MonitoringRequestEditor.java

package org.springframework.roo.file.monitor;

import static org.springframework.roo.file.monitor.event.FileOperation.CREATED;
import static org.springframework.roo.file.monitor.event.FileOperation.DELETED;
import static org.springframework.roo.file.monitor.event.FileOperation.RENAMED;
import static org.springframework.roo.file.monitor.event.FileOperation.UPDATED;

import java.beans.PropertyEditor;
import java.beans.PropertyEditorSupport;
import java.io.File;
import java.io.IOException;
import java.util.Collection;
import java.util.HashSet;
import java.util.Set;

import org.apache.commons.lang3.StringUtils;
import org.apache.commons.lang3.Validate;
import org.springframework.roo.file.monitor.event.FileOperation;

/**
 * A {@link PropertyEditor} for {@link MonitoringRequest}s.
 * <p>
 * The syntax expected by the editor is as follows:
 * <p>
 * <code>fullyQualifiedName + "," + fileOperationCodes + {"," + "**"}<code>
 * 
 * <p>
 * Where:
 * <ul>
 * <li>fullyQualifiedName is a {@link File}-resolvable name (required)</li>
 * <li>fileOperationCodes is one or more of characters "C" (for create), "R" (for rename),
 * "U" (for update) and "D" (for delete), as per {@link FileOperation} (required)</li>
 * <li>literal "**" indicates to watch the subtree, which is only valid if the
 * fullyQualifiedName is an existing directory (optional, but can only be used
 * for a directory)</li>
 * </ul>
 * 
 * @author Ben Alex
 * @since 1.0
 */
public class MonitoringRequestEditor extends PropertyEditorSupport {

  private static final FileOperation[] MONITORED_OPERATIONS = {CREATED, RENAMED, UPDATED, DELETED};
  private static final String SUBTREE_WILDCARD = "**";

  /**
   * @return this object in accordance with the string specification given in
   *         the JavaDocs (or null if the object null)
   */
  @Override
  public String getAsText() {
    final MonitoringRequest req = getValue();
    if (req == null) {
      return null;
    }
    final StringBuilder text = new StringBuilder();
    try {
      text.append(req.getFile().getCanonicalPath());
    } catch (final IOException ioe) {
      throw new IllegalStateException("Failure retrieving path for request '" + req + "'", ioe);
    }
    text.append(",");
    for (final FileOperation fileOperation : MONITORED_OPERATIONS) {
      if (req.getNotifyOn().contains(fileOperation)) {
        text.append(fileOperation.name().charAt(0));
      }
    }
    if (req instanceof DirectoryMonitoringRequest) {
      final DirectoryMonitoringRequest dmr = (DirectoryMonitoringRequest) req;
      if (dmr.isWatchSubtree()) {
        text.append(",").append(SUBTREE_WILDCARD);
      }
    }
    return text.toString();
  }

  @Override
  public MonitoringRequest getValue() {
    return (MonitoringRequest) super.getValue();
  }

  private Collection<FileOperation> parseFileOperations(final String fileOperationCodes) {
    final Set<FileOperation> fileOperations = new HashSet<FileOperation>();
    for (final FileOperation fileOperation : MONITORED_OPERATIONS) {
      if (fileOperationCodes.contains(fileOperation.name().substring(0, 1))) {
        fileOperations.add(fileOperation);
      }
    }
    return fileOperations;
  }

  @Override
  public void setAsText(final String text) throws IllegalArgumentException {
    if (StringUtils.isBlank(text)) {
      setValue(null);
      return;
    }

    final String[] segments = StringUtils.split(text, ",");
    Validate.isTrue(segments.length == 2 || segments.length == 3,
        "Text '%s' is invalid for a MonitoringRequest", text);
    final File file = new File(segments[0]);
    Validate.isTrue(file.exists(), "File '%s' does not exist", file);

    final Collection<FileOperation> fileOperations = parseFileOperations(segments[1]);
    Validate.notEmpty(fileOperations,
        "One or more valid operation codes ('CRUD') required for file '%s'", file);

    if (file.isFile()) {
      Validate.isTrue(segments.length == 2, "Can only have two values for file '%s'", file);
      setValue(new FileMonitoringRequest(file, fileOperations));
    } else {
      setValueToDirectoryMonitoringRequest(segments, file, fileOperations);
    }
  }

  private void setValueToDirectoryMonitoringRequest(final String[] segments, final File file,
      final Collection<FileOperation> fileOperations) {
    if (segments.length == 3) {
      Validate
          .isTrue(
              SUBTREE_WILDCARD.equals(segments[2]),
              "The third value for directory '%s' can only be '%s' (or completely remove the third parameter if you do not want to watch the subtree)",
              file, SUBTREE_WILDCARD);
      setValue(new DirectoryMonitoringRequest(file, true, fileOperations));
    } else {
      setValue(new DirectoryMonitoringRequest(file, false, fileOperations));
    }
  }
}