org.eclipse.skalli.maven/src/main/java/org/eclipse/skalli/model/ext/maven/internal/MavenPomParserImpl.java

/*******************************************************************************
 * Copyright (c) 2010-2014 SAP AG and others.
 * 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:
 *     SAP AG - initial API and implementation
 *******************************************************************************/
package org.eclipse.skalli.model.ext.maven.internal;

import java.io.IOException;
import java.io.InputStream;

import javax.xml.parsers.ParserConfigurationException;

import org.apache.commons.lang.StringUtils;
import org.eclipse.skalli.commons.XMLUtils;
import org.eclipse.skalli.model.ValidationException;
import org.eclipse.skalli.model.ext.maven.MavenModule;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.NodeList;
import org.xml.sax.SAXException;

public class MavenPomParserImpl implements MavenPomParser {

    private static final String MODULE = "module"; //$NON-NLS-1$
    private static final String RELATIVE_PATH = "relativePath"; //$NON-NLS-1$
    private static final String PARENT = "parent"; //$NON-NLS-1$
    private static final String PROJECT = "project"; //$NON-NLS-1$
    private static final String PACKAGING = "packaging"; //$NON-NLS-1$
    private static final String ARTIFACT_ID = "artifactId"; //$NON-NLS-1$
    private static final String GROUP_ID = "groupId"; //$NON-NLS-1$
    private static final String NAME = "name"; //$NON-NLS-1$
    private static final String DESCRIPTION = "description"; //$NON-NLS-1$
    private static final String CLASSIFIER = "classifier"; //$NON-NLS-1$

    @Override
    public MavenPom parse(InputStream in) throws IOException, ValidationException {
        Document document;
        try {
            document = XMLUtils.documentFromStream(in);
        } catch (ParserConfigurationException e) {
            throw new RuntimeException(e);
        } catch (SAXException e) {
            throw new ValidationException(e);
        }
        return parse(document);
    }

    private MavenPom parse(Document document) {
        MavenPom result = new MavenPom();

        MavenModule self = parseMavenCoordinate(document, PROJECT);
        result.setSelf(self);

        if (elementExists(document, PARENT)) {
            MavenModule parent = parseMavenCoordinate(document, PARENT);
            result.setParent(parent);

            String relativePath = extractTextContent(document, PARENT, RELATIVE_PATH);
            result.setParentRelativePath(relativePath);
        }

        NodeList modules = document.getElementsByTagName(MODULE);
        for (int i = 0; i < modules.getLength(); ++i) {
            String text = StringUtils.strip(modules.item(i).getTextContent());
            if (StringUtils.isNotBlank(text)) {
                result.getModuleTags().add(text);
            }
        }

        return result;
    }

    private MavenModule parseMavenCoordinate(Document document, String parentTagName) {
        MavenModule coordinate = new MavenModule();

        coordinate.setGroupId(extractTextContent(document, parentTagName, GROUP_ID));
        coordinate.setArtefactId(extractTextContent(document, parentTagName, ARTIFACT_ID));
        coordinate.setPackaging(extractTextContent(document, parentTagName, PACKAGING));
        coordinate.setName(extractTextContent(document, parentTagName, NAME));
        coordinate.setDescription(extractTextContent(document, parentTagName, DESCRIPTION));
        coordinate.setClassifier(extractTextContent(document, parentTagName, CLASSIFIER));

        return coordinate;
    }

    private boolean elementExists(Document document, String tagName) {
        return document.getElementsByTagName(tagName).getLength() > 0;
    }

    private String extractTextContent(Document document, String parentTagName, String tagName) {
        String textContent = null;
        NodeList parentNodes = document.getElementsByTagName(parentTagName);
        if (parentNodes.getLength() > 0) {
            Node parent = parentNodes.item(0);
            NodeList children = parent.getChildNodes();
            for (int i = 0; i < children.getLength(); i++) {
                Node node = children.item(i);
                if (tagName.equals(node.getNodeName())) {
                    textContent =  StringUtils.strip(node.getTextContent());
                    break;
                }
            }
        }
        return textContent;
    }
}