Java XML Element Check isEmpty(final Element el)

Description

See if this node is empty

License

Apache License

Parameter

Parameter	Description
el	a parameter

Exception

Parameter	Description
SAXException	an exception

Return

boolean true for empty

Declaration

public static boolean isEmpty(final Element el) throws SAXException 

Method Source Code

//package com.java2s;
/* ********************************************************************
Licensed to Jasig under one or more contributor license
agreements. See the NOTICE file distributed with this work
for additional information regarding copyright ownership.
Jasig licenses this file to you under the Apache License,
Version 2.0 (the "License"); you may not use this file
except in compliance with the License. You may obtain a
copy of the License at://from w w w. j a  v a2  s.c  om
    
http://www.apache.org/licenses/LICENSE-2.0
    
Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on
an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied. See the License for the
specific language governing permissions and limitations
under the License.
*/

import org.w3c.dom.Element;

import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

public class Main {
    /** See if this node is empty
     *
     * @param el
     * @return boolean   true for empty
     * @throws SAXException
     */
    public static boolean isEmpty(final Element el) throws SAXException {
        return !hasChildren(el) && !hasContent(el);
    }

    /** See if this node has any children
     *
     * @param el
     * @return boolean   true for any child elements
     * @throws SAXException
     */
    public static boolean hasChildren(final Element el) throws SAXException {
        NodeList children = el.getChildNodes();

        for (int i = 0; i < children.getLength(); i++) {
            Node curnode = children.item(i);

            short ntype = curnode.getNodeType();
            if ((ntype != Node.TEXT_NODE) && (ntype != Node.CDATA_SECTION_NODE) && (ntype != Node.COMMENT_NODE)) {
                return true;
            }
        }

        return false;
    }

    /** Return true if the current element has non zero length content.
     *
     * @param el
     * @return boolean
     * @throws SAXException
     */
    public static boolean hasContent(final Element el) throws SAXException {
        String s = getElementContent(el);

        return (s != null) && (s.length() > 0);
    }

    /** Return the content for the current element. All leading and trailing
     * whitespace and embedded comments will be removed.
     *
     * <p>This is only intended for an element with no child elements.
     *
     * @param el
     * @param trim true to trim surrounding white-space
     * @return element content
     * @throws SAXException
     */
    public static String getElementContent(final Element el, final boolean trim) throws SAXException {
        StringBuilder sb = new StringBuilder();

        NodeList children = el.getChildNodes();

        for (int i = 0; i < children.getLength(); i++) {
            Node curnode = children.item(i);

            if (curnode.getNodeType() == Node.TEXT_NODE) {
                sb.append(curnode.getNodeValue());
            } else if (curnode.getNodeType() == Node.CDATA_SECTION_NODE) {
                sb.append(curnode.getNodeValue());
            } else if (curnode.getNodeType() == Node.COMMENT_NODE) {
                // Ignore
            } else {
                throw new SAXException(
                        "Unexpected child node " + curnode.getLocalName() + " for " + el.getLocalName());
            }
        }

        if (!trim) {
            return sb.toString();
        }

        return sb.toString().trim();
    }

    /** Return the content for the current element. All leading and trailing
     * whitespace and embedded comments will be removed.
     *
     * <p>This is only intended for an element with no child elements.
     *
     * @param el
     * @return element content
     * @throws SAXException
     */
    public static String getElementContent(final Element el) throws SAXException {
        return getElementContent(el, true);
    }
}

Related

1. isAsyncEventQueue(Element element)
2. isComputedGoal(final Element element)
3. isElement(XMLStreamReader xmlRdr, int eventType, String tagName)
4. isElementExistsByTagName(final Element element, final String tagName)
5. isElementNamed(Element e, String ns, String localName)
6. isEmptyElement(Element el)
7. isExtension(Element element)
8. isGateway(Element element)
9. isHTMLElement(Element elem)