org.apache.hudi.common.util

Class StringUtils

java.lang.Object

org.apache.hudi.common.util.StringUtils

public class StringUtils
extends Object

Simple utility for operations on strings.

Field Summary

Fields

Modifier and Type	Field and Description
static String	EMPTY_STRING
static char[]	HEX_CHAR
static int	INDEX_NOT_FOUND

Constructor Summary

Constructors

Constructor and Description
StringUtils()

Method Summary

Modifier and Type	Method and Description
static int	compareVersions(String version1, String version2) Compares two version name strings using maven's ComparableVersion class.
static String	concatenateWithThreshold(String a, String b, int byteLengthThreshold) Concatenates two strings such that the total byte length does not exceed the threshold.
static String	emptyToNull(String string) Returns the given string if it is nonempty; null otherwise.
static char[]	encodeHex(byte[] data)
static String	fromUTF8Bytes(byte[] bytes)
static String	fromUTF8Bytes(byte[] bytes, int offset, int length)
static String	getSuffixBy(String input, int ch)
static byte[]	getUTF8Bytes(String str)
static boolean	isNullOrEmpty(String str)
static String	join(CharSequence delimiter, Iterable<? extends CharSequence> elements) Wrapper of String.join(CharSequence, Iterable).
static String	join(List<String> list, String separator)
static <K,V> String	join(Map<K,V> map)
static <T> String	join(String... elements) Joins the elements of the provided array into a single String containing the provided list of elements.
static String	join(String[] array, String separator)
static <T> String	joinUsingDelim(String delim, String... elements)
static boolean	nonEmpty(String str)
static String	nullToEmpty(String string) Returns the given string if it is non-null; the empty string otherwise.
static String	objToString(Object obj)
static String	removeSuffixBy(String input, int ch)
static String	replace(String text, String searchString, String replacement) Replaces all occurrences of a String within another String.
static String	replace(String text, String searchString, String replacement, int max) Replaces a String with another String inside a larger String, for the first max values of the search String.
static List<String>	split(String input, String delimiter) Splits input string, delimited delimiter into a list of non-empty strings (skipping any empty string produced during splitting)
static String	stripEnd(String str, String stripChars) Strips given characters from end of the string and returns the result
static String	toHexString(byte[] bytes)
static <T> String	toStringWithThreshold(List<T> objectList, int lengthThreshold) Concatenates the string representation of each object in the list and returns a single string.
static String	truncate(String str, int headLength, int tailLength)

Methods inherited from class java.lang.Object

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

Field Detail

HEX_CHAR

public static final char[] HEX_CHAR

EMPTY_STRING

public static final String EMPTY_STRING

See Also:

Constant Field Values

INDEX_NOT_FOUND

public static final int INDEX_NOT_FOUND

See Also:

Constant Field Values

Constructor Detail

StringUtils

public StringUtils()

Method Detail

join

public static <T> String join(String... elements)

Joins the elements of the provided array into a single String containing the provided list of elements.

No separator is added to the joined String. Null objects or empty strings within the array are represented by empty strings.

 StringUtils.join(null)            = null
 StringUtils.join([])              = ""
 StringUtils.join([null])          = ""
 StringUtils.join(["a", "b", "c"]) = "abc"
 StringUtils.join([null, "", "a"]) = "a"
 

joinUsingDelim

public static <T> String joinUsingDelim(String delim,
                                        String... elements)

join

public static String join(String[] array,
                          String separator)

join

public static String join(CharSequence delimiter,
                          Iterable<? extends CharSequence> elements)

Wrapper of String.join(CharSequence, Iterable). Allow return null when Iterable is null.

join

public static String join(List<String> list,
                          String separator)

join

public static <K,V> String join(Map<K,V> map)

toHexString

public static String toHexString(byte[] bytes)

encodeHex

public static char[] encodeHex(byte[] data)

getUTF8Bytes

public static byte[] getUTF8Bytes(String str)

fromUTF8Bytes

public static String fromUTF8Bytes(byte[] bytes)

fromUTF8Bytes

public static String fromUTF8Bytes(byte[] bytes,
                                   int offset,
                                   int length)

isNullOrEmpty

public static boolean isNullOrEmpty(String str)

nonEmpty

public static boolean nonEmpty(String str)

nullToEmpty

public static String nullToEmpty(@Nullable
                                 String string)

Returns the given string if it is non-null; the empty string otherwise.

Parameters:

string - the string to test and possibly return

Returns:

string itself if it is non-null; "" if it is null

objToString

public static String objToString(@Nullable
                                 Object obj)

emptyToNull

@Nullable
public static String emptyToNull(@Nullable
                                           String string)

Returns the given string if it is nonempty; null otherwise.

Parameters:

string - the string to test and possibly return

Returns:

string itself if it is nonempty; null if it is empty or null

split

public static List<String> split(@Nullable
                                 String input,
                                 String delimiter)

Splits input string, delimited delimiter into a list of non-empty strings (skipping any empty string produced during splitting)

getSuffixBy

public static String getSuffixBy(String input,
                                 int ch)

removeSuffixBy

public static String removeSuffixBy(String input,
                                    int ch)

truncate

public static String truncate(String str,
                              int headLength,
                              int tailLength)

compareVersions

public static int compareVersions(String version1,
                                  String version2)

Compares two version name strings using maven's ComparableVersion class.

Parameters:

version1 - the first version to compare

version2 - the second version to compare

Returns:

a negative integer if version1 precedes version2, a positive integer if version2 precedes version1, and 0 if and only if the two versions are equal.

replace

public static String replace(String text,
                             String searchString,
                             String replacement)

Replaces all occurrences of a String within another String.

A null reference passed to this method is a no-op.

 StringUtils.replace(null, *, *)        = null
 StringUtils.replace("", *, *)          = ""
 StringUtils.replace("any", null, *)    = "any"
 StringUtils.replace("any", *, null)    = "any"
 StringUtils.replace("any", "", *)      = "any"
 StringUtils.replace("aba", "a", null)  = "aba"
 StringUtils.replace("aba", "a", "")    = "b"
 StringUtils.replace("aba", "a", "z")   = "zbz"
 

This method is copied from hadoop StringUtils.

Parameters:

text - text to search and replace in, may be null

searchString - the String to search for, may be null

replacement - the String to replace it with, may be null

Returns:

the text with any replacements processed, null if null String input

See Also:

replace(String text, String searchString, String replacement, int max)

replace

public static String replace(String text,
                             String searchString,
                             String replacement,
                             int max)

Replaces a String with another String inside a larger String, for the first max values of the search String.

A null reference passed to this method is a no-op.

 StringUtils.replace(null, *, *, *)         = null
 StringUtils.replace("", *, *, *)           = ""
 StringUtils.replace("any", null, *, *)     = "any"
 StringUtils.replace("any", *, null, *)     = "any"
 StringUtils.replace("any", "", *, *)       = "any"
 StringUtils.replace("any", *, *, 0)        = "any"
 StringUtils.replace("abaa", "a", null, -1) = "abaa"
 StringUtils.replace("abaa", "a", "", -1)   = "b"
 StringUtils.replace("abaa", "a", "z", 0)   = "abaa"
 StringUtils.replace("abaa", "a", "z", 1)   = "zbaa"
 StringUtils.replace("abaa", "a", "z", 2)   = "zbza"
 StringUtils.replace("abaa", "a", "z", -1)  = "zbzz"
 

This method is copied from hadoop StringUtils.

Parameters:

text - text to search and replace in, may be null

searchString - the String to search for, may be null

replacement - the String to replace it with, may be null

max - maximum number of values to replace, or -1 if no maximum

Returns:

the text with any replacements processed, null if null String input

stripEnd

public static String stripEnd(String str,
                              String stripChars)

Strips given characters from end of the string and returns the result

Parameters:

str - - string to be stripped

stripChars - - characters to strip

concatenateWithThreshold

public static String concatenateWithThreshold(String a,
                                              String b,
                                              int byteLengthThreshold)

Concatenates two strings such that the total byte length does not exceed the threshold. If the total byte length exceeds the threshold, the function will find the maximum length of the first string that fits within the threshold and concatenate that with the second string.

Parameters:

a - The first string

b - The second string

byteLengthThreshold - The maximum byte length

toStringWithThreshold

public static <T> String toStringWithThreshold(List<T> objectList,
                                               int lengthThreshold)

Concatenates the string representation of each object in the list and returns a single string. The result is capped at "lengthThreshold" characters.

Type Parameters:

T - type of the object

Parameters:

objectList - object list

lengthThreshold - number of characters to cap the string

Returns:

capped string representation of the object list