Java XML Element Get getElements(Element root)

Description

Get all child elements of the specified (root) element.

License

Open Source License

Parameter

Parameter	Description
root	The element to search.

Return

An array of all child elements of the root.

Declaration

public static ArrayList<Element> getElements(Element root) 

Method Source Code

//package com.java2s;
/*******************************************************************************
 * Copyright (c) 2012 Firestar Software, Inc.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:/* w  w w  . ja v a 2 s.c  o m*/
 *     Firestar Software, Inc. - initial API and implementation
 *
 * Author:
 *     Gabriel Oancea
 *
 *******************************************************************************/

import java.util.*;

import org.w3c.dom.*;

public class Main {
    /**
     * Get all child elements of the specified (root) element. If the root is null, an illegal argument exception is
     * thrown. If the root has no children, an empty array is returned.
     * 
     * @param root The element to search.
     * @return An array of all child elements of the root.
     */
    public static ArrayList<Element> getElements(Element root) {
        if (root == null)
            throw new IllegalArgumentException(
                    "Null or invalid root element!");
        NodeList lst = root.getChildNodes();
        final int n = lst.getLength();
        ArrayList<Element> a = new ArrayList<Element>(n);
        for (int i = 0; i < n; i++) {
            Node node = lst.item(i);
            if (node.getNodeType() == Node.ELEMENT_NODE)
                a.add((Element) node);
        }
        return a;
    }

    /**
     * Get all child elements of the specified (root) element, that are named by the specified name. If the root is null,
     * an illegal argument exception is thrown. If the root has no children by the specified name, an empty array is
     * returned.
     * 
     * @param root The element to search.
     * @param name The name of the child elements to look for.
     * @return An array of the child elements named by the specified name, of the root.
     */
    public static ArrayList<Element> getElements(Element root, String name) {
        if (root == null || name == null || name.length() <= 0)
            throw new IllegalArgumentException(
                    "Null or invalid root element or name!");
        NodeList lst = root.getChildNodes();
        int size = lst.getLength();
        ArrayList<Element> a = new ArrayList<Element>(size / 2);
        name = localName(name);
        for (int i = 0; i < size; i++) {
            Node node = lst.item(i);
            if (node.getNodeType() == Node.ELEMENT_NODE) {
                String nodeName = localName(node);
                if (name.equals(nodeName))
                    a.add((Element) node);
            }
        }
        return a;
    }

    /**
     * Get the local name of a node (that may have a prefix). For example <code>localName( "xsd:string" )</code> will
     * return <code>"string"</code>
     * 
     * @param name A node name (normally a DOM Element).
     * @return The local part of the name.
     */
    public static String localName(String name) {
        if (name == null || name.length() <= 0)
            return name;
        int p = name.indexOf(':');
        if (p < 0 || p + 1 >= name.length())
            return name;
        return name.substring(p + 1);
    }

    /**
     * Get the local name of a node (that may have a prefix).
     * 
     * @param name The node (normally a DOM Element).
     * @return The local part of the name.
     */
    public static String localName(Node node) {
        if (node == null)
            return null;
        String name = node.getLocalName();
        if (name == null || name.length() <= 0)
            return localName(node.getNodeName());
        return name;
    }
}

Related

1. getElements(Element document, String elementName, String attrName, String attrValue)
2. getElements(Element elem, String path)
3. getElements(Element element)
4. getElements(Element element, String tagName)
5. getElements(Element node)
6. getElements(Element root, String element)
7. getElements(Element root, String tagName)
8. getElements(Element topElm)
9. getElements(final String elementName, final InputStream is, final boolean onlyValues)