Android XML Node Search getOptionalXmlString(Node node, String xmlLocalName)

Description

Retrieves the value of that XML element as a string.

License

Apache License

Parameter

Parameter	Description
node	The XML <em>parent</em> node to parse.
xmlLocalName	The XML local name to find in the parent node.

Return

The text content of the element. Returns null when the element is missing. Returns an empty string whether the element is present but empty.

Declaration

public static String getOptionalXmlString(Node node, String xmlLocalName)

Method Source Code

//package com.java2s;
/*// w  w  w  . java 2s  .  c  o m
 * Copyright (C) 2009 The Android Open Source Project
 *
 * 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 org.w3c.dom.Node;

public class Main {
    /**
     * Retrieves the value of that XML element as a string.
     * Returns null when the element is missing, so you can tell between a missing element
     * and an empty one.
     * <p/>
     * Note: use {@link #getXmlString(Node, String)} if you don't need to know when the
     * element is missing versus empty.
     *
     * @param node The XML <em>parent</em> node to parse.
     * @param xmlLocalName The XML local name to find in the parent node.
     * @return The text content of the element. Returns null when the element is missing.
     *         Returns an empty string whether the element is present but empty.
     */
    public static String getOptionalXmlString(Node node, String xmlLocalName) {
        Node child = getFirstChild(node, xmlLocalName);

        return child == null ? null : child.getTextContent(); //$NON-NLS-1$
    }

    /**
     * Returns the first child element with the given XML local name.
     * If xmlLocalName is null, returns the very first child element.
     */
    public static Node getFirstChild(Node node, String xmlLocalName) {

        String nsUri = node.getNamespaceURI();
        for (Node child = node.getFirstChild(); child != null; child = child
                .getNextSibling()) {
            if (child.getNodeType() == Node.ELEMENT_NODE
                    && nsUri.equals(child.getNamespaceURI())) {
                if (xmlLocalName == null
                        || xmlLocalName.equals(child.getLocalName())) {
                    return child;
                }
            }
        }

        return null;
    }
}