content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.master.file.meta.xattr;
  
  /**
   * Extend this class to implement any extended attributes.
   *
   * @param <T> The type which the attribute should encode from, and decode to
   */
  public abstract class AbstractExtendedAttribute<T> implements ExtendedAttribute<T> {
    private static final String SEPARATOR = ".";
  
    private final NamespacePrefix mPrefix;
    private final String mIdentifier;
    private final String mFullName;
  
    AbstractExtendedAttribute(NamespacePrefix prefix, String identifier) {
      mPrefix = prefix;
      mIdentifier = identifier;
      mFullName = buildAttr(prefix.toString(), identifier);
    }
  
    @Override
    public String getName() {
      return mFullName;
    }
  
    @Override
    public String getNamespace() {
      return mPrefix.toString();
    }
  
    @Override
    public String getIdentifier() {
      return mIdentifier;
    }
  
    /**
     * Builds an attribute by joining namespace components together.
     *
     * @param components the components to join
     * @return the attribute joined by {@link #SEPARATOR}
     */
    private static String buildAttr(String... components) {
      return String.join(SEPARATOR, components);
    }
  }
  