com.collabnet.ccf.core.utils.XPathUtils.java Source code

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Here is the source code for com.collabnet.ccf.core.utils.XPathUtils.java

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/*
 * Copyright 2009 CollabNet, Inc. ("CollabNet") 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.
 */

package com.collabnet.ccf.core.utils;

import java.util.Collections;
import java.util.Map;

import org.dom4j.Document;
import org.dom4j.Element;
import org.dom4j.Node;
import org.dom4j.XPath;
import org.dom4j.xpath.DefaultXPath;

import com.collabnet.ccf.core.ga.GenericArtifactParsingException;

public class XPathUtils {

    private static final String ARTIFACT_ROOT_ELEMENT_NAME = "artifact";
    private static final String CCF_ARTIFACT_NAMESPACE = "http://ccf.open.collab.net/GenericArtifactV1.0";
    private static final String CCF_NAMESPACE_PREFIX = "ccf";
    private static Map<String, String> ccfNamespaceMap = Collections.singletonMap(CCF_NAMESPACE_PREFIX,
            CCF_ARTIFACT_NAMESPACE);

    /**
     * Adds an attribute with the supplied value to the supplied element
     * 
     * @param element
     *            element in question
     * @param attributeName
     *            attribute name in question
     * @param value
     *            value of the attribute
     */
    public static void addAttribute(Element element, String attributeName, String value) {
        element.addAttribute(attributeName, value);
        // element.remove();
    }

    /**
     * Extracts the value of the supplied attribute
     * 
     * @param element
     *            element with attribute in question
     * @param attributeName
     *            name of the attribute in question
     * @return value of the attribute in question
     * @throws GenericArtifactParsingException
     *             exception s thrown is attribute is missing
     */
    public static String getAttributeValue(Element element, String attributeName)
            throws GenericArtifactParsingException {
        return getAttributeValue(element, attributeName, true);
    }

    /**
     * Extracts the value of the supplied attribute
     * 
     * @param element
     *            element with attribute in question
     * @param attributeName
     *            name of the attribute in question
     * @param failIfNotFound
     *            determines if exception should be thrown if attribute is not
     *            found
     * @return value of the attribute in question, null if not found and
     *         failIfNotFound is set to false
     * @throws GenericArtifactParsingException
     *             exception thrown is attribute is missing and failIfNotFound
     *             is set to true
     */
    public static String getAttributeValue(Element element, String attributeName, boolean failIfNotFound)
            throws GenericArtifactParsingException {
        XPath xpath = new DefaultXPath("@" + attributeName);
        xpath.setNamespaceURIs(ccfNamespaceMap);
        Node attributeNode = xpath.selectSingleNode(element);
        if (attributeNode == null) {
            if (failIfNotFound) {
                throw new GenericArtifactParsingException(
                        "Missing attribute: " + attributeName + " in element " + element.getName());
            } else {
                return null;
            }
        } else {
            return attributeNode.getText();
        }
    }

    /**
     * Extracts the artifact-root-element out of a Dom4J XML document
     * 
     * @param document
     *            XML document in question
     * @return generic artifact root-element
     * @throws GenericArtifactParsingException
     *             thrown if document is not compliant to the generic artifact
     *             schema
     */
    public static Element getRootElement(Document document) throws GenericArtifactParsingException {
        Element rootElement = document.getRootElement();
        if (rootElement == null) {
            throw new GenericArtifactParsingException(
                    "Received empty XML document. The reason might be an invalid data mapping.");
        }
        if (!ARTIFACT_ROOT_ELEMENT_NAME.equals(rootElement.getName()))
            throw new GenericArtifactParsingException("Root-element of XML document is not named "
                    + ARTIFACT_ROOT_ELEMENT_NAME + "but " + rootElement.getName());
        if (!CCF_ARTIFACT_NAMESPACE.equals(rootElement.getNamespaceURI()))
            throw new GenericArtifactParsingException("Namespace-URI of root-element of XML document is not named "
                    + CCF_ARTIFACT_NAMESPACE + "but " + rootElement.getNamespaceURI());
        return rootElement;
    }

}