Java XML Child Element Text getChildElementValueByTagName(Element ele, String childEleName)

Description

Utility method that returns the first child element value identified by its name.

License

Apache License

Parameter

Parameter	Description
ele	the DOM element to analyze
childEleName	the child element name to look for

Return

the extracted text value, or null if no child element found

Declaration

public static String getChildElementValueByTagName(Element ele, String childEleName) 

Method Source Code

//package com.java2s;
/*//from  w  w  w  .j a va  2  s.c  o m
 * Copyright 2002-2008 the original author or authors.
 *
 * Licensed 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
 *
 *      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 java.util.Collection;

import org.springframework.util.Assert;
import org.w3c.dom.CharacterData;
import org.w3c.dom.Comment;
import org.w3c.dom.Element;
import org.w3c.dom.EntityReference;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;

public class Main {
    /**
     * Utility method that returns the first child element value identified by its name.
     *
     * @param ele        the DOM element to analyze
     * @param childEleName the child element name to look for
     * @return the extracted text value, or <code>null</code> if no child element found
     */
    public static String getChildElementValueByTagName(Element ele, String childEleName) {
        Element child = getChildElementByTagName(ele, childEleName);
        return (child != null ? getTextValue(child) : null);
    }

    /**
     * Utility method that returns the first child element identified by its name.
     *
     * @param ele        the DOM element to analyze
     * @param childEleName the child element name to look for
     * @return the <code>org.w3c.dom.Element</code> instance, or <code>null</code> if none found
     */
    public static Element getChildElementByTagName(Element ele, String childEleName) {
        Assert.notNull(ele, "Element must not be null");
        Assert.notNull(childEleName, "Element name must not be null");
        NodeList nl = ele.getChildNodes();
        for (int i = 0; i < nl.getLength(); i++) {
            Node node = nl.item(i);
            if (node instanceof Element && nodeNameMatch(node, childEleName)) {
                return (Element) node;
            }
        }
        return null;
    }

    /**
     * Extract the text value from the given DOM element, ignoring XML comments. <p>Appends all CharacterData nodes and
     * EntityReference nodes into a single String value, excluding Comment nodes.
     *
     * @see CharacterData
     * @see EntityReference
     * @see Comment
     */
    public static String getTextValue(Element valueEle) {
        Assert.notNull(valueEle, "Element must not be null");
        StringBuilder sb = new StringBuilder();
        NodeList nl = valueEle.getChildNodes();
        for (int i = 0; i < nl.getLength(); i++) {
            Node item = nl.item(i);
            if ((item instanceof CharacterData && !(item instanceof Comment)) || item instanceof EntityReference) {
                sb.append(item.getNodeValue());
            }
        }
        return sb.toString();
    }

    /** Matches the given node's name and local name against the given desired name. */
    private static boolean nodeNameMatch(Node node, String desiredName) {
        return (desiredName.equals(node.getNodeName()) || desiredName.equals(node.getLocalName()));
    }

    /** Matches the given node's name and local name against the given desired names. */
    private static boolean nodeNameMatch(Node node, Collection desiredNames) {
        return (desiredNames.contains(node.getNodeName()) || desiredNames.contains(node.getLocalName()));
    }
}

Related

1. getChildElementTextValue(Node parent, String name)
2. getChildElementValue(Element p_rootElement, String p_elementName)
3. getChildElementValue(Element parent, String name)
4. getChildElementValue(Element parentElm, String elementName, String defaultValue)
5. getChildElementValueByTagName(Element ele, String childEleName)
6. getChildElementValueByTagName(Element parentElement, String childTag)
7. getChildText(Element elem, String childTagName)
8. getChildText(Element element, String defaultValue)
9. getChildText(Element element, String nodeName)