001/**
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018
019package org.apache.hadoop.yarn.security.client;
020
021import java.util.Collection;
022
023import org.apache.commons.logging.Log;
024import org.apache.commons.logging.LogFactory;
025import org.apache.hadoop.classification.InterfaceAudience.Public;
026import org.apache.hadoop.classification.InterfaceStability.Evolving;
027import org.apache.hadoop.io.Text;
028import org.apache.hadoop.security.token.Token;
029import org.apache.hadoop.security.token.TokenIdentifier;
030import org.apache.hadoop.security.token.TokenSelector;
031
032@Public
033@Evolving
034public class TimelineDelegationTokenSelector
035    implements TokenSelector<TimelineDelegationTokenIdentifier> {
036
037  private static final Log LOG = LogFactory
038      .getLog(TimelineDelegationTokenSelector.class);
039
040  @SuppressWarnings("unchecked")
041  public Token<TimelineDelegationTokenIdentifier> selectToken(Text service,
042      Collection<Token<? extends TokenIdentifier>> tokens) {
043    if (service == null) {
044      return null;
045    }
046    if (LOG.isDebugEnabled()) {
047      LOG.debug("Looking for a token with service " + service.toString());
048    }
049    for (Token<? extends TokenIdentifier> token : tokens) {
050      if (LOG.isDebugEnabled()) {
051        LOG.debug("Token kind is " + token.getKind().toString()
052            + " and the token's service name is " + token.getService());
053      }
054      if (TimelineDelegationTokenIdentifier.KIND_NAME.equals(token.getKind())
055          && service.equals(token.getService())) {
056        return (Token<TimelineDelegationTokenIdentifier>) token;
057      }
058    }
059    return null;
060  }
061
062}