[HBASE-6991] Escape "\" in Bytes.toStringBinary() and its counterpart Bytes.toBytesBinary()

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.95.2
• Fix Version/s: 0.95.0
• Component/s: util
• Hadoop Flags: Incompatible change, Reviewed

Release Note

This patch changes Bytes.toStringBinary() and Bytes.toBytesBinary() to escape the character "\". Unprintable characters are escaped using "\\x%02X" format, but "\" was not escaped properly leading to irreversible ser/de using toStringBinary() -> toBytesBinary().

• Assignee: Aditya Kishore
• Reporter: Aditya Kishore
• Created: 13/Oct/12 10:29
• Updated: 23/Sep/13 18:30
• Resolved: 06/Nov/12 20:09

Description

Since "\" is used to escape non-printable character but not treated as special character in conversion, it could lead to unexpected conversion.

For example, please consider the following code snippet.

public void testConversion() {
  byte[] original = {
      '\\', 'x', 'A', 'D'
  };
  String stringFromBytes = Bytes.toStringBinary(original);
  byte[] converted = Bytes.toBytesBinary(stringFromBytes);
  System.out.println("Original: " + Arrays.toString(original));
  System.out.println("Converted: " + Arrays.toString(converted));
  System.out.println("Reversible?: " + (Bytes.compareTo(original, converted) == 0));
}

Output:
-------
Original: [92, 120, 65, 68]
Converted: [-83]
Reversible?: false

The "\" character needs to be treated as special and must be encoded as a non-printable character ("\x5C") to avoid any kind of ambiguity during conversion.

Issue Links

• is related to: HBASE-8085 Backport the fix for Bytes.toStringBinary() into 94 (HBASE-6991)