org.apache.lucene.util

Class StringHelper

    • Method Detail

      • bytesDifference

        public static int bytesDifference(BytesRef left,
                                          BytesRef right)
        Compares two BytesRef, element by element, and returns the number of elements common to both arrays (from the start of each).
        Parameters:
        left - The first BytesRef to compare
        right - The second BytesRef to compare
        Returns:
        The number of common elements (from the start of each).
      • startsWith

        public static boolean startsWith(byte[] ref,
                                         BytesRef prefix)
        Returns true iff the ref starts with the given prefix. Otherwise false.
        Parameters:
        ref - the byte[] to test
        prefix - the expected prefix
        Returns:
        Returns true iff the ref starts with the given prefix. Otherwise false.
      • startsWith

        public static boolean startsWith(BytesRef ref,
                                         BytesRef prefix)
        Returns true iff the ref starts with the given prefix. Otherwise false.
        Parameters:
        ref - the BytesRef to test
        prefix - the expected prefix
        Returns:
        Returns true iff the ref starts with the given prefix. Otherwise false.
      • endsWith

        public static boolean endsWith(BytesRef ref,
                                       BytesRef suffix)
        Returns true iff the ref ends with the given suffix. Otherwise false.
        Parameters:
        ref - the BytesRef to test
        suffix - the expected suffix
        Returns:
        Returns true iff the ref ends with the given suffix. Otherwise false.
      • murmurhash3_x86_32

        public static int murmurhash3_x86_32(byte[] data,
                                             int offset,
                                             int len,
                                             int seed)
        Returns the MurmurHash3_x86_32 hash. Original source/tests at https://github.com/yonik/java_util/
      • randomId

        public static byte[] randomId()
        Generates a non-cryptographic globally unique id.
      • idToString

        public static String idToString(byte[] id)
        Helper method to render an ID as a string, for debugging

        Returns the string (null) if the id is null. Otherwise, returns a string representation for debugging. Never throws an exception. The returned string may indicate if the id is definitely invalid.

      • intsRefToBytesRef

        public static BytesRef intsRefToBytesRef(IntsRef ints)
        Just converts each int in the incoming IntsRef to each byte in the returned BytesRef, throwing IllegalArgumentException if any int value is out of bounds for a byte.
      • compare

        public static int compare(int count,
                                  byte[] a,
                                  int aOffset,
                                  byte[] b,
                                  int bOffset)
        Compares a fixed length slice of two byte arrays interpreted as big-endian unsigned values. Returns positive int if a > b, negative int if a < b and 0 if a == b