org.apache.hadoop.security.token.TokenIdentifier Maven / Gradle / Ivy
/**
* 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;
import java.io.IOException;
import java.util.Arrays;
import org.apache.commons.codec.digest.DigestUtils;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.io.DataOutputBuffer;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.io.Writable;
import org.apache.hadoop.security.UserGroupInformation;
/**
* An identifier that identifies a token, may contain public information
* about a token, including its kind (or type).
*/
@InterfaceAudience.Public
@InterfaceStability.Evolving
public abstract class TokenIdentifier implements Writable {
private String trackingId = null;
/**
* Get the token kind
* @return the kind of the token
*/
public abstract Text getKind();
/**
* Get the Ugi with the username encoded in the token identifier
*
* @return the username. null is returned if username in the identifier is
* empty or null.
*/
public abstract UserGroupInformation getUser();
/**
* Get the bytes for the token identifier
* @return the bytes of the identifier
*/
public byte[] getBytes() {
DataOutputBuffer buf = new DataOutputBuffer(4096);
try {
this.write(buf);
} catch (IOException ie) {
throw new RuntimeException("i/o error in getBytes", ie);
}
return Arrays.copyOf(buf.getData(), buf.getLength());
}
/**
* Returns a tracking identifier that can be used to associate usages of a
* token across multiple client sessions.
*
* Currently, this function just returns an MD5 of {{@link #getBytes()}.
*
* @return tracking identifier
*/
public String getTrackingId() {
if (trackingId == null) {
trackingId = DigestUtils.md5Hex(getBytes());
}
return trackingId;
}
}