = Tag.getName();
// Special case for tags that self terminate
if (Tag.isEndTag()) {
// Element.innerHTML = null;
el.outerHTML = tag.toString();
return el;
}
}
}
}
} else {
if (Tag.getName().equalsIgnoreCase(tagName)) {
if (Tag.isStartTag())
numStartTags += 1;
// if (!Tag.isStartTag()) numEndTags +=1;
if (Tag.isEndTag())
numEndTags += 1;
// This is all new!
boolean foundEnd = false;
if (Tag.isStartTag() && Tag.isEndTag()) {
foundEnd = false;
} else if (!Tag.isStartTag() && Tag.isEndTag()) {
foundEnd = (numEndTags > numStartTags);
} else {
// System.out.println(numEndTags + " vs " +
// numStartTags);
foundEnd = (numEndTags >= numStartTags);
}
if (foundEnd) { // if (numEndTags>=numStartTags){
el.innerHTML = html.substring(absStart, absEnd);
outerEnd = i + 1;
el.outerHTML = html.substring(outerStart, outerEnd);
return el;
}
}
}
// Clear tag variable for the next pass
tag = new StringBuffer();
}
}
// Last ditch effort!
if (el != null) {
if (el.getOuterHTML() == null) {
el.outerHTML = el.getTag();
}
return el;
}
return null;
}
// **************************************************************************
// ** getImageLinks
// **************************************************************************
/**
* Returns a list of links to images. The links may include relative paths.
* Use the getAbsolutePath method to resolve the relative paths to a fully
* qualified url.
*/
public String[] getImageLinks() {
java.util.ArrayList links = new java.util.ArrayList();
for (Element img : getElementsByTagName("img")) {
String src = img.getAttribute("src");
if (src.length() > 0)
links.add(src);
}
return links.toArray(new String[links.size()]);
}
// **************************************************************************
// ** stripHTMLTags
// **************************************************************************
/**
* Used to remove any html tags from a block of text
*/
public static String stripHTMLTags(String html) {
String s = html + " ";
String c = "";
boolean concat = false;
String tag = "";
for (int i = 0; i < s.length(); i++) {
c = s.substring(i, i + 1);
if (c.equals("<")) {
concat = true;
}
if (concat == true) {
tag += c;
}
if (c.equals(">") && concat == true) {
concat = false;
html = html.replace(tag, "");
// Clear tag variable for the next pass
tag = "";
}
}
// html = html.replaceAll("\\s+"," ");
return html.replace(" ", " ").trim();
}
// **************************************************************************
// ** MapPath
// **************************************************************************
/**
* Returns a fully qualified URL for a given path. Returns null if the
* function fails to resolve the path.
*
* @param relPath
* Relative path to a file (e.g. "../images/header.jpg")
* @param url
* URL that is sourcing the relPath (e.g.
* "http://acme.com/about/")
* @return Using the examples cited in the 2 parameters, return a URL
* "http://acme.com/images/header.jpg"
*/
public static String MapPath(String relPath, java.net.URL url) {
// Check if relPath is a fully qualified URL. If so, return the relPath.
try {
new java.net.URL(relPath);
return relPath;
} catch (Exception e) {
}
// Remove "./" prefix in the relPath
if (relPath.length() > 2) {
if (relPath.substring(0, 2).equals("./")) {
relPath = relPath.substring(2, relPath.length());
}
}
String[] arrRelPath = relPath.split("/");
try {
String urlBase = url.getProtocol() + "://" + url.getHost();
int port = url.getPort();
if (port > 0 && port != 80)
urlBase += ":" + url.getPort();
// Build Path
String urlPath = "";
String newPath;
if (relPath.substring(0, 1).equals("/")) {
newPath = relPath;
} else {
urlPath = "/";
String[] arr = url.getPath().split("/");
for (int i = 0; i <= (arr.length - arrRelPath.length); i++) {
String dir = arr[i];
if (dir.length() > 0) {
urlPath += dir + "/";
}
}
// This can be cleaned-up a bit...
if (relPath.substring(0, 1).equals("/")) {
newPath = relPath.substring(1, relPath.length());
} else if (relPath.substring(0, 2).equals("./")) {
newPath = relPath.substring(2, relPath.length());
} else if (relPath.substring(0, 3).equals("../")) {
newPath = relPath.replace("../", "");
} else {
newPath = relPath;
}
}
return urlBase + urlPath + newPath;
} catch (Exception e) {
}
return null;
}
// **************************************************************************
// ** getAbsolutePath
// **************************************************************************
/**
* Returns a fully qualified URL for a given path. See MapPath() method for
* more information.
*
* @deprecated Use MapPath()
*/
@Deprecated
public static String getAbsolutePath(String relPath, String url) {
try {
return MapPath(relPath, new java.net.URL(url));
} catch (Exception e) {
}
return null;
}
} © 2015 - 2025 Weber Informatics LLC | Privacy Policy