import org.apache.hadoop.crypto.key.KeyProviderDelegationTokenExtension; //导入依赖的package包/类
@Override
public Token<?>[] addDelegationTokens(
    final String renewer, Credentials credentials) throws IOException {
  Token<?>[] tokens = super.addDelegationTokens(renewer, credentials);
  if (dfs.isHDFSEncryptionEnabled()) {
    KeyProviderDelegationTokenExtension keyProviderDelegationTokenExtension =
        KeyProviderDelegationTokenExtension.
            createKeyProviderDelegationTokenExtension(dfs.getKeyProvider());
    Token<?>[] kpTokens = keyProviderDelegationTokenExtension.
        addDelegationTokens(renewer, credentials);
    if (tokens != null && kpTokens != null) {
      Token<?>[] all = new Token<?>[tokens.length + kpTokens.length];
      System.arraycopy(tokens, 0, all, 0, tokens.length);
      System.arraycopy(kpTokens, 0, all, tokens.length, kpTokens.length);
      tokens = all;
    } else {
      tokens = (tokens != null) ? tokens : kpTokens;
    }
  }
  return tokens;
}
 

import org.apache.hadoop.crypto.key.KeyProviderDelegationTokenExtension; //导入依赖的package包/类
@Override
public Token<?>[] addDelegationTokens(
    final String renewer, Credentials credentials) throws IOException {
  Token<?>[] tokens = super.addDelegationTokens(renewer, credentials);
  if (dfs.getKeyProvider() != null) {
    KeyProviderDelegationTokenExtension keyProviderDelegationTokenExtension =
        KeyProviderDelegationTokenExtension.
            createKeyProviderDelegationTokenExtension(dfs.getKeyProvider());
    Token<?>[] kpTokens = keyProviderDelegationTokenExtension.
        addDelegationTokens(renewer, credentials);
    if (tokens != null && kpTokens != null) {
      Token<?>[] all = new Token<?>[tokens.length + kpTokens.length];
      System.arraycopy(tokens, 0, all, 0, tokens.length);
      System.arraycopy(kpTokens, 0, all, tokens.length, kpTokens.length);
      tokens = all;
    } else {
      tokens = (tokens != null) ? tokens : kpTokens;
    }
  }
  return tokens;
}
 

import org.apache.hadoop.crypto.key.KeyProviderDelegationTokenExtension; //导入依赖的package包/类
@Override
public long renew(Token<?> token, Configuration conf) throws IOException {
  LOG.debug("Renewing delegation token {}", token);
  KeyProvider keyProvider = KMSUtil.createKeyProvider(conf,
      KeyProviderFactory.KEY_PROVIDER_PATH);
  try {
    if (!(keyProvider instanceof
        KeyProviderDelegationTokenExtension.DelegationTokenExtension)) {
      LOG.warn("keyProvider {} cannot renew dt.", keyProvider == null ?
          "null" : keyProvider.getClass());
      return 0;
    }
    return ((KeyProviderDelegationTokenExtension.DelegationTokenExtension)
        keyProvider).renewDelegationToken(token);
  } finally {
    if (keyProvider != null) {
      keyProvider.close();
    }
  }
}
 

import org.apache.hadoop.crypto.key.KeyProviderDelegationTokenExtension; //导入依赖的package包/类
@Override
public void cancel(Token<?> token, Configuration conf) throws IOException {
  LOG.debug("Canceling delegation token {}", token);
  KeyProvider keyProvider = KMSUtil.createKeyProvider(conf,
      KeyProviderFactory.KEY_PROVIDER_PATH);
  try {
    if (!(keyProvider instanceof
        KeyProviderDelegationTokenExtension.DelegationTokenExtension)) {
      LOG.warn("keyProvider {} cannot cancel dt.", keyProvider == null ?
          "null" : keyProvider.getClass());
      return;
    }
    ((KeyProviderDelegationTokenExtension.DelegationTokenExtension)
        keyProvider).cancelDelegationToken(token);
  } finally {
    if (keyProvider != null) {
      keyProvider.close();
    }
  }
}