org.apache.lucene.util

Class StringHelper

java.lang.Object

org.apache.lucene.util.StringHelper

public abstract class StringHelper
extends Object

Methods for manipulating strings.

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

Field Summary

Fields

Modifier and Type	Field and Description
static int	GOOD_FAST_HASH_SEED Pass this as the seed to murmurhash3_x86_32(byte[], int, int, int).

Method Summary

Methods

Modifier and Type	Method and Description
static int	bytesDifference(BytesRef left, BytesRef right) Compares two BytesRef, element by element, and returns the number of elements common to both arrays.
static boolean	endsWith(BytesRef ref, BytesRef suffix) Returns true iff the ref ends with the given suffix.
static boolean	equals(String s1, String s2)
static Comparator<String>	getVersionComparator()
static int	murmurhash3_x86_32(byte[] data, int offset, int len, int seed) Returns the MurmurHash3_x86_32 hash.
static int	murmurhash3_x86_32(BytesRef bytes, int seed)
static boolean	startsWith(BytesRef ref, BytesRef prefix) Returns true iff the ref starts with the given prefix.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

GOOD_FAST_HASH_SEED

public static final int GOOD_FAST_HASH_SEED

Pass this as the seed to murmurhash3_x86_32(byte[], int, int, int).

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.

Parameters:

left - The first BytesRef to compare

right - The second BytesRef to compare

Returns:

The number of common elements.

getVersionComparator

public static Comparator<String> getVersionComparator()

Returns:

a Comparator over versioned strings such as X.YY.Z

NOTE: This API is for internal purposes only and might change in incompatible ways in the next release.

equals

public static boolean equals(String s1,
             String s2)

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/

murmurhash3_x86_32

public static int murmurhash3_x86_32(BytesRef bytes,
                     int seed)