code: /**
   * This file is part of Eclipse Steady.
   *
   * 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.
   *
   * SPDX-License-Identifier: Apache-2.0
   * SPDX-FileCopyrightText: Copyright (c) 2018-2020 SAP SE or an SAP affiliate company and Eclipse Steady contributors
   */
  package org.eclipse.steady.java;
  
  import java.util.Arrays;
  import java.util.Stack;
  
  import org.apache.logging.log4j.Logger;
  import org.eclipse.steady.shared.json.model.LibraryId;
  import org.xml.sax.Attributes;
  import org.xml.sax.SAXException;
  import org.xml.sax.helpers.DefaultHandler;
  
  /**
   * Creates a {@link LibraryId} for a given pom.xml.
   */
  public class PomParser extends DefaultHandler {
  
    private static final Logger log = org.apache.logging.log4j.LogManager.getLogger(PomParser.class);
  
    private static final String[] pg = new String[] {"project", "parent", "groupId"};
    private static final String[] pa = new String[] {"project", "parent", "artifactId"};
    private static final String[] pv = new String[] {"project", "parent", "version"};
  
    private static final String[] g = new String[] {"project", "groupId"};
    private static final String[] a = new String[] {"project", "artifactId"};
    private static final String[] v = new String[] {"project", "version"};
  
    private Stack<String> stack = new Stack<String>();
  
    private LibraryId libid = new LibraryId();
  
    /** {@inheritDoc} */
    public void startElement(String namespaceURI, String localName, String qName, Attributes atts)
        throws SAXException {
      this.stack.push(localName);
    }
  
    /** {@inheritDoc} */
    public void characters(char ch[], int start, int length) throws SAXException {
      // log.info(stack.toString());
      if (Arrays.equals(stack.toArray(), pg) || Arrays.equals(stack.toArray(), g)) {
        if (libid.getMvnGroup() == null || Arrays.equals(stack.toArray(), g))
          libid.setMvnGroup(new String(Arrays.copyOfRange(ch, start, start + length)));
      } else if (Arrays.equals(stack.toArray(), pa) || Arrays.equals(stack.toArray(), a)) {
        if (libid.getArtifact() == null || Arrays.equals(stack.toArray(), a))
          libid.setArtifact(new String(Arrays.copyOfRange(ch, start, start + length)));
      } else if (Arrays.equals(stack.toArray(), pv) || Arrays.equals(stack.toArray(), v)) {
        if (libid.getVersion() == null || Arrays.equals(stack.toArray(), v))
          libid.setVersion(new String(Arrays.copyOfRange(ch, start, start + length)));
      }
    }
  
    /** {@inheritDoc} */
    public void endElement(String namespaceURI, String localName, String qName) throws SAXException {
      this.stack.pop();
    }
  
    /**
     * <p>getLibraryId.</p>
     *
     * @return a {@link org.eclipse.steady.shared.json.model.LibraryId} object.
     */
    public LibraryId getLibraryId() {
      return this.libid;
    }
  }
  