import org.apache.hadoop.mapreduce.v2.api.MRClientProtocolPB; //导入依赖的package包/类
@Override
public TokenInfo getTokenInfo(Class<?> protocol, Configuration conf) {
  if (!protocol.equals(MRClientProtocolPB.class)) {
    return null;
  }
  return new TokenInfo() {

    @Override
    public Class<? extends Annotation> annotationType() {
      return null;
    }

    @Override
    public Class<? extends TokenSelector<? extends TokenIdentifier>>
        value() {
      return ClientToAMTokenSelector.class;
    }
  };
}
 

import org.apache.hadoop.mapreduce.v2.api.MRClientProtocolPB; //导入依赖的package包/类
public MRClientProtocolPBClientImpl(long clientVersion, InetSocketAddress addr, Configuration conf) throws IOException {
  RPC.setProtocolEngine(conf, MRClientProtocolPB.class, ProtobufRpcEngine.class);
  proxy = RPC.getProxy(MRClientProtocolPB.class, clientVersion, addr, conf);
}