ContentListener.java

package gov.usgs.earthquake.distribution;

import java.io.File;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Iterator;
import java.util.Map;
import java.util.logging.Logger;

import gov.usgs.earthquake.product.Content;
import gov.usgs.earthquake.product.Product;
import gov.usgs.earthquake.product.ProductId;
import gov.usgs.util.Config;
import gov.usgs.util.StreamUtils;

/**
 * A listener that listens for a specific content path.
 *
 * This is intended for users who wish to output specific pieces of product
 * content, such as "quakeml.xml", for products that otherwise meet their
 * configured NotificationListener criteria.
 */
public class ContentListener extends DefaultNotificationListener {

  private static final Logger LOGGER = Logger.getLogger(ContentListener.class.getName());

  /** configuration property for includePaths - output directory. */
  public static final String OUTPUT_DIRECTORY_PROPERTY = "outputDirectory";
  /** property for temporary directory */
  public static final String TEMP_DIRECTORY_PROPERTY = "tempDirectory";
  /** property for output format */
  public static final String OUTPUT_FORMAT_PROPERTY = "outputFormat";

  /** property for default output format */
  public static final String DEFAULT_OUTPUT_FORMAT = "SOURCE_TYPE_CODE_UPDATETIME_PATH";

  /** Directory where content is output. */
  private File outputDirectory = null;

  /**
   * Temporary directory where content is written before moving to
   * outputDirectory, defaults to system temp directory when null.
   */
  private File tempDirectory = null;

  /** Output format for files inside outputDirectory. */
  private String outputFormat = DEFAULT_OUTPUT_FORMAT;

  /** empty constructor for ContentListener */
  public ContentListener() {
  }

  @Override
  public void configure(final Config config) throws Exception {
    super.configure(config);

    if (getIncludePaths().size() == 0) {
      throw new ConfigurationException("[" + getName() + "] ContentListener requires 'includePaths' be non-empty");
    }

    outputDirectory = new File(config.getProperty(OUTPUT_DIRECTORY_PROPERTY));
    LOGGER.config("[" + getName() + "] output directory = " + outputDirectory);

    String tempDirectoryString = config.getProperty(TEMP_DIRECTORY_PROPERTY);
    if (tempDirectoryString != null) {
      tempDirectory = new File(tempDirectoryString);
    }
    LOGGER.config("[" + getName() + "] temp directory = " + tempDirectory);

    outputFormat = config.getProperty(OUTPUT_FORMAT_PROPERTY, DEFAULT_OUTPUT_FORMAT);
    LOGGER.config("[" + getName() + "] output format = " + outputFormat);
  }

  @Override
  public void onProduct(final Product product) throws Exception {
    Map<String, Content> contents = product.getContents();
    Iterator<String> iter = getIncludePaths().iterator();
    while (iter.hasNext()) {
      String path = iter.next();
      Content content = contents.get(path);
      if (content != null) {
        // product has content at this path
        writeContent(product.getId(), path, content);
      }
    }
  }

  /**
   * Generate an output path based on product id and content path.
   *
   * @param id   the product id.
   * @param path the content path.
   * @return relative path to write content within output directory.
   */
  protected String getOutputPath(final ProductId id, final String path) {
    return outputFormat.replace("SOURCE", id.getSource()).replace("TYPE", id.getType()).replace("CODE", id.getCode())
        .replace("UPDATETIME", Long.toString(id.getUpdateTime().getTime())).replace("PATH", path);
  }

  /**
   * Output a product content that was in includePaths.
   *
   * @param id      the product id.
   * @param path    the content path.
   * @param content the content.
   * @throws Exception when unable to output the content.
   */
  protected void writeContent(final ProductId id, final String path, final Content content) throws Exception {
    String outputPath = getOutputPath(id, path);
    if (tempDirectory != null && !tempDirectory.exists()) {
      // make sure parent directories exist
      tempDirectory.mkdirs();
    }
    File tempFile = File.createTempFile(outputPath, null, tempDirectory);

    File outputFile = new File(outputDirectory, outputPath);
    File outputFileParent = outputFile.getParentFile();
    if (!outputFileParent.exists()) {
      // make sure parent directories exist
      outputFileParent.mkdirs();
    }

    // write, then move into place
    InputStream in = null;
    OutputStream out = null;
    try {
      if (!tempFile.getParentFile().exists()) {
        tempFile.getParentFile().mkdirs();
      }
      if (!outputFile.getParentFile().exists()) {
        outputFile.getParentFile().mkdirs();
      }
      in = content.getInputStream();
      out = StreamUtils.getOutputStream(tempFile);
      // write to temp file
      StreamUtils.transferStream(in, out);
      // move to output file
      tempFile.renameTo(outputFile);
    } finally {
      StreamUtils.closeStream(in);
      StreamUtils.closeStream(out);
      // clean up temp file if it wasn't renamed
      if (tempFile.exists()) {
        tempFile.delete();
      }
    }
  }

  /**
   * @return the outputDirectory
   */
  public File getOutputDirectory() {
    return outputDirectory;
  }

  /**
   * @param outputDirectory the outputDirectory to set
   */
  public void setOutputDirectory(File outputDirectory) {
    this.outputDirectory = outputDirectory;
  }

  /**
   * @return the tempDirectory
   */
  public File getTempDirectory() {
    return tempDirectory;
  }

  /**
   * @param tempDirectory the tempDirectory to set
   */
  public void setTempDirectory(File tempDirectory) {
    this.tempDirectory = tempDirectory;
  }

  /**
   * @return the outputFormat
   */
  public String getOutputFormat() {
    return outputFormat;
  }

  /**
   * @param outputFormat the outputFormat to set
   */
  public void setOutputFormat(String outputFormat) {
    this.outputFormat = outputFormat;
  }

}