import org.apache.hadoop.hdfs.protocolPB.InterDatanodeProtocolTranslatorPB; //导入依赖的package包/类
public static InterDatanodeProtocol createInterDataNodeProtocolProxy(
    DatanodeID datanodeid, final Configuration conf, final int socketTimeout,
    final boolean connectToDnViaHostname) throws IOException {
  final String dnAddr = datanodeid.getIpcAddr(connectToDnViaHostname);
  final InetSocketAddress addr = NetUtils.createSocketAddr(dnAddr);
  if (LOG.isDebugEnabled()) {
    LOG.debug("Connecting to datanode " + dnAddr + " addr=" + addr);
  }
  final UserGroupInformation loginUgi = UserGroupInformation.getLoginUser();
  try {
    return loginUgi
        .doAs(new PrivilegedExceptionAction<InterDatanodeProtocol>() {
          @Override
          public InterDatanodeProtocol run() throws IOException {
            return new InterDatanodeProtocolTranslatorPB(addr, loginUgi,
                conf, NetUtils.getDefaultSocketFactory(conf), socketTimeout);
          }
        });
  } catch (InterruptedException ie) {
    throw new IOException(ie.getMessage());
  }
}
 

import org.apache.hadoop.hdfs.protocolPB.InterDatanodeProtocolTranslatorPB; //导入依赖的package包/类
public static InterDatanodeProtocol createInterDataNodeProtocolProxy(
    DatanodeID datanodeid, final Configuration conf, final int socketTimeout,
    final boolean connectToDnViaHostname) throws IOException {
  final String dnAddr = datanodeid.getIpcAddr(connectToDnViaHostname);
  final InetSocketAddress addr = NetUtils.createSocketAddr(dnAddr);
  if (LOG.isDebugEnabled()) {
    LOG.debug("Connecting to datanode " + dnAddr + " addr=" + addr);
  }
  final UserGroupInformation loginUgi = UserGroupInformation.getLoginUser();
  try {
    return loginUgi
        .doAs(new PrivilegedExceptionAction<InterDatanodeProtocol>() {
          @Override
          public InterDatanodeProtocol run() throws IOException {
            return new InterDatanodeProtocolTranslatorPB(addr, loginUgi, conf,
                NetUtils.getDefaultSocketFactory(conf), socketTimeout);
          }
        });
  } catch (InterruptedException ie) {
    throw new IOException(ie.getMessage());
  }
}