FileEvent.java

package org.springframework.roo.file.monitor.event;

import java.io.File;

import org.apache.commons.lang3.Validate;
import org.apache.commons.lang3.builder.ToStringBuilder;

/**
 * Represents a file notification message.
 * <p>
 * There are three types of file event notifications:
 * <ul>
 * <li>An event with {@link FileOperation#MONITORING_START} when a file is first
 * detected on the disk and will be monitored.</li>
 * <li>An event with {@link FileOperation#MONITORING_FINISH} when a file that
 * has been monitored is no longer going to be monitored.</li>
 * <li>An event with any other {@link FileOperation} code when the file is
 * created, updated, deleted or (if available) renamed.</li>
 * </ul>
 * 
 * @author Ben Alex
 * @since 1.0
 */
public class FileEvent {
  private final FileDetails fileDetails;
  private final FileOperation operation;
  private final File previousName;

  public FileEvent(final FileDetails fileDetails, final FileOperation operation,
      final File previousName) {
    Validate.notNull(fileDetails, "File details required");
    Validate.notNull(operation, "File operation required");
    this.fileDetails = fileDetails;
    this.operation = operation;
    this.previousName = previousName;
  }

  /**
   * @return the file that is subject of this event (never null).
   */
  public FileDetails getFileDetails() {
    return fileDetails;
  }

  /**
   * @return the file operation being performed (never null).
   */
  public FileOperation getOperation() {
    return operation;
  }

  /**
   * If supported by the implementation, indicates the old name of the
   * resource. Implementations are not required to support rename
   * notifications.
   * 
   * @return the old name of the file being {@link FileOperation#RENAMED}
   *         (will be null if not a rename notification).
   */
  public File getPreviousName() {
    return previousName;
  }

  @Override
  public String toString() {
    final ToStringBuilder builder = new ToStringBuilder(this);
    builder.append("fileDetails", fileDetails);
    builder.append("operation", operation);
    builder.append("previousName", previousName);
    return builder.toString();
  }

}