org.apache.flink.util

Class StringValueUtils

java.lang.Object

org.apache.flink.util.StringValueUtils

@PublicEvolving
public final class StringValueUtils
extends Object

Utility class for efficient operations on StringValue.

All methods in this class are written to be optimized for efficiency and work directly on the StringValues char arrays, avoiding copies. For simplicity and efficiency, the methods only apply to strings whose characters are representable in a single char, ie. strings without surrogate characters.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	StringValueUtils.WhitespaceTokenizer A tokenizer for string values that uses whitespace characters as token delimiters.

Method Summary

Methods

Modifier and Type	Method and Description
static void	replaceNonWordChars(StringValue string, char replacement) Replaces all non-word characters in a string by a given character.
static void	toLowerCase(StringValue string) Converts the given StringValue into a lower case variant.

Methods inherited from class java.lang.Object

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

Method Detail

toLowerCase

public static void toLowerCase(StringValue string)

Converts the given StringValue into a lower case variant.

Parameters:

string - The string to convert to lower case.

replaceNonWordChars

public static void replaceNonWordChars(StringValue string,
                       char replacement)

Replaces all non-word characters in a string by a given character. The only characters not replaced are the characters that qualify as word characters or digit characters with respect to Character.isLetter(char) or Character.isDigit(char), as well as the underscore character.

This operation is intended to simplify strings for counting distinct words.

Parameters:

string - The string value to have the non-word characters replaced.

replacement - The character to use as the replacement.