apache/hadoop · error · IllegalArgumentException

The data parameter is not a valid base64-encoded string.

Error message

The data parameter is not a valid base64-encoded string.

What it means

Error "The data parameter is not a valid base64-encoded string." thrown in apache/hadoop.

Source

Thrown at hadoop-tools/hadoop-azure/src/main/java/org/apache/hadoop/fs/azurebfs/utils/Base64.java:69

                                                                             */
          41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1 /*
                                                                            * 112- 127
                                                                            */
  };

  /**
   * Decodes a given Base64 string into its corresponding byte array.
   *
   * @param data
   *            the Base64 string, as a <code>String</code> object, to decode
   *
   * @return the corresponding decoded byte array
   * @throws IllegalArgumentException
   *             If the string is not a valid base64 encoded string
   */
  public static byte[] decode(final String data) {
    if (data == null) {
      throw new IllegalArgumentException("The data parameter is not a valid base64-encoded string.");
    }

    int byteArrayLength = 3 * data.length() / 4;

    if (data.endsWith("==")) {
      byteArrayLength -= 2;
    }
    else if (data.endsWith("=")) {
      byteArrayLength -= 1;
    }

    final byte[] retArray = new byte[byteArrayLength];
    int byteDex = 0;
    int charDex = 0;

    for (; charDex < data.length(); charDex += 4) {
      // get 4 chars, convert to 3 bytes
      final int char1 = DECODE_64[(byte) data.charAt(charDex)];

View on GitHub (pinned to 2add963021)

Solutions

1. Provide a valid base64-encoded string as input.
2. Check for URL-safe vs standard base64 alphabet mismatches in the producer.

When it happens

Trigger: Base64 decoding is attempted on input containing non-base64 characters.

Common situations: See trigger scenarios.

AI-assisted analysis of apache/hadoop@2add963021 (2026-08-22). Data as JSON: /api/errors/ce11f4b15d4c05f8. Report an issue: GitHub.