org.apache.hadoop.security.token.delegation.AbstractDelegationTokenSelector.java Source code

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Here is the source code for org.apache.hadoop.security.token.delegation.AbstractDelegationTokenSelector.java

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/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.hadoop.security.token.delegation;

import java.util.Collection;

import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.security.token.Token;
import org.apache.hadoop.security.token.TokenIdentifier;
import org.apache.hadoop.security.token.TokenSelector;

/**
 * Look through tokens to find the first delegation token that matches the
 * service and return it.
 */
@InterfaceAudience.LimitedPrivate({ "HDFS", "MapReduce" })
@InterfaceStability.Evolving
public class AbstractDelegationTokenSelector<TokenIdent extends AbstractDelegationTokenIdentifier>
        implements TokenSelector<TokenIdent> {
    private Text kindName;

    protected AbstractDelegationTokenSelector(Text kindName) {
        this.kindName = kindName;
    }

    @SuppressWarnings("unchecked")
    @Override
    public Token<TokenIdent> selectToken(Text service, Collection<Token<? extends TokenIdentifier>> tokens) {
        if (service == null) {
            return null;
        }
        for (Token<? extends TokenIdentifier> token : tokens) {
            if (kindName.equals(token.getKind()) && service.equals(token.getService())) {
                return (Token<TokenIdent>) token;
            }
        }
        return null;
    }
}