org.apache.hudi.common.util.StringUtils Maven / Gradle / Ivy
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing,
* software distributed under the License is distributed on an
* "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
* KIND, either express or implied. See the License for the
* specific language governing permissions and limitations
* under the License.
*/
package org.apache.hudi.common.util;
import javax.annotation.Nullable;
import java.nio.ByteBuffer;
import java.nio.charset.StandardCharsets;
import java.util.Collections;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;
/**
* Simple utility for operations on strings.
*/
public class StringUtils {
public static final char[] HEX_CHAR = new char[] {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
public static final String EMPTY_STRING = "";
// Represents a failed index search
public static final int INDEX_NOT_FOUND = -1;
/**
*
* 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"
*
*/
public static String join(final String... elements) {
return join(elements, EMPTY_STRING);
}
public static String joinUsingDelim(String delim, final String... elements) {
return join(elements, delim);
}
public static String join(final String[] array, final String separator) {
if (array == null) {
return null;
}
return String.join(separator, array);
}
/**
* Wrapper of {@link java.lang.String#join(CharSequence, Iterable)}.
*
* Allow return {@code null} when {@code Iterable} is {@code null}.
*/
public static String join(CharSequence delimiter, Iterable elements) {
if (elements == null) {
return null;
}
return String.join(delimiter, elements);
}
public static String join(final List list, final String separator) {
if (list == null || list.size() == 0) {
return null;
}
return String.join(separator, list.toArray(new String[0]));
}
public static String toHexString(byte[] bytes) {
return new String(encodeHex(bytes));
}
public static char[] encodeHex(byte[] data) {
int l = data.length;
char[] out = new char[l << 1];
int i = 0;
for (int var4 = 0; i < l; ++i) {
out[var4++] = HEX_CHAR[(240 & data[i]) >>> 4];
out[var4++] = HEX_CHAR[15 & data[i]];
}
return out;
}
public static byte[] getUTF8Bytes(String str) {
return str.getBytes(StandardCharsets.UTF_8);
}
public static String fromUTF8Bytes(byte[] bytes) {
return fromUTF8Bytes(bytes, 0, bytes.length);
}
public static String fromUTF8Bytes(byte[] bytes,
int offset,
int length) {
if (bytes == null) {
return null;
}
if (length == 0) {
return "";
}
return new String(bytes, offset, length, StandardCharsets.UTF_8);
}
public static boolean isNullOrEmpty(String str) {
return str == null || str.length() == 0;
}
public static boolean nonEmpty(String str) {
return !isNullOrEmpty(str);
}
/**
* Returns the given string if it is non-null; the empty string otherwise.
*
* @param string the string to test and possibly return
* @return {@code string} itself if it is non-null; {@code ""} if it is null
*/
public static String nullToEmpty(@Nullable String string) {
return string == null ? "" : string;
}
public static String objToString(@Nullable Object obj) {
if (obj == null) {
return null;
}
return obj instanceof ByteBuffer ? toHexString(((ByteBuffer) obj).array()) : obj.toString();
}
/**
* Returns the given string if it is nonempty; {@code null} otherwise.
*
* @param string the string to test and possibly return
* @return {@code string} itself if it is nonempty; {@code null} if it is empty or null
*/
public static @Nullable String emptyToNull(@Nullable String string) {
return stringIsNullOrEmpty(string) ? null : string;
}
private static boolean stringIsNullOrEmpty(@Nullable String string) {
return string == null || string.isEmpty();
}
/**
* Splits input string, delimited {@code delimiter} into a list of non-empty strings
* (skipping any empty string produced during splitting)
*/
public static List split(@Nullable String input, String delimiter) {
if (isNullOrEmpty(input)) {
return Collections.emptyList();
}
return Stream.of(input.split(delimiter)).map(String::trim).filter(s -> !s.isEmpty()).collect(Collectors.toList());
}
public static String getSuffixBy(String input, int ch) {
int i = input.lastIndexOf(ch);
if (i == -1) {
return input;
}
return input.substring(i);
}
public static String removeSuffixBy(String input, int ch) {
int i = input.lastIndexOf(ch);
if (i == -1) {
return input;
}
return input.substring(0, i);
}
public static String truncate(String str, int headLength, int tailLength) {
if (isNullOrEmpty(str) || str.length() <= headLength + tailLength) {
return str;
}
String head = str.substring(0, headLength);
String tail = str.substring(str.length() - tailLength);
return head + "..." + tail;
}
/**
* Compares two version name strings using maven's ComparableVersion class.
*
* @param version1 the first version to compare
* @param version2 the second version to compare
* @return 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.
*/
public static int compareVersions(String version1, String version2) {
ComparableVersion v1 = new ComparableVersion(version1);
ComparableVersion v2 = new ComparableVersion(version2);
return v1.compareTo(v2);
}
/**
* 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.
*
* @param text text to search and replace in, may be null
* @param searchString the String to search for, may be null
* @param replacement the String to replace it with, may be null
* @return the text with any replacements processed,
* null if null String input
* @see #replace(String text, String searchString, String replacement, int max)
*/
public static String replace(String text, String searchString, String replacement) {
return replace(text, searchString, replacement, -1);
}
/**
* 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.
*
* @param text text to search and replace in, may be null
* @param searchString the String to search for, may be null
* @param replacement the String to replace it with, may be null
* @param max maximum number of values to replace, or -1 if no maximum
* @return the text with any replacements processed,
* null if null String input
*/
public static String replace(String text, String searchString, String replacement, int max) {
if (isNullOrEmpty(text) || isNullOrEmpty(searchString) || replacement == null || max == 0) {
return text;
}
int start = 0;
int end = text.indexOf(searchString, start);
if (end == INDEX_NOT_FOUND) {
return text;
}
int replLength = searchString.length();
int increase = replacement.length() - replLength;
increase = (increase < 0 ? 0 : increase);
increase *= (max < 0 ? 16 : (max > 64 ? 64 : max));
StringBuilder buf = new StringBuilder(text.length() + increase);
while (end != INDEX_NOT_FOUND) {
buf.append(text.substring(start, end)).append(replacement);
start = end + replLength;
if (--max == 0) {
break;
}
end = text.indexOf(searchString, start);
}
buf.append(text.substring(start));
return buf.toString();
}
/**
* Strips given characters from end of the string and returns the result
* @param str - string to be stripped
* @param stripChars - characters to strip
*/
public static String stripEnd(final String str, final String stripChars) {
int end;
if (str == null || (end = str.length()) == 0) {
return str;
}
if (stripChars == null) {
while (end != 0 && Character.isWhitespace(str.charAt(end - 1))) {
end--;
}
} else if (stripChars.isEmpty()) {
return str;
} else {
while (end != 0 && stripChars.indexOf(str.charAt(end - 1)) != INDEX_NOT_FOUND) {
end--;
}
}
return str.substring(0, end);
}
}