content: /*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you 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 org.apache.ambari.server.view;
  
  import java.io.File;
  import java.io.FileInputStream;
  import java.io.FileNotFoundException;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.io.InputStream;
  import java.net.URL;
  import java.net.URLClassLoader;
  import java.util.jar.JarInputStream;
  
  import javax.xml.XMLConstants;
  import javax.xml.bind.JAXBContext;
  import javax.xml.bind.JAXBException;
  import javax.xml.bind.Unmarshaller;
  import javax.xml.transform.stream.StreamSource;
  import javax.xml.validation.Schema;
  import javax.xml.validation.SchemaFactory;
  
  import org.apache.ambari.server.view.configuration.ViewConfig;
  import org.xml.sax.SAXException;
  
  /**
   * Helper class for basic view archive utility.
   */
  public class ViewArchiveUtility {
  
    /**
     * Constants
     */
    private static final String VIEW_XML = "view.xml";
    private static final String WEB_INF_VIEW_XML = "WEB-INF/classes/" + VIEW_XML;
    private static final String VIEW_XSD = "view.xsd";
  
  
    // ----- ViewArchiveUtility ------------------------------------------------
  
    /**
     * Get the view configuration from the given archive file.
     *
     * @param archiveFile  the archive file
     *
     * @return the associated view configuration
     *
     * @throws JAXBException if xml is malformed
     */
    public ViewConfig getViewConfigFromArchive(File archiveFile)
        throws JAXBException, IOException {
      ClassLoader cl = URLClassLoader.newInstance(new URL[]{archiveFile.toURI().toURL()}, null);
  
      InputStream configStream = cl.getResourceAsStream(VIEW_XML);
      if (configStream == null) {
        configStream = cl.getResourceAsStream(WEB_INF_VIEW_XML);
        if (configStream == null) {
          throw new IllegalStateException(
              String.format("Archive %s doesn't contain a view descriptor.", archiveFile.getAbsolutePath()));
        }
      }
  
      try {
  
        JAXBContext jaxbContext       = JAXBContext.newInstance(ViewConfig.class);
        Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
  
        return (ViewConfig) jaxbUnmarshaller.unmarshal(configStream);
      } finally {
        configStream.close();
      }
    }
  
    /**
     * Get the view configuration from the extracted archive file.
     *
     * @param archivePath  path to extracted archive
     * @param validate     indicates whether or not the view configuration should be validated
     *
     * @return the associated view configuration
     *
     * @throws JAXBException if xml is malformed
     * @throws IOException if xml can not be read
     * @throws SAXException if the validation fails
     */
    public ViewConfig getViewConfigFromExtractedArchive(String archivePath, boolean validate)
        throws JAXBException, IOException, SAXException {
      File configFile = new File(archivePath + File.separator + VIEW_XML);
  
      if (!configFile.exists()) {
        configFile = new File(archivePath + File.separator + WEB_INF_VIEW_XML);
      }
  
      if (validate) {
        validateConfig(new FileInputStream(configFile));
      }
  
      InputStream  configStream = new FileInputStream(configFile);
      try {
  
        JAXBContext  jaxbContext      = JAXBContext.newInstance(ViewConfig.class);
        Unmarshaller jaxbUnmarshaller = jaxbContext.createUnmarshaller();
  
        return (ViewConfig) jaxbUnmarshaller.unmarshal(configStream);
      } finally {
        configStream.close();
      }
    }
  
    /**
     * Get a new file instance for the given path.
     *
     * @param path  the path
     *
     * @return a new file instance
     */
    public File getFile(String path) {
      return new File(path);
    }
  
    /**
     * Get a new file output stream for the given file.
     *
     * @param file  the file
     *
     * @return a new file output stream
     */
    public FileOutputStream getFileOutputStream(File file) throws FileNotFoundException {
      return new FileOutputStream(file);
    }
  
    /**
     * Get a new jar file stream from the given file.
     *
     * @param file  the file
     *
     * @return a new jar file stream
     */
    public JarInputStream getJarFileStream(File file) throws IOException {
      return new JarInputStream(new FileInputStream(file));
    }
  
  
    // ----- helper methods ----------------------------------------------------
  
    /**
     * Validate the given view descriptor file against the view schema.
     *
     * @param configStream  input stream of view descriptor file to be validated
     *
     * @throws SAXException if the validation fails
     * @throws IOException if the descriptor file can not be read
     */
    protected void validateConfig(InputStream  configStream) throws SAXException, IOException {
      SchemaFactory schemaFactory = SchemaFactory.newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
  
      URL schemaUrl = getClass().getClassLoader().getResource(VIEW_XSD);
      Schema schema = schemaFactory.newSchema(schemaUrl);
  
      schema.newValidator().validate(new StreamSource(configStream));
    }
  }
  