/**
     * Resolves file: URIs relative to the build file.
     *
     * @param publicId The public identifier, or <code>null</code> if none is available. Ignored in
     *     this implementation.
     * @param systemId The system identifier provided in the XML document. Will not be <code>null
     *     </code>.
     * @return an inputsource for this identifier
     */
    public InputSource resolveEntity(String publicId, String systemId) {

      context.getProject().log("resolving systemId: " + systemId, Project.MSG_VERBOSE);

      if (systemId.startsWith("file:")) {
        String path = FILE_UTILS.fromURI(systemId);

        File file = new File(path);
        if (!file.isAbsolute()) {
          file = FILE_UTILS.resolveFile(context.getBuildFileParent(), path);
          context
              .getProject()
              .log(
                  "Warning: '"
                      + systemId
                      + "' in "
                      + context.getBuildFile()
                      + " should be expressed simply as '"
                      + path.replace('\\', '/')
                      + "' for compliance with other XML tools",
                  Project.MSG_WARN);
        }
        context.getProject().log("file=" + file, Project.MSG_DEBUG);
        try {
          InputSource inputSource = new InputSource(new FileInputStream(file));
          inputSource.setSystemId(FILE_UTILS.toURI(file.getAbsolutePath()));
          return inputSource;
        } catch (FileNotFoundException fne) {
          context
              .getProject()
              .log(file.getAbsolutePath() + " could not be found", Project.MSG_WARN);
        }
      }
      // use default if not file or file not found
      context.getProject().log("could not resolve systemId", Project.MSG_DEBUG);
      return null;
    }
  /**
   * Parses the project file, configuring the project as it goes.
   *
   * @param project the current project
   * @param source the xml source
   * @param handler the root handler to use (contains the current context)
   * @exception BuildException if the configuration is invalid or cannot be read
   */
  public void parse(Project project, Object source, RootHandler handler) throws BuildException {

    AntXMLContext context = handler.context;

    File buildFile = null;
    URL url = null;
    String buildFileName = null;

    if (source instanceof File) {
      buildFile = (File) source;
    } else if (source instanceof URL) {
      url = (URL) source;
    } else if (source instanceof Resource) {
      FileProvider fp = (FileProvider) ((Resource) source).as(FileProvider.class);
      if (fp != null) {
        buildFile = fp.getFile();
      } else {
        URLProvider up = (URLProvider) ((Resource) source).as(URLProvider.class);
        if (up != null) {
          url = up.getURL();
        }
      }
    }
    if (buildFile != null) {
      buildFile = FILE_UTILS.normalize(buildFile.getAbsolutePath());
      context.setBuildFile(buildFile);
      buildFileName = buildFile.toString();
    } else if (url != null) {
      try {
        context.setBuildFile((File) null);
        context.setBuildFile(url);
      } catch (java.net.MalformedURLException ex) {
        throw new BuildException(ex);
      }
      buildFileName = url.toString();
    } else {
      throw new BuildException(
          "Source " + source.getClass().getName() + " not supported by this plugin");
    }
    InputStream inputStream = null;
    InputSource inputSource = null;
    ZipFile zf = null;

    try {
      /** SAX 2 style parser used to parse the given file. */
      XMLReader parser = JAXPUtils.getNamespaceXMLReader();

      String uri = null;
      if (buildFile != null) {
        uri = FILE_UTILS.toURI(buildFile.getAbsolutePath());
        inputStream = new FileInputStream(buildFile);
      } else {
        uri = url.toString();
        int pling = -1;
        if (uri.startsWith("jar:file") && (pling = uri.indexOf("!/")) > -1) {
          zf = new ZipFile(org.apache.tools.ant.launch.Locator.fromJarURI(uri), "UTF-8");
          inputStream = zf.getInputStream(zf.getEntry(uri.substring(pling + 1)));
        } else {
          inputStream = url.openStream();
        }
      }

      inputSource = new InputSource(inputStream);
      if (uri != null) {
        inputSource.setSystemId(uri);
      }
      project.log(
          "parsing buildfile "
              + buildFileName
              + " with URI = "
              + uri
              + (zf != null ? " from a zip file" : ""),
          Project.MSG_VERBOSE);

      DefaultHandler hb = handler;

      parser.setContentHandler(hb);
      parser.setEntityResolver(hb);
      parser.setErrorHandler(hb);
      parser.setDTDHandler(hb);
      parser.parse(inputSource);
    } catch (SAXParseException exc) {
      Location location =
          new Location(exc.getSystemId(), exc.getLineNumber(), exc.getColumnNumber());

      Throwable t = exc.getException();
      if (t instanceof BuildException) {
        BuildException be = (BuildException) t;
        if (be.getLocation() == Location.UNKNOWN_LOCATION) {
          be.setLocation(location);
        }
        throw be;
      }
      throw new BuildException(exc.getMessage(), t == null ? exc : t, location);
    } catch (SAXException exc) {
      Throwable t = exc.getException();
      if (t instanceof BuildException) {
        throw (BuildException) t;
      }
      throw new BuildException(exc.getMessage(), t == null ? exc : t);
    } catch (FileNotFoundException exc) {
      throw new BuildException(exc);
    } catch (UnsupportedEncodingException exc) {
      throw new BuildException("Encoding of project file " + buildFileName + " is invalid.", exc);
    } catch (IOException exc) {
      throw new BuildException(
          "Error reading project file " + buildFileName + ": " + exc.getMessage(), exc);
    } finally {
      FileUtils.close(inputStream);
      ZipFile.closeQuietly(zf);
    }
  }