com.hazelcast.util.StringUtil Maven / Gradle / Ivy
/*
* Copyright (c) 2008-2018, Hazelcast, Inc. All Rights Reserved.
*
* Licensed 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 com.hazelcast.util;
import java.nio.charset.Charset;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.List;
import java.util.Locale;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import static java.lang.Character.isLetter;
import static java.lang.Character.isLowerCase;
import static java.lang.Character.toLowerCase;
/**
* Utility class for Strings.
*/
public final class StringUtil {
/**
* UTF-8 Charset
*/
public static final Charset UTF8_CHARSET = Charset.forName("UTF-8");
/**
* Points to the System property 'line.separator'.
*/
public static final String LINE_SEPARATOR = System.getProperty("line.separator");
/**
* LOCALE_INTERNAL is the default locale for string operations and number formatting. Initialized to
* {@code java.util.Locale.US} (US English).
*/
//TODO Use java.util.Locale#ROOT value (language neutral) in Hazelcast 4
public static final Locale LOCALE_INTERNAL = Locale.US;
/**
* Pattern used to tokenize version strings.
*/
public static final Pattern VERSION_PATTERN
= Pattern.compile("^(\\d+)\\.(\\d+)(\\.(\\d+))?(-\\w+(?:-\\d+)?)?(-SNAPSHOT)?$");
private static final String GETTER_PREFIX = "get";
private StringUtil() {
}
/**
* Creates a UTF8_CHARSET string from a byte array.
*
* @param bytes the byte array.
* @param offset the index of the first byte to decode
* @param length the number of bytes to decode
* @return the string created from the byte array.
*/
public static String bytesToString(byte[] bytes, int offset, int length) {
return new String(bytes, offset, length, UTF8_CHARSET);
}
/**
* Creates a UTF8_CHARSET string from a byte array.
*
* @param bytes the byte array.
* @return the string created from the byte array.
*/
public static String bytesToString(byte[] bytes) {
return new String(bytes, UTF8_CHARSET);
}
/**
* Creates a byte array from a string.
*
* @param s the string.
* @return the byte array created from the string.
*/
public static byte[] stringToBytes(String s) {
return s.getBytes(UTF8_CHARSET);
}
/**
* Checks if a string is empty or not.
*
* @param s the string to check.
* @return true if the string is {@code null} or empty, false otherwise
*/
public static boolean isNullOrEmpty(String s) {
if (s == null) {
return true;
}
return s.isEmpty();
}
/**
* Checks if a string is empty or not after trim operation
*
* @param s the string to check.
* @return true if the string is {@code null} or empty, false otherwise
*/
public static boolean isNullOrEmptyAfterTrim(String s) {
if (s == null) {
return true;
}
return s.trim().isEmpty();
}
/**
* HC specific settings, operands etc. use this method.
* Creates an uppercase string from the given string.
*
* @param s the given string
* @return an uppercase string, or {@code null}/empty if the string is {@code null}/empty
*/
public static String upperCaseInternal(String s) {
if (isNullOrEmpty(s)) {
return s;
}
return s.toUpperCase(LOCALE_INTERNAL);
}
/**
* HC specific settings, operands etc. use this method.
* Creates a lowercase string from the given string.
*
* @param s the given string
* @return a lowercase string, or {@code null}/empty if the string is {@code null}/empty
*/
public static String lowerCaseInternal(String s) {
if (isNullOrEmpty(s)) {
return s;
}
return s.toLowerCase(LOCALE_INTERNAL);
}
/**
* Returns a String representation of the time.
*
* This method is not particularly efficient since it generates a ton of litter.
*
* @param timeMillis time in millis
* @return the String
*/
public static String timeToString(long timeMillis) {
DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");
return dateFormat.format(new Date(timeMillis));
}
/**
* Returns a String representation of the time. If time is 0, then 'never' is returned.
*
* This method is not particularly efficient since it generates a ton of litter.
*
* @param timeMillis time in millis
* @return the String
*/
public static String timeToStringFriendly(long timeMillis) {
return timeMillis == 0 ? "never" : timeToString(timeMillis);
}
/**
* Like a String.indexOf but without MIN_SUPPLEMENTARY_CODE_POINT handling
*
* @param input to check the indexOf on
* @param ch character to find the index of
* @param offset offset to start the reading from
* @return index of the character, or -1 if not found
*/
public static int indexOf(String input, char ch, int offset) {
for (int i = offset; i < input.length(); i++) {
if (input.charAt(i) == ch) {
return i;
}
}
return -1;
}
/**
* Like a String.indexOf but without MIN_SUPPLEMENTARY_CODE_POINT handling
*
* @param input to check the indexOf on
* @param ch character to find the index of
* @return index of the character, or -1 if not found
*/
public static int indexOf(String input, char ch) {
return indexOf(input, ch, 0);
}
/**
* Like a String.lastIndexOf but without MIN_SUPPLEMENTARY_CODE_POINT handling
*
* @param input to check the indexOf on
* @param ch character to find the index of
* @param offset offset to start the reading from the end
* @return index of the character, or -1 if not found
*/
public static int lastIndexOf(String input, char ch, int offset) {
for (int i = input.length() - 1 - offset; i >= 0; i--) {
if (input.charAt(i) == ch) {
return i;
}
}
return -1;
}
/**
* Like a String.lastIndexOf but without MIN_SUPPLEMENTARY_CODE_POINT handling
*
* @param input to check the indexOf on
* @param ch character to find the index of
* @return index of the character, or -1 if not found
*/
public static int lastIndexOf(String input, char ch) {
return lastIndexOf(input, ch, 0);
}
/**
* Tokenizes a version string and returns the tokens with the following grouping:
* (1) major version, eg "3"
* (2) minor version, eg "8"
* (3) patch version prefixed with ".", if exists, otherwise {@code null} (eg ".0")
* (4) patch version, eg "0"
* (5) 1st -qualifier, if exists
* (6) -SNAPSHOT qualifier, if exists
* @param version
* @return
*/
public static String[] tokenizeVersionString(String version) {
Matcher matcher = VERSION_PATTERN.matcher(version);
if (matcher.matches()) {
String[] tokens = new String[matcher.groupCount()];
for (int i = 0; i < matcher.groupCount(); i++) {
tokens[i] = matcher.group(i + 1);
}
return tokens;
} else {
return null;
}
}
/**
* Convert getter into a property name
* Example: 'getFoo' is converted into 'foo'
*
* It's written defensively, when output is not a getter then it
* return the original name.
*
* It converters name starting with the get- prefix only. When a getter
* starts with is- prefix (=boolean) then it does not convert it.
*
* @param getterName
* @return property matching the given getter
*/
public static String getterIntoProperty(String getterName) {
if (getterName == null) {
return getterName;
}
int length = getterName.length();
if (!getterName.startsWith(GETTER_PREFIX) || length <= GETTER_PREFIX.length()) {
return getterName;
}
String propertyName = getterName.substring(GETTER_PREFIX.length(), length);
char firstChar = propertyName.charAt(0);
if (isLetter(firstChar)) {
if (isLowerCase(firstChar)) {
//ok, apparently this is not a JavaBean getter, better leave it untouched
return getterName;
}
propertyName = toLowerCase(firstChar) + propertyName.substring(1, propertyName.length());
}
return propertyName;
}
/**
* Trim whitespaces. This method (compared to {@link String#trim()}) doesn't limit to space character.
*
* @param input string to trim
* @return {@code null} if provided value was {@code null}, input with removed leading and trailing whitespaces
*/
public static String trim(String input) {
if (input == null) {
return null;
}
return input.replaceAll("^\\s+|\\s+$", "");
}
/**
* Splits String value with comma "," used as a separator. The whitespaces around values are trimmed.
*
* @param input string to split
* @return {@code null} if provided value was {@code null}, split parts otherwise (trimmed)
*/
public static String[] splitByComma(String input, boolean allowEmpty) {
if (input == null) {
return null;
}
String[] splitWithEmptyValues = trim(input).split("\\s*,\\s*", -1);
return allowEmpty ? splitWithEmptyValues : subraction(splitWithEmptyValues, new String[] { "" });
}
/**
* Returns intersection of given String arrays. If either array is {@code null}, then {@code null} is returned.
*
* @param arr1 first array
* @param arr2 second array
* @return arr1 without values which are not present in arr2
*/
public static String[] intersection(String[] arr1, String[] arr2) {
if (arr1 == null || arr2 == null) {
return null;
}
if (arr1.length == 0 || arr2.length == 0) {
return new String[0];
}
List list = new ArrayList(Arrays.asList(arr1));
list.retainAll(Arrays.asList(arr2));
return list.toArray(new String[list.size()]);
}
/**
* Returns subtraction between given String arrays.
*
* @param arr1 first array
* @param arr2 second array
* @return arr1 without values which are not present in arr2
*/
public static String[] subraction(String[] arr1, String[] arr2) {
if (arr1 == null || arr1.length == 0 || arr2 == null || arr2.length == 0) {
return arr1;
}
List list = new ArrayList(Arrays.asList(arr1));
list.removeAll(Arrays.asList(arr2));
return list.toArray(new String[list.size()]);
}
/**
* Returns true if two strings are equals ignoring the letter case in {@link #LOCALE_INTERNAL} locale.
*
* @param str1 first string to compare
* @param str2 second string to compare
* @return true if the strings are equals ignoring the case
*/
public static boolean equalsIgnoreCase(String str1, String str2) {
return (str1 == null || str2 == null)
? false
: (str1 == str2 || lowerCaseInternal(str1).equals(lowerCaseInternal(str2)));
}
}