https://jsoup.org/: jsoup is a Java library for working with real-world HTML. It provides a very convenient API for extracting and manipulating data, using the best of DOM, CSS, and jquery-like methods. jsoup implements the WHATWG HTML5 specification, and parses HTML to the same DOM as modern browsers do. (Jonathan Hedley)
  • Jonathan Hedley 
package org.jsoup.select;

import org.jsoup.internal.StringUtil;
import org.jsoup.helper.Validate;
import org.jsoup.nodes.Element;
import org.jsoup.nodes.FormElement;
import org.jsoup.nodes.Node;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.List;


A list of Elements, with methods that act on every element in the list. 
 To get an Elements object, use the Element.select(String) method. 


Author:Jonathan Hedley, jonathan@hedley.net
/**
 A list of {@link Element}s, with methods that act on every element in the list.
 <p>
 To get an {@code Elements} object, use the {@link Element#select(String)} method.
 </p>

 @author Jonathan Hedley, jonathan@hedley.net */
public class Elements extends ArrayList<Element> {
    public Elements() {
    }

    public Elements(int initialCapacity) {
        super(initialCapacity);
    }

    public Elements(Collection<Element> elements) {
        super(elements);
    }
    
    public Elements(List<Element> elements) {
        super(elements);
    }
    
    public Elements(Element... elements) {
    	super(Arrays.asList(elements));
    }

    
Creates a deep copy of these elements.

Returns:a deep copy
/**
     * Creates a deep copy of these elements.
     * @return a deep copy
     */
    @Override
	public Elements clone() {
        Elements clone = new Elements(size());

        for(Element e : this)
    		clone.add(e.clone());
    	
    	return clone;
	}

	// attribute methods
    
Get an attribute value from the first matched element that has the attribute.

Params:
  • attributeKey – The attribute key.
See Also:
Returns:The attribute value from the first matched element that has the attribute.. If no elements were matched (isEmpty() == true),
or if the no elements have the attribute, returns empty string.
/**
     Get an attribute value from the first matched element that has the attribute.
     @param attributeKey The attribute key.
     @return The attribute value from the first matched element that has the attribute.. If no elements were matched (isEmpty() == true),
     or if the no elements have the attribute, returns empty string.
     @see #hasAttr(String)
     */
    public String attr(String attributeKey) {
        for (Element element : this) {
            if (element.hasAttr(attributeKey))
                return element.attr(attributeKey);
        }
        return "";
    }

    
Checks if any of the matched elements have this attribute defined.

Params:
  • attributeKey – attribute key
Returns:true if any of the elements have the attribute; false if none do.
/**
     Checks if any of the matched elements have this attribute defined.
     @param attributeKey attribute key
     @return true if any of the elements have the attribute; false if none do.
     */
    public boolean hasAttr(String attributeKey) {
        for (Element element : this) {
            if (element.hasAttr(attributeKey))
                return true;
        }
        return false;
    }

    
Get the attribute value for each of the matched elements. If an element does not have this attribute, no value is
included in the result set for that element.

Params:
  • attributeKey – the attribute name to return values for. You can add the abs: prefix to the key to get absolute URLs from relative URLs, e.g.: doc.select("a").eachAttr("abs:href") .
Returns:a list of each element's attribute value for the attribute
/**
     * Get the attribute value for each of the matched elements. If an element does not have this attribute, no value is
     * included in the result set for that element.
     * @param attributeKey the attribute name to return values for. You can add the {@code abs:} prefix to the key to
     * get absolute URLs from relative URLs, e.g.: {@code doc.select("a").eachAttr("abs:href")} .
     * @return a list of each element's attribute value for the attribute
     */
    public List<String> eachAttr(String attributeKey) {
        List<String> attrs = new ArrayList<>(size());
        for (Element element : this) {
            if (element.hasAttr(attributeKey))
                attrs.add(element.attr(attributeKey));
        }
        return attrs;
    }

    
Set an attribute on all matched elements.

Params:
  • attributeKey – attribute key
  • attributeValue – attribute value
Returns:this
/**
     * Set an attribute on all matched elements.
     * @param attributeKey attribute key
     * @param attributeValue attribute value
     * @return this
     */
    public Elements attr(String attributeKey, String attributeValue) {
        for (Element element : this) {
            element.attr(attributeKey, attributeValue);
        }
        return this;
    }

    
Remove an attribute from every matched element.

Params:
  • attributeKey – The attribute to remove.
Returns:this (for chaining)
/**
     * Remove an attribute from every matched element.
     * @param attributeKey The attribute to remove.
     * @return this (for chaining)
     */
    public Elements removeAttr(String attributeKey) {
        for (Element element : this) {
            element.removeAttr(attributeKey);
        }
        return this;
    }

    
Add the class name to every matched element's class attribute. 
Params:
  • className – class name to add
Returns:this
/**
     Add the class name to every matched element's {@code class} attribute.
     @param className class name to add
     @return this
     */
    public Elements addClass(String className) {
        for (Element element : this) {
            element.addClass(className);
        }
        return this;
    }

    
Remove the class name from every matched element's class attribute, if present. 
Params:
  • className – class name to remove
Returns:this
/**
     Remove the class name from every matched element's {@code class} attribute, if present.
     @param className class name to remove
     @return this
     */
    public Elements removeClass(String className) {
        for (Element element : this) {
            element.removeClass(className);
        }
        return this;
    }

    
Toggle the class name on every matched element's class attribute. 
Params:
  • className – class name to add if missing, or remove if present, from every element.
Returns:this
/**
     Toggle the class name on every matched element's {@code class} attribute.
     @param className class name to add if missing, or remove if present, from every element.
     @return this
     */
    public Elements toggleClass(String className) {
        for (Element element : this) {
            element.toggleClass(className);
        }
        return this;
    }

    
Determine if any of the matched elements have this class name set in their class attribute. 
Params:
  • className – class name to check for
Returns:true if any do, false if none do
/**
     Determine if any of the matched elements have this class name set in their {@code class} attribute.
     @param className class name to check for
     @return true if any do, false if none do
     */
    public boolean hasClass(String className) {
        for (Element element : this) {
            if (element.hasClass(className))
                return true;
        }
        return false;
    }
    
    
Get the form element's value of the first matched element.

See Also:
Returns:The form element's value, or empty if not set.
/**
     * Get the form element's value of the first matched element.
     * @return The form element's value, or empty if not set.
     * @see Element#val()
     */
    public String val() {
        if (size() > 0)
            return first().val();
        else
            return "";
    }
    
    
Set the form element's value in each of the matched elements.

Params:
  • value – The value to set into each matched element
Returns:this (for chaining)
/**
     * Set the form element's value in each of the matched elements.
     * @param value The value to set into each matched element
     * @return this (for chaining)
     */
    public Elements val(String value) {
        for (Element element : this)
            element.val(value);
        return this;
    }
    
    
Get the combined text of all the matched elements.


Note that it is possible to get repeats if the matched elements contain both parent elements and their own
children, as the Element.text() method returns the combined text of a parent and all its children.

See Also:
Returns:string of all text: unescaped and no HTML.
/**
     * Get the combined text of all the matched elements.
     * <p>
     * Note that it is possible to get repeats if the matched elements contain both parent elements and their own
     * children, as the Element.text() method returns the combined text of a parent and all its children.
     * @return string of all text: unescaped and no HTML.
     * @see Element#text()
     * @see #eachText()
     */
    public String text() {
        StringBuilder sb = StringUtil.borrowBuilder();
        for (Element element : this) {
            if (sb.length() != 0)
                sb.append(" ");
            sb.append(element.text());
        }
        return StringUtil.releaseBuilder(sb);
    }

    
Test if any matched Element has any text content, that is not just whitespace.

See Also:
Returns:true if any element has non-blank text content.
/**
     Test if any matched Element has any text content, that is not just whitespace.
     @return true if any element has non-blank text content.
     @see Element#hasText()
     */
    public boolean hasText() {
        for (Element element: this) {
            if (element.hasText())
                return true;
        }
        return false;
    }

    
Get the text content of each of the matched elements. If an element has no text, then it is not included in the
result.

See Also:
Returns:A list of each matched element's text content.
/**
     * Get the text content of each of the matched elements. If an element has no text, then it is not included in the
     * result.
     * @return A list of each matched element's text content.
     * @see Element#text()
     * @see Element#hasText()
     * @see #text()
     */
    public List<String> eachText() {
        ArrayList<String> texts = new ArrayList<>(size());
        for (Element el: this) {
            if (el.hasText())
                texts.add(el.text());
        }
        return texts;
    }
    
    
Get the combined inner HTML of all matched elements.

See Also:
Returns:string of all element's inner HTML.
/**
     * Get the combined inner HTML of all matched elements.
     * @return string of all element's inner HTML.
     * @see #text()
     * @see #outerHtml()
     */
    public String html() {
        StringBuilder sb = StringUtil.borrowBuilder();
        for (Element element : this) {
            if (sb.length() != 0)
                sb.append("\n");
            sb.append(element.html());
        }
        return StringUtil.releaseBuilder(sb);
    }
    
    
Get the combined outer HTML of all matched elements.

See Also:
Returns:string of all element's outer HTML.
/**
     * Get the combined outer HTML of all matched elements.
     * @return string of all element's outer HTML.
     * @see #text()
     * @see #html()
     */
    public String outerHtml() {
        StringBuilder sb = StringUtil.borrowBuilder();
        for (Element element : this) {
            if (sb.length() != 0)
                sb.append("\n");
            sb.append(element.outerHtml());
        }
        return StringUtil.releaseBuilder(sb);
    }

    
Get the combined outer HTML of all matched elements. Alias of outerHtml(). 
See Also:
Returns:string of all element's outer HTML.
/**
     * Get the combined outer HTML of all matched elements. Alias of {@link #outerHtml()}.
     * @return string of all element's outer HTML.
     * @see #text()
     * @see #html()
     */
    @Override
    public String toString() {
        return outerHtml();
    }

    
Update the tag name of each matched element. For example, to change each <i> to a <em>, do doc.select("i").tagName("em"); 
Params:
  • tagName – the new tag name
See Also:
Returns:this, for chaining
/**
     * Update the tag name of each matched element. For example, to change each {@code <i>} to a {@code <em>}, do
     * {@code doc.select("i").tagName("em");}
     * @param tagName the new tag name
     * @return this, for chaining
     * @see Element#tagName(String)
     */
    public Elements tagName(String tagName) {
        for (Element element : this) {
            element.tagName(tagName);
        }
        return this;
    }
    
    
Set the inner HTML of each matched element.

Params:
  • html – HTML to parse and set into each matched element.
See Also:
Returns:this, for chaining
/**
     * Set the inner HTML of each matched element.
     * @param html HTML to parse and set into each matched element.
     * @return this, for chaining
     * @see Element#html(String)
     */
    public Elements html(String html) {
        for (Element element : this) {
            element.html(html);
        }
        return this;
    }
    
    
Add the supplied HTML to the start of each matched element's inner HTML.

Params:
  • html – HTML to add inside each element, before the existing HTML
See Also:
Returns:this, for chaining
/**
     * Add the supplied HTML to the start of each matched element's inner HTML.
     * @param html HTML to add inside each element, before the existing HTML
     * @return this, for chaining
     * @see Element#prepend(String)
     */
    public Elements prepend(String html) {
        for (Element element : this) {
            element.prepend(html);
        }
        return this;
    }
    
    
Add the supplied HTML to the end of each matched element's inner HTML.

Params:
  • html – HTML to add inside each element, after the existing HTML
See Also:
Returns:this, for chaining
/**
     * Add the supplied HTML to the end of each matched element's inner HTML.
     * @param html HTML to add inside each element, after the existing HTML
     * @return this, for chaining
     * @see Element#append(String)
     */
    public Elements append(String html) {
        for (Element element : this) {
            element.append(html);
        }
        return this;
    }
    
    
Insert the supplied HTML before each matched element's outer HTML.

Params:
  • html – HTML to insert before each element
See Also:
Returns:this, for chaining
/**
     * Insert the supplied HTML before each matched element's outer HTML.
     * @param html HTML to insert before each element
     * @return this, for chaining
     * @see Element#before(String)
     */
    public Elements before(String html) {
        for (Element element : this) {
            element.before(html);
        }
        return this;
    }
    
    
Insert the supplied HTML after each matched element's outer HTML.

Params:
  • html – HTML to insert after each element
See Also:
Returns:this, for chaining
/**
     * Insert the supplied HTML after each matched element's outer HTML.
     * @param html HTML to insert after each element
     * @return this, for chaining
     * @see Element#after(String)
     */
    public Elements after(String html) {
        for (Element element : this) {
            element.after(html);
        }
        return this;
    }

    
Wrap the supplied HTML around each matched elements. For example, with HTML <p><b>This</b> is <b>Jsoup</b></p>, doc.select("b").wrap("<i></i>"); becomes <p><i><b>This</b></i> is <i><b>jsoup</b></i></p> 
Params:
  • html – HTML to wrap around each element, e.g. <div class="head"></div>. Can be arbitrarily deep.
See Also:
Returns:this (for chaining)
/**
     Wrap the supplied HTML around each matched elements. For example, with HTML
     {@code <p><b>This</b> is <b>Jsoup</b></p>},
     <code>doc.select("b").wrap("&lt;i&gt;&lt;/i&gt;");</code>
     becomes {@code <p><i><b>This</b></i> is <i><b>jsoup</b></i></p>}
     @param html HTML to wrap around each element, e.g. {@code <div class="head"></div>}. Can be arbitrarily deep.
     @return this (for chaining)
     @see Element#wrap
     */
    public Elements wrap(String html) {
        Validate.notEmpty(html);
        for (Element element : this) {
            element.wrap(html);
        }
        return this;
    }

    
Removes the matched elements from the DOM, and moves their children up into their parents. This has the effect of
dropping the elements but keeping their children.


This is useful for e.g removing unwanted formatting elements but keeping their contents.


E.g. with HTML: 
<div><font>One</font> <font><a href="/">Two</a></font></div>


doc.select("font").unwrap();


HTML = <div>One <a href="/">Two</a></div>


See Also:
Returns:this (for chaining)
/**
     * Removes the matched elements from the DOM, and moves their children up into their parents. This has the effect of
     * dropping the elements but keeping their children.
     * <p>
     * This is useful for e.g removing unwanted formatting elements but keeping their contents.
     * </p>
     * 
     * E.g. with HTML: <p>{@code <div><font>One</font> <font><a href="/">Two</a></font></div>}</p>
     * <p>{@code doc.select("font").unwrap();}</p>
     * <p>HTML = {@code <div>One <a href="/">Two</a></div>}</p>
     *
     * @return this (for chaining)
     * @see Node#unwrap
     */
    public Elements unwrap() {
        for (Element element : this) {
            element.unwrap();
        }
        return this;
    }

    
Empty (remove all child nodes from) each matched element. This is similar to setting the inner HTML of each
element to nothing.

 E.g. HTML: <div><p>Hello <b>there</b></p> <p>now</p></div>

doc.select("p").empty();
 HTML = <div><p></p> <p></p></div> 
See Also:
Returns:this, for chaining
/**
     * Empty (remove all child nodes from) each matched element. This is similar to setting the inner HTML of each
     * element to nothing.
     * <p>
     * E.g. HTML: {@code <div><p>Hello <b>there</b></p> <p>now</p></div>}<br>
     * <code>doc.select("p").empty();</code><br>
     * HTML = {@code <div><p></p> <p></p></div>}
     * @return this, for chaining
     * @see Element#empty()
     * @see #remove()
     */
    public Elements empty() {
        for (Element element : this) {
            element.empty();
        }
        return this;
    }

    
Remove each matched element from the DOM. This is similar to setting the outer HTML of each element to nothing.

 E.g. HTML: <div><p>Hello</p> <p>there</p> <img /></div>

doc.select("p").remove();
 HTML = <div> <img /></div> 
 Note that this method should not be used to clean user-submitted HTML; rather, use Cleaner to clean HTML. 
See Also:
Returns:this, for chaining
/**
     * Remove each matched element from the DOM. This is similar to setting the outer HTML of each element to nothing.
     * <p>
     * E.g. HTML: {@code <div><p>Hello</p> <p>there</p> <img /></div>}<br>
     * <code>doc.select("p").remove();</code><br>
     * HTML = {@code <div> <img /></div>}
     * <p>
     * Note that this method should not be used to clean user-submitted HTML; rather, use {@link org.jsoup.safety.Cleaner} to clean HTML.
     * @return this, for chaining
     * @see Element#empty()
     * @see #empty()
     */
    public Elements remove() {
        for (Element element : this) {
            element.remove();
        }
        return this;
    }
    
    // filters
    
    
Find matching elements within this element list.

Params:
Returns:the filtered list of elements, or an empty list if none match.
/**
     * Find matching elements within this element list.
     * @param query A {@link Selector} query
     * @return the filtered list of elements, or an empty list if none match.
     */
    public Elements select(String query) {
        return Selector.select(query, this);
    }

    
Remove elements from this list that match the Selector query. 
 E.g. HTML: <div class=logo>One</div> <div>Two</div>

Elements divs = doc.select("div").not(".logo");
 Result: divs: [<div>Two</div>] 


Params:
  • query – the selector query whose results should be removed from these elements
Returns:a new elements list that contains only the filtered results
/**
     * Remove elements from this list that match the {@link Selector} query.
     * <p>
     * E.g. HTML: {@code <div class=logo>One</div> <div>Two</div>}<br>
     * <code>Elements divs = doc.select("div").not(".logo");</code><br>
     * Result: {@code divs: [<div>Two</div>]}
     * <p>
     * @param query the selector query whose results should be removed from these elements
     * @return a new elements list that contains only the filtered results
     */
    public Elements not(String query) {
        Elements out = Selector.select(query, this);
        return Selector.filterOut(this, out);
    }
    
    
Get the nth matched element as an Elements object.

 See also ArrayList<Element>.get(int) to retrieve an Element. 
Params:
  • index – the (zero-based) index of the element in the list to retain
Returns:Elements containing only the specified element, or, if that element did not exist, an empty list.
/**
     * Get the <i>nth</i> matched element as an Elements object.
     * <p>
     * See also {@link #get(int)} to retrieve an Element.
     * @param index the (zero-based) index of the element in the list to retain
     * @return Elements containing only the specified element, or, if that element did not exist, an empty list.
     */
    public Elements eq(int index) {
        return size() > index ? new Elements(get(index)) : new Elements();
    }
    
    
Test if any of the matched elements match the supplied query.

Params:
  • query – A selector
Returns:true if at least one element in the list matches the query.
/**
     * Test if any of the matched elements match the supplied query.
     * @param query A selector
     * @return true if at least one element in the list matches the query.
     */
    public boolean is(String query) {
        Evaluator eval = QueryParser.parse(query);
        for (Element e : this) {
            if (e.is(eval))
                return true;
        }
        return false;
    }

    
Get the immediate next element sibling of each element in this list.

Returns:next element siblings.
/**
     * Get the immediate next element sibling of each element in this list.
     * @return next element siblings.
     */
    public Elements next() {
        return siblings(null, true, false);
    }

    
Get the immediate next element sibling of each element in this list, filtered by the query.

Params:
  • query – CSS query to match siblings against
Returns:next element siblings.
/**
     * Get the immediate next element sibling of each element in this list, filtered by the query.
     * @param query CSS query to match siblings against
     * @return next element siblings.
     */
    public Elements next(String query) {
        return siblings(query, true, false);
    }

    
Get each of the following element siblings of each element in this list.

Returns:all following element siblings.
/**
     * Get each of the following element siblings of each element in this list.
     * @return all following element siblings.
     */
    public Elements nextAll() {
        return siblings(null, true, true);
    }

    
Get each of the following element siblings of each element in this list, that match the query.

Params:
  • query – CSS query to match siblings against
Returns:all following element siblings.
/**
     * Get each of the following element siblings of each element in this list, that match the query.
     * @param query CSS query to match siblings against
     * @return all following element siblings.
     */
    public Elements nextAll(String query) {
        return siblings(query, true, true);
    }

    
Get the immediate previous element sibling of each element in this list.

Returns:previous element siblings.
/**
     * Get the immediate previous element sibling of each element in this list.
     * @return previous element siblings.
     */
    public Elements prev() {
        return siblings(null, false, false);
    }

    
Get the immediate previous element sibling of each element in this list, filtered by the query.

Params:
  • query – CSS query to match siblings against
Returns:previous element siblings.
/**
     * Get the immediate previous element sibling of each element in this list, filtered by the query.
     * @param query CSS query to match siblings against
     * @return previous element siblings.
     */
    public Elements prev(String query) {
        return siblings(query, false, false);
    }

    
Get each of the previous element siblings of each element in this list.

Returns:all previous element siblings.
/**
     * Get each of the previous element siblings of each element in this list.
     * @return all previous element siblings.
     */
    public Elements prevAll() {
        return siblings(null, false, true);
    }

    
Get each of the previous element siblings of each element in this list, that match the query.

Params:
  • query – CSS query to match siblings against
Returns:all previous element siblings.
/**
     * Get each of the previous element siblings of each element in this list, that match the query.
     * @param query CSS query to match siblings against
     * @return all previous element siblings.
     */
    public Elements prevAll(String query) {
        return siblings(query, false, true);
    }

    private Elements siblings(String query, boolean next, boolean all) {
        Elements els = new Elements();
        Evaluator eval = query != null? QueryParser.parse(query) : null;
        for (Element e : this) {
            do {
                Element sib = next ? e.nextElementSibling() : e.previousElementSibling();
                if (sib == null) break;
                if (eval == null)
                    els.add(sib);
                else if (sib.is(eval))
                    els.add(sib);
                e = sib;
            } while (all);
        }
        return els;
    }

    
Get all of the parents and ancestor elements of the matched elements.

Returns:all of the parents and ancestor elements of the matched elements
/**
     * Get all of the parents and ancestor elements of the matched elements.
     * @return all of the parents and ancestor elements of the matched elements
     */
    public Elements parents() {
        HashSet<Element> combo = new LinkedHashSet<>();
        for (Element e: this) {
            combo.addAll(e.parents());
        }
        return new Elements(combo);
    }

    // list-like methods
    
Get the first matched element.

Returns:The first matched element, or null if contents is empty.
/**
     Get the first matched element.
     @return The first matched element, or <code>null</code> if contents is empty.
     */
    public Element first() {
        return isEmpty() ? null : get(0);
    }

    
Get the last matched element.

Returns:The last matched element, or null if contents is empty.
/**
     Get the last matched element.
     @return The last matched element, or <code>null</code> if contents is empty.
     */
    public Element last() {
        return isEmpty() ? null : get(size() - 1);
    }

    
Perform a depth-first traversal on each of the selected elements.

Params:
  • nodeVisitor – the visitor callbacks to perform on each node
Returns:this, for chaining
/**
     * Perform a depth-first traversal on each of the selected elements.
     * @param nodeVisitor the visitor callbacks to perform on each node
     * @return this, for chaining
     */
    public Elements traverse(NodeVisitor nodeVisitor) {
        NodeTraversor.traverse(nodeVisitor, this);
        return this;
    }

    
Perform a depth-first filtering on each of the selected elements.

Params:
  • nodeFilter – the filter callbacks to perform on each node
Returns:this, for chaining
/**
     * Perform a depth-first filtering on each of the selected elements.
     * @param nodeFilter the filter callbacks to perform on each node
     * @return this, for chaining
     */
    public Elements filter(NodeFilter nodeFilter) {
        NodeTraversor.filter(nodeFilter, this);
        return this;
    }

    
Get the FormElement forms from the selected elements, if any. 
Returns:a list of FormElements pulled from the matched elements. The list will be empty if the elements contain no forms.
/**
     * Get the {@link FormElement} forms from the selected elements, if any.
     * @return a list of {@link FormElement}s pulled from the matched elements. The list will be empty if the elements contain
     * no forms.
     */
    public List<FormElement> forms() {
        ArrayList<FormElement> forms = new ArrayList<>();
        for (Element el: this)
            if (el instanceof FormElement)
                forms.add((FormElement) el);
        return forms;
    }

}