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/*
* 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 com.networknt.utility;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.*;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* Majority of the methods are extracted from apache commons-lang to avoid include a
* big jar file into the final package.
*
*/
public class StringUtils {
private static final String[] EMPTY_STRING_ARRAY = {};
private static final int STRING_BUILDER_SIZE = 256;
/**
* Represents a failed index search.
* @since 2.1
*/
public static final int INDEX_NOT_FOUND = -1;
/**
* The empty String {@code ""}.
* @since 2.0
*/
public static final String EMPTY = "";
/**
* A String for a space character.
*
* @since 3.2
*/
public static final String SPACE = " ";
public static final String EMAIL_PATTERN = "^[_A-Za-z0-9-\\+]+(\\.[_A-Za-z0-9-]+)*@"
+ "[A-Za-z0-9-]+(\\.[A-Za-z0-9]+)*(\\.[A-Za-z]{2,})$";
public static Pattern pattern = Pattern.compile(EMAIL_PATTERN);
/**
* Check if the string is null or empty
*
* @param value the value that is checked
* @return true if the given value is either null or the empty string
*
*/
public static boolean isNullOrEmpty(String value) {
return value == null || value.isEmpty();
}
public static String expandEnvVars(String text) {
Map envMap = System.getenv();
String pattern = "\\$\\{([A-Za-z0-9-_]+)\\}";
Pattern expr = Pattern.compile(pattern);
Matcher matcher = expr.matcher(text);
while (matcher.find()) {
String envValue = envMap.get(matcher.group(1).toUpperCase());
if (envValue == null) {
envValue = "";
} else {
envValue = envValue.replace("\\", "\\\\");
}
Pattern subexpr = Pattern.compile(Pattern.quote(matcher.group(0)));
text = subexpr.matcher(text).replaceAll(envValue);
}
return text;
}
/**
* Replaces a String with another String inside a larger String,
* for the first {@code max} values of the search String.
*
* A {@code 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"
*
*
* @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 {@code -1} if no maximum
* @return the text with any replacements processed,
* {@code null} if null String input
*/
public static String replace(final String text, final String searchString, final String replacement, final int max) {
return replace(text, searchString, replacement, max, false);
}
/**
* Replaces a String with another String inside a larger String,
* for the first {@code max} values of the search String,
* case sensitively/insensisitively based on {@code ignoreCase} value.
*
* A {@code null} reference passed to this method is a no-op.
*
*
* StringUtils.replace(null, *, *, *, false) = null
* StringUtils.replace("", *, *, *, false) = ""
* StringUtils.replace("any", null, *, *, false) = "any"
* StringUtils.replace("any", *, null, *, false) = "any"
* StringUtils.replace("any", "", *, *, false) = "any"
* StringUtils.replace("any", *, *, 0, false) = "any"
* StringUtils.replace("abaa", "a", null, -1, false) = "abaa"
* StringUtils.replace("abaa", "a", "", -1, false) = "b"
* StringUtils.replace("abaa", "a", "z", 0, false) = "abaa"
* StringUtils.replace("abaa", "A", "z", 1, false) = "abaa"
* StringUtils.replace("abaa", "A", "z", 1, true) = "zbaa"
* StringUtils.replace("abAa", "a", "z", 2, true) = "zbza"
* StringUtils.replace("abAa", "a", "z", -1, true) = "zbzz"
*
*
* @param text text to search and replace in, may be null
* @param searchString the String to search for (case insensitive), may be null
* @param replacement the String to replace it with, may be null
* @param max maximum number of values to replace, or {@code -1} if no maximum
* @param ignoreCase if true replace is case insensitive, otherwise case sensitive
* @return the text with any replacements processed,
* {@code null} if null String input
*/
private static String replace(final String text, String searchString, final String replacement, int max, final boolean ignoreCase) {
if (isEmpty(text) || isEmpty(searchString) || replacement == null || max == 0) {
return text;
}
String searchText = text;
if (ignoreCase) {
searchText = text.toLowerCase();
searchString = searchString.toLowerCase();
}
int start = 0;
int end = searchText.indexOf(searchString, start);
if (end == INDEX_NOT_FOUND) {
return text;
}
final int replLength = searchString.length();
int increase = replacement.length() - replLength;
increase = increase < 0 ? 0 : increase;
increase *= max < 0 ? 16 : max > 64 ? 64 : max;
final StringBuilder buf = new StringBuilder(text.length() + increase);
while (end != INDEX_NOT_FOUND) {
buf.append(text, start, end).append(replacement);
start = end + replLength;
if (--max == 0) {
break;
}
end = searchText.indexOf(searchString, start);
}
buf.append(text, start, text.length());
return buf.toString();
}
// Replacing
/**
* Replaces a String with another String inside a larger String, once.
*
* A {@code null} reference passed to this method is a no-op.
*
*
* StringUtils.replaceOnce(null, *, *) = null
* StringUtils.replaceOnce("", *, *) = ""
* StringUtils.replaceOnce("any", null, *) = "any"
* StringUtils.replaceOnce("any", *, null) = "any"
* StringUtils.replaceOnce("any", "", *) = "any"
* StringUtils.replaceOnce("aba", "a", null) = "aba"
* StringUtils.replaceOnce("aba", "a", "") = "ba"
* StringUtils.replaceOnce("aba", "a", "z") = "zba"
*
*
* @see #replace(String text, String searchString, String replacement, int max)
* @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 with, may be null
* @return the text with any replacements processed,
* {@code null} if null String input
*/
public static String replaceOnce(final String text, final String searchString, final String replacement) {
return replace(text, searchString, replacement, 1);
}
// Empty checks
//-----------------------------------------------------------------------
/**
* Checks if a CharSequence is empty ("") or null.
*
*
* StringUtils.isEmpty(null) = true
* StringUtils.isEmpty("") = true
* StringUtils.isEmpty(" ") = false
* StringUtils.isEmpty("bob") = false
* StringUtils.isEmpty(" bob ") = false
*
*
* NOTE: This method changed in Lang version 2.0.
* It no longer trims the CharSequence.
* That functionality is available in isBlank().
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if the CharSequence is empty or null
* @since 3.0 Changed signature from isEmpty(String) to isEmpty(CharSequence)
*/
public static boolean isEmpty(final CharSequence cs) {
return cs == null || cs.length() == 0;
}
/**
* Right pad a String with a specified character.
*
* The String is padded to the size of {@code size}.
*
*
* StringUtils.rightPad(null, *, *) = null
* StringUtils.rightPad("", 3, 'z') = "zzz"
* StringUtils.rightPad("bat", 3, 'z') = "bat"
* StringUtils.rightPad("bat", 5, 'z') = "batzz"
* StringUtils.rightPad("bat", 1, 'z') = "bat"
* StringUtils.rightPad("bat", -1, 'z') = "bat"
*
*
* @param str the String to pad out, may be null
* @param size the size to pad to
* @param padChar the character to pad with
* @return right padded String or original String if no padding is necessary,
* {@code null} if null String input
* @since 2.0
*/
public static String rightPad(final String str, final int size, final char padChar) {
if (str == null) {
return null;
}
final int pads = size - str.length();
if (pads <= 0) {
return str; // returns original String when possible
}
if (pads > PAD_LIMIT) {
return rightPad(str, size, String.valueOf(padChar));
}
return str.concat(repeat(padChar, pads));
}
/**
* The maximum size to which the padding constant(s) can expand.
*/
private static final int PAD_LIMIT = 8192;
/**
* Returns padding using the specified delimiter repeated
* to a given length.
*
*
* StringUtils.repeat('e', 0) = ""
* StringUtils.repeat('e', 3) = "eee"
* StringUtils.repeat('e', -2) = ""
*
*
* Note: this method does not support padding with
* Unicode Supplementary Characters
* as they require a pair of {@code char}s to be represented.
* If you are needing to support full I18N of your applications
* consider using repeat(String, int) instead.
*
*
* @param ch character to repeat
* @param repeat number of times to repeat char, negative treated as zero
* @return String with repeated character
*/
public static String repeat(final char ch, final int repeat) {
if (repeat <= 0) {
return EMPTY;
}
final char[] buf = new char[repeat];
for (int i = repeat - 1; i >= 0; i--) {
buf[i] = ch;
}
return new String(buf);
}
/**
* Right pad a String with a specified String.
*
* The String is padded to the size of {@code size}.
*
*
* StringUtils.rightPad(null, *, *) = null
* StringUtils.rightPad("", 3, "z") = "zzz"
* StringUtils.rightPad("bat", 3, "yz") = "bat"
* StringUtils.rightPad("bat", 5, "yz") = "batyz"
* StringUtils.rightPad("bat", 8, "yz") = "batyzyzy"
* StringUtils.rightPad("bat", 1, "yz") = "bat"
* StringUtils.rightPad("bat", -1, "yz") = "bat"
* StringUtils.rightPad("bat", 5, null) = "bat "
* StringUtils.rightPad("bat", 5, "") = "bat "
*
*
* @param str the String to pad out, may be null
* @param size the size to pad to
* @param padStr the String to pad with, null or empty treated as single space
* @return right padded String or original String if no padding is necessary,
* {@code null} if null String input
*/
public static String rightPad(final String str, final int size, String padStr) {
if (str == null) {
return null;
}
if (isEmpty(padStr)) {
padStr = SPACE;
}
final int padLen = padStr.length();
final int strLen = str.length();
final int pads = size - strLen;
if (pads <= 0) {
return str; // returns original String when possible
}
if (padLen == 1 && pads <= PAD_LIMIT) {
return rightPad(str, size, padStr.charAt(0));
}
if (pads == padLen) {
return str.concat(padStr);
} else if (pads < padLen) {
return str.concat(padStr.substring(0, pads));
} else {
final char[] padding = new char[pads];
final char[] padChars = padStr.toCharArray();
for (int i = 0; i < pads; i++) {
padding[i] = padChars[i % padLen];
}
return str.concat(new String(padding));
}
}
/**
* Checks if a CharSequence is empty (""), null or whitespace only.
*
* Whitespace is defined by {@link Character#isWhitespace(char)}.
*
*
* StringUtils.isBlank(null) = true
* StringUtils.isBlank("") = true
* StringUtils.isBlank(" ") = true
* StringUtils.isBlank("bob") = false
* StringUtils.isBlank(" bob ") = false
*
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if the CharSequence is null, empty or whitespace only
* @since 2.0
* @since 3.0 Changed signature from isBlank(String) to isBlank(CharSequence)
*/
public static boolean isBlank(final CharSequence cs) {
int strLen;
if (cs == null || (strLen = cs.length()) == 0) {
return true;
}
for (int i = 0; i < strLen; i++) {
if (!Character.isWhitespace(cs.charAt(i))) {
return false;
}
}
return true;
}
/**
* Checks if a CharSequence is not empty (""), not null and not whitespace only.
*
* Whitespace is defined by {@link Character#isWhitespace(char)}.
*
*
* StringUtils.isNotBlank(null) = false
* StringUtils.isNotBlank("") = false
* StringUtils.isNotBlank(" ") = false
* StringUtils.isNotBlank("bob") = true
* StringUtils.isNotBlank(" bob ") = true
*
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if the CharSequence is
* not empty and not null and not whitespace only
* @since 2.0
* @since 3.0 Changed signature from isNotBlank(String) to isNotBlank(CharSequence)
*/
public static boolean isNotBlank(final CharSequence cs) {
return !isBlank(cs);
}
// SubStringAfter/SubStringBefore
//-----------------------------------------------------------------------
/**
* Gets the substring before the first occurrence of a separator.
* The separator is not returned.
*
* A {@code null} string input will return {@code null}.
* An empty ("") string input will return the empty string.
* A {@code null} separator will return the input string.
*
* If nothing is found, the string input is returned.
*
*
* StringUtils.substringBefore(null, *) = null
* StringUtils.substringBefore("", *) = ""
* StringUtils.substringBefore("abc", "a") = ""
* StringUtils.substringBefore("abcba", "b") = "a"
* StringUtils.substringBefore("abc", "c") = "ab"
* StringUtils.substringBefore("abc", "d") = "abc"
* StringUtils.substringBefore("abc", "") = ""
* StringUtils.substringBefore("abc", null) = "abc"
*
*
* @param str the String to get a substring from, may be null
* @param separator the String to search for, may be null
* @return the substring before the first occurrence of the separator,
* {@code null} if null String input
* @since 2.0
*/
public static String substringBefore(final String str, final String separator) {
if (isEmpty(str) || separator == null) {
return str;
}
if (separator.isEmpty()) {
return EMPTY;
}
final int pos = str.indexOf(separator);
if (pos == INDEX_NOT_FOUND) {
return str;
}
return str.substring(0, pos);
}
/**
* Gets the substring after the first occurrence of a separator.
* The separator is not returned.
*
* A {@code null} string input will return {@code null}.
* An empty ("") string input will return the empty string.
* A {@code null} separator will return the empty string if the
* input string is not {@code null}.
*
* If nothing is found, the empty string is returned.
*
*
* StringUtils.substringAfter(null, *) = null
* StringUtils.substringAfter("", *) = ""
* StringUtils.substringAfter(*, null) = ""
* StringUtils.substringAfter("abc", "a") = "bc"
* StringUtils.substringAfter("abcba", "b") = "cba"
* StringUtils.substringAfter("abc", "c") = ""
* StringUtils.substringAfter("abc", "d") = ""
* StringUtils.substringAfter("abc", "") = "abc"
*
*
* @param str the String to get a substring from, may be null
* @param separator the String to search for, may be null
* @return the substring after the first occurrence of the separator,
* {@code null} if null String input
* @since 2.0
*/
public static String substringAfter(final String str, final String separator) {
if (isEmpty(str)) {
return str;
}
if (separator == null) {
return EMPTY;
}
final int pos = str.indexOf(separator);
if (pos == INDEX_NOT_FOUND) {
return EMPTY;
}
return str.substring(pos + separator.length());
}
/**
* Gets the substring after the last occurrence of a separator.
* The separator is not returned.
*
* A {@code null} string input will return {@code null}.
* An empty ("") string input will return the empty string.
* An empty or {@code null} separator will return the empty string if
* the input string is not {@code null}.
*
* If nothing is found, the empty string is returned.
*
*
* StringUtils.substringAfterLast(null, *) = null
* StringUtils.substringAfterLast("", *) = ""
* StringUtils.substringAfterLast(*, "") = ""
* StringUtils.substringAfterLast(*, null) = ""
* StringUtils.substringAfterLast("abc", "a") = "bc"
* StringUtils.substringAfterLast("abcba", "b") = "a"
* StringUtils.substringAfterLast("abc", "c") = ""
* StringUtils.substringAfterLast("a", "a") = ""
* StringUtils.substringAfterLast("a", "z") = ""
*
*
* @param str the String to get a substring from, may be null
* @param separator the String to search for, may be null
* @return the substring after the last occurrence of the separator,
* {@code null} if null String input
* @since 2.0
*/
public static String substringAfterLast(final String str, final String separator) {
if (isEmpty(str)) {
return str;
}
if (isEmpty(separator)) {
return EMPTY;
}
final int pos = str.lastIndexOf(separator);
if (pos == INDEX_NOT_FOUND || pos == str.length() - separator.length()) {
return EMPTY;
}
return str.substring(pos + separator.length());
}
/**
* Gets the substring before the last occurrence of a separator.
* The separator is not returned.
*
* A {@code null} string input will return {@code null}.
* An empty ("") string input will return the empty string.
* An empty or {@code null} separator will return the input string.
*
* If nothing is found, the string input is returned.
*
*
* StringUtils.substringBeforeLast(null, *) = null
* StringUtils.substringBeforeLast("", *) = ""
* StringUtils.substringBeforeLast("abcba", "b") = "abc"
* StringUtils.substringBeforeLast("abc", "c") = "ab"
* StringUtils.substringBeforeLast("a", "a") = ""
* StringUtils.substringBeforeLast("a", "z") = "a"
* StringUtils.substringBeforeLast("a", null) = "a"
* StringUtils.substringBeforeLast("a", "") = "a"
*
*
* @param str the String to get a substring from, may be null
* @param separator the String to search for, may be null
* @return the substring before the last occurrence of the separator,
* {@code null} if null String input
* @since 2.0
*/
public static String substringBeforeLast(final String str, final String separator) {
if (isEmpty(str) || isEmpty(separator)) {
return str;
}
final int pos = str.lastIndexOf(separator);
if (pos == INDEX_NOT_FOUND) {
return str;
}
return str.substring(0, pos);
}
// Count matches
//-----------------------------------------------------------------------
/**
* Counts how many times the substring appears in the larger string.
*
* A {@code null} or empty ("") String input returns {@code 0}.
*
*
* StringUtils.countMatches(null, *) = 0
* StringUtils.countMatches("", *) = 0
* StringUtils.countMatches("abba", null) = 0
* StringUtils.countMatches("abba", "") = 0
* StringUtils.countMatches("abba", "a") = 2
* StringUtils.countMatches("abba", "ab") = 1
* StringUtils.countMatches("abba", "xxx") = 0
*
*
* @param str the CharSequence to check, may be null
* @param sub the substring to count, may be null
* @return the number of occurrences, 0 if either CharSequence is {@code null}
* @since 3.0 Changed signature from countMatches(String, String) to countMatches(CharSequence, CharSequence)
*/
public static int countMatches(final CharSequence str, final CharSequence sub) {
if (isEmpty(str) || isEmpty(sub)) {
return 0;
}
int count = 0;
int idx = 0;
while ((idx = CharSequenceUtils.indexOf(str, sub, idx)) != INDEX_NOT_FOUND) {
count++;
idx += sub.length();
}
return count;
}
/**
* Counts how many times the char appears in the given string.
*
* A {@code null} or empty ("") String input returns {@code 0}.
*
*
* StringUtils.countMatches(null, *) = 0
* StringUtils.countMatches("", *) = 0
* StringUtils.countMatches("abba", 0) = 0
* StringUtils.countMatches("abba", 'a') = 2
* StringUtils.countMatches("abba", 'b') = 2
* StringUtils.countMatches("abba", 'x') = 0
*
*
* @param str the CharSequence to check, may be null
* @param ch the char to count
* @return the number of occurrences, 0 if the CharSequence is {@code null}
* @since 3.4
*/
public static int countMatches(final CharSequence str, final char ch) {
if (isEmpty(str)) {
return 0;
}
int count = 0;
// We could also call str.toCharArray() for faster look ups but that would generate more garbage.
for (int i = 0; i < str.length(); i++) {
if (ch == str.charAt(i)) {
count++;
}
}
return count;
}
/**
* Removes control characters (char <= 32) from both
* ends of this String returning an empty String ("") if the String
* is empty ("") after the trim or if it is {@code null}.
*
*
The String is trimmed using {@link String#trim()}.
* Trim removes start and end characters <= 32.
*
*
* StringUtils.trimToEmpty(null) = ""
* StringUtils.trimToEmpty("") = ""
* StringUtils.trimToEmpty(" ") = ""
* StringUtils.trimToEmpty("abc") = "abc"
* StringUtils.trimToEmpty(" abc ") = "abc"
*
*
* @param str the String to be trimmed, may be null
* @return the trimmed String, or an empty String if {@code null} input
* @since 2.0
*/
public static String trimToEmpty(final String str) {
return str == null ? EMPTY : str.trim();
}
/**
* Removes a substring only if it is at the end of a source string,
* otherwise returns the source string.
*
* A {@code null} source string will return {@code null}.
* An empty ("") source string will return the empty string.
* A {@code null} search string will return the source string.
*
*
* StringUtils.removeEnd(null, *) = null
* StringUtils.removeEnd("", *) = ""
* StringUtils.removeEnd(*, null) = *
* StringUtils.removeEnd("www.domain.com", ".com.") = "www.domain.com"
* StringUtils.removeEnd("www.domain.com", ".com") = "www.domain"
* StringUtils.removeEnd("www.domain.com", "domain") = "www.domain.com"
* StringUtils.removeEnd("abc", "") = "abc"
*
*
* @param str the source String to search, may be null
* @param remove the String to search for and remove, may be null
* @return the substring with the string removed if found,
* {@code null} if null String input
* @since 2.1
*/
public static String removeEnd(final String str, final String remove) {
if (isEmpty(str) || isEmpty(remove)) {
return str;
}
if (str.endsWith(remove)) {
return str.substring(0, str.length() - remove.length());
}
return str;
}
/**
* Strips any of a set of characters from the end of a String.
*
* A {@code null} input String returns {@code null}.
* An empty string ("") input returns the empty string.
*
* If the stripChars String is {@code null}, whitespace is
* stripped as defined by {@link Character#isWhitespace(char)}.
*
*
* StringUtils.stripEnd(null, *) = null
* StringUtils.stripEnd("", *) = ""
* StringUtils.stripEnd("abc", "") = "abc"
* StringUtils.stripEnd("abc", null) = "abc"
* StringUtils.stripEnd(" abc", null) = " abc"
* StringUtils.stripEnd("abc ", null) = "abc"
* StringUtils.stripEnd(" abc ", null) = " abc"
* StringUtils.stripEnd(" abcyx", "xyz") = " abc"
* StringUtils.stripEnd("120.00", ".0") = "12"
*
*
* @param str the String to remove characters from, may be null
* @param stripChars the set of characters to remove, null treated as whitespace
* @return the stripped String, {@code null} if null String input
*/
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);
}
/**
* Case insensitive removal of a substring if it is at the beginning of a source string,
* otherwise returns the source string.
*
* A {@code null} source string will return {@code null}.
* An empty ("") source string will return the empty string.
* A {@code null} search string will return the source string.
*
*
* StringUtils.removeStartIgnoreCase(null, *) = null
* StringUtils.removeStartIgnoreCase("", *) = ""
* StringUtils.removeStartIgnoreCase(*, null) = *
* StringUtils.removeStartIgnoreCase("www.domain.com", "www.") = "domain.com"
* StringUtils.removeStartIgnoreCase("www.domain.com", "WWW.") = "domain.com"
* StringUtils.removeStartIgnoreCase("domain.com", "www.") = "domain.com"
* StringUtils.removeStartIgnoreCase("www.domain.com", "domain") = "www.domain.com"
* StringUtils.removeStartIgnoreCase("abc", "") = "abc"
*
*
* @param str the source String to search, may be null
* @param remove the String to search for (case insensitive) and remove, may be null
* @return the substring with the string removed if found,
* {@code null} if null String input
* @since 2.4
*/
public static String removeStartIgnoreCase(final String str, final String remove) {
if (isEmpty(str) || isEmpty(remove)) {
return str;
}
if (startsWithIgnoreCase(str, remove)) {
return str.substring(remove.length());
}
return str;
}
/**
* Case insensitive check if a CharSequence starts with a specified prefix.
*
* {@code null}s are handled without exceptions. Two {@code null}
* references are considered to be equal. The comparison is case insensitive.
*
*
* StringUtils.startsWithIgnoreCase(null, null) = true
* StringUtils.startsWithIgnoreCase(null, "abc") = false
* StringUtils.startsWithIgnoreCase("abcdef", null) = false
* StringUtils.startsWithIgnoreCase("abcdef", "abc") = true
* StringUtils.startsWithIgnoreCase("ABCDEF", "abc") = true
*
*
* @see java.lang.String#startsWith(String)
* @param str the CharSequence to check, may be null
* @param prefix the prefix to find, may be null
* @return {@code true} if the CharSequence starts with the prefix, case insensitive, or
* both {@code null}
* @since 2.4
* @since 3.0 Changed signature from startsWithIgnoreCase(String, String) to startsWithIgnoreCase(CharSequence, CharSequence)
*/
public static boolean startsWithIgnoreCase(final CharSequence str, final CharSequence prefix) {
return startsWith(str, prefix, true);
}
/**
* Check if a CharSequence starts with a specified prefix (optionally case insensitive).
*
* @see java.lang.String#startsWith(String)
* @param str the CharSequence to check, may be null
* @param prefix the prefix to find, may be null
* @param ignoreCase indicates whether the compare should ignore case
* (case insensitive) or not.
* @return {@code true} if the CharSequence starts with the prefix or
* both {@code null}
*/
private static boolean startsWith(final CharSequence str, final CharSequence prefix, final boolean ignoreCase) {
if (str == null || prefix == null) {
return str == prefix;
}
if (prefix.length() > str.length()) {
return false;
}
return CharSequenceUtils.regionMatches(str, ignoreCase, 0, prefix, 0, prefix.length());
}
/**
* Checks if CharSequence contains a search CharSequence irrespective of case,
* handling {@code null}. Case-insensitivity is defined as by
* {@link String#equalsIgnoreCase(String)}.
*
*
A {@code null} CharSequence will return {@code false}.
*
*
* StringUtils.containsIgnoreCase(null, *) = false
* StringUtils.containsIgnoreCase(*, null) = false
* StringUtils.containsIgnoreCase("", "") = true
* StringUtils.containsIgnoreCase("abc", "") = true
* StringUtils.containsIgnoreCase("abc", "a") = true
* StringUtils.containsIgnoreCase("abc", "z") = false
* StringUtils.containsIgnoreCase("abc", "A") = true
* StringUtils.containsIgnoreCase("abc", "Z") = false
*
*
* @param str the CharSequence to check, may be null
* @param searchStr the CharSequence to find, may be null
* @return true if the CharSequence contains the search CharSequence irrespective of
* case or false if not or {@code null} string input
* @since 3.0 Changed signature from containsIgnoreCase(String, String) to containsIgnoreCase(CharSequence, CharSequence)
*/
public static boolean containsIgnoreCase(final CharSequence str, final CharSequence searchStr) {
if (str == null || searchStr == null) {
return false;
}
final int len = searchStr.length();
final int max = str.length() - len;
for (int i = 0; i <= max; i++) {
if (CharSequenceUtils.regionMatches(str, true, i, searchStr, 0, len)) {
return true;
}
}
return false;
}
/**
* Removes a substring only if it is at the beginning of a source string,
* otherwise returns the source string.
*
* A {@code null} source string will return {@code null}.
* An empty ("") source string will return the empty string.
* A {@code null} search string will return the source string.
*
*
* StringUtils.removeStart(null, *) = null
* StringUtils.removeStart("", *) = ""
* StringUtils.removeStart(*, null) = *
* StringUtils.removeStart("www.domain.com", "www.") = "domain.com"
* StringUtils.removeStart("domain.com", "www.") = "domain.com"
* StringUtils.removeStart("www.domain.com", "domain") = "www.domain.com"
* StringUtils.removeStart("abc", "") = "abc"
*
*
* @param str the source String to search, may be null
* @param remove the String to search for and remove, may be null
* @return the substring with the string removed if found,
* {@code null} if null String input
* @since 2.1
*/
public static String removeStart(final String str, final String remove) {
if (isEmpty(str) || isEmpty(remove)) {
return str;
}
if (str.startsWith(remove)){
return str.substring(remove.length());
}
return str;
}
/**
* Performs the logic for the {@code split} and
* {@code splitPreserveAllTokens} methods that return a maximum array
* length.
*
* @param str the String to parse, may be {@code null}
* @param separatorChars the separate character
* @param max the maximum number of elements to include in the
* array. A zero or negative value implies no limit.
* @param preserveAllTokens if {@code true}, adjacent separators are
* treated as empty token separators; if {@code false}, adjacent
* separators are treated as one separator.
* @return an array of parsed Strings, {@code null} if null String input
*/
private static String[] splitWorker(final String str, final String separatorChars, final int max, final boolean preserveAllTokens) {
// Performance tuned for 2.0 (JDK1.4)
// Direct code is quicker than StringTokenizer.
// Also, StringTokenizer uses isSpace() not isWhitespace()
if (str == null) {
return null;
}
final int len = str.length();
if (len == 0) {
return new String[0];
}
final List list = new ArrayList<>();
int sizePlus1 = 1;
int i = 0, start = 0;
boolean match = false;
boolean lastMatch = false;
if (separatorChars == null) {
// Null separator means use whitespace
while (i < len) {
if (Character.isWhitespace(str.charAt(i))) {
if (match || preserveAllTokens) {
lastMatch = true;
if (sizePlus1++ == max) {
i = len;
lastMatch = false;
}
list.add(str.substring(start, i));
match = false;
}
start = ++i;
continue;
}
lastMatch = false;
match = true;
i++;
}
} else if (separatorChars.length() == 1) {
// Optimise 1 character case
final char sep = separatorChars.charAt(0);
while (i < len) {
if (str.charAt(i) == sep) {
if (match || preserveAllTokens) {
lastMatch = true;
if (sizePlus1++ == max) {
i = len;
lastMatch = false;
}
list.add(str.substring(start, i));
match = false;
}
start = ++i;
continue;
}
lastMatch = false;
match = true;
i++;
}
} else {
// standard case
while (i < len) {
if (separatorChars.indexOf(str.charAt(i)) >= 0) {
if (match || preserveAllTokens) {
lastMatch = true;
if (sizePlus1++ == max) {
i = len;
lastMatch = false;
}
list.add(str.substring(start, i));
match = false;
}
start = ++i;
continue;
}
lastMatch = false;
match = true;
i++;
}
}
if (match || (preserveAllTokens && lastMatch)) {
list.add(str.substring(start, i));
}
return list.toArray(new String[list.size()]);
}
/**
* Performs the logic for the {@code split} and
* {@code splitPreserveAllTokens} methods that do not return a
* maximum array length.
*
* @param str the String to parse, may be {@code null}
* @param separatorChar the separate character
* @param preserveAllTokens if {@code true}, adjacent separators are
* treated as empty token separators; if {@code false}, adjacent
* separators are treated as one separator.
* @return an array of parsed Strings, {@code null} if null String input
*/
private static String[] splitWorker(final String str, final char separatorChar, final boolean preserveAllTokens) {
// Performance tuned for 2.0 (JDK1.4)
if (str == null) {
return null;
}
final int len = str.length();
if (len == 0) {
return new String[0];
}
final List list = new ArrayList<>();
int i = 0, start = 0;
boolean match = false;
boolean lastMatch = false;
while (i < len) {
if (str.charAt(i) == separatorChar) {
if (match || preserveAllTokens) {
list.add(str.substring(start, i));
match = false;
lastMatch = true;
}
start = ++i;
continue;
}
lastMatch = false;
match = true;
i++;
}
if (match || (preserveAllTokens && lastMatch)) {
list.add(str.substring(start, i));
}
return list.toArray(new String[list.size()]);
}
/**
* Splits the provided text into an array, separators specified.
* This is an alternative to using StringTokenizer.
*
* The separator is not included in the returned String array.
* Adjacent separators are treated as one separator.
* For more control over the split use the StrTokenizer class.
*
* A {@code null} input String returns {@code null}.
* A {@code null} separatorChars splits on whitespace.
*
*
* StringUtils.split(null, *) = null
* StringUtils.split("", *) = []
* StringUtils.split("abc def", null) = ["abc", "def"]
* StringUtils.split("abc def", " ") = ["abc", "def"]
* StringUtils.split("abc def", " ") = ["abc", "def"]
* StringUtils.split("ab:cd:ef", ":") = ["ab", "cd", "ef"]
*
*
* @param str the String to parse, may be null
* @param separatorChars the characters used as the delimiters,
* {@code null} splits on whitespace
* @return an array of parsed Strings, {@code null} if null String input
*/
public static String[] split(final String str, final String separatorChars) {
return splitWorker(str, separatorChars, -1, false);
}
/**
* Splits the provided text into an array, separator specified.
* This is an alternative to using StringTokenizer.
*
* The separator is not included in the returned String array.
* Adjacent separators are treated as one separator.
* For more control over the split use the StrTokenizer class.
*
* A {@code null} input String returns {@code null}.
*
*
* StringUtils.split(null, *) = null
* StringUtils.split("", *) = []
* StringUtils.split("a.b.c", '.') = ["a", "b", "c"]
* StringUtils.split("a..b.c", '.') = ["a", "b", "c"]
* StringUtils.split("a:b:c", '.') = ["a:b:c"]
* StringUtils.split("a b c", ' ') = ["a", "b", "c"]
*
*
* @param str the String to parse, may be null
* @param separatorChar the character used as the delimiter
* @return an array of parsed Strings, {@code null} if null String input
* @since 2.0
*/
public static String[] split(final String str, final char separatorChar) {
return splitWorker(str, separatorChar, false);
}
/**
* Joins the elements of the provided array into a single String
* containing the provided list of elements.
*
* No delimiter is added before or after the list.
* 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"], ';') = "a;b;c"
* StringUtils.join(["a", "b", "c"], null) = "abc"
* StringUtils.join([null, "", "a"], ';') = ";;a"
*
*
* @param array the array of values to join together, may be null
* @param separator the separator character to use
* @return the joined String, {@code null} if null array input
* @since 2.0
*/
public static String join(final Object[] array, final char separator) {
if (array == null) {
return null;
}
return join(array, separator, 0, array.length);
}
/**
* Joins the elements of the provided array into a single String
* containing the provided list of elements.
*
* No delimiter is added before or after the list.
* 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"], ';') = "a;b;c"
* StringUtils.join(["a", "b", "c"], null) = "abc"
* StringUtils.join([null, "", "a"], ';') = ";;a"
*
*
* @param array the array of values to join together, may be null
* @param separator the separator character to use
* @param startIndex the first index to start joining from. It is
* an error to pass in an end index past the end of the array
* @param endIndex the index to stop joining from (exclusive). It is
* an error to pass in an end index past the end of the array
* @return the joined String, {@code null} if null array input
* @since 2.0
*/
public static String join(final Object[] array, final char separator, final int startIndex, final int endIndex) {
if (array == null) {
return null;
}
final int noOfItems = endIndex - startIndex;
if (noOfItems <= 0) {
return EMPTY;
}
final StringBuilder buf = newStringBuilder(noOfItems);
for (int i = startIndex; i < endIndex; i++) {
if (i > startIndex) {
buf.append(separator);
}
if (array[i] != null) {
buf.append(array[i]);
}
}
return buf.toString();
}
/**
* Joins the elements of the provided {@code Iterator} into
* a single String containing the provided elements.
*
* No delimiter is added before or after the list. Null objects or empty
* strings within the iteration are represented by empty strings.
*
* See the examples here: {@link #join(Object[],char)}.
*
* @param iterator the {@code Iterator} of values to join together, may be null
* @param separator the separator character to use
* @return the joined String, {@code null} if null iterator input
* @since 2.0
*/
public static String join(final Iterator iterator, final char separator) {
// handle null, zero and one elements before building a buffer
if (iterator == null) {
return null;
}
if (!iterator.hasNext()) {
return EMPTY;
}
final Object first = iterator.next();
if (!iterator.hasNext()) {
return Objects.toString(first, EMPTY);
}
// two or more elements
final StringBuilder buf = new StringBuilder(STRING_BUILDER_SIZE); // Java default is 16, probably too small
if (first != null) {
buf.append(first);
}
while (iterator.hasNext()) {
buf.append(separator);
final Object obj = iterator.next();
if (obj != null) {
buf.append(obj);
}
}
return buf.toString();
}
/**
* Joins the elements of the provided {@code Iterable} into
* a single String containing the provided elements.
*
* No delimiter is added before or after the list. Null objects or empty
* strings within the iteration are represented by empty strings.
*
* See the examples here: {@link #join(Object[],char)}.
*
* @param iterable the {@code Iterable} providing the values to join together, may be null
* @param separator the separator character to use
* @return the joined String, {@code null} if null iterator input
* @since 2.3
*/
public static String join(final Iterable iterable, final char separator) {
if (iterable == null) {
return null;
}
return join(iterable.iterator(), separator);
}
private static StringBuilder newStringBuilder(final int noOfItems) {
return new StringBuilder(noOfItems * 16);
}
/**
* Convert an InputStream into a String.
*
* Highest performing conversion per: https://stackoverflow.com/a/35446009
*
* @param inputStream The input stream to be converted.
* @param charset The decoding charset to use.
* @return The string value of the input stream, null otherwise.
* @throws IOException If there are any issues in reading from the stream.
*/
public static String inputStreamToString(InputStream inputStream, Charset charset) throws IOException {
if (inputStream != null && inputStream.available() != -1) {
ByteArrayOutputStream result = new ByteArrayOutputStream();
byte[] buffer = new byte[1024];
int length;
while ((length = inputStream.read(buffer)) != -1) {
result.write(buffer, 0, length);
}
if (charset != null) {
return result.toString(charset.name());
}
return result.toString(StandardCharsets.UTF_8.name());
}
return null;
}
public static boolean isEmail(String userIdEmail) {
Matcher matcher = pattern.matcher(userIdEmail);
return matcher.matches();
}
/**
* Check whether the given {@code String} contains actual text.
* More specifically, this method returns {@code true} if the
* {@code String} is not {@code null}, its length is greater than 0,
* and it contains at least one non-whitespace character.
* @param str the {@code String} to check (may be {@code null})
* @return {@code true} if the {@code String} is not {@code null}, its
* length is greater than 0, and it does not contain whitespace only
* @see Character#isWhitespace
*/
public static boolean hasText(String str) {
return (str != null && !str.isEmpty() && containsText(str));
}
private static boolean containsText(CharSequence str) {
int strLen = str.length();
for (int i = 0; i < strLen; i++) {
if (!Character.isWhitespace(str.charAt(i))) {
return true;
}
}
return false;
}
/**
* Check that the given {@code String} is neither {@code null} nor of length 0.
*
Note: this method returns {@code true} for a {@code String} that
* purely consists of whitespace.
* @param str the {@code String} to check (may be {@code null})
* @return {@code true} if the {@code String} is not {@code null} and has length
* @see #hasText(String)
*/
public static boolean hasLength(String str) {
return (str != null && !str.isEmpty());
}
/**
* Tokenize the given {@code String} into a {@code String} array via a
* {@link StringTokenizer}.
*
Trims tokens and omits empty tokens.
*
The given {@code delimiters} string can consist of any number of
* delimiter characters. Each of those characters can be used to separate
* tokens. A delimiter is always a single character; for multi-character
* delimiters, consider using delimitedListToStringArray.
* @param str the {@code String} to tokenize (potentially {@code null} or empty)
* @param delimiters the delimiter characters, assembled as a {@code String}
* (each of the characters is individually considered as a delimiter)
* @return an array of the tokens
* @see java.util.StringTokenizer
* @see String#trim()
*/
public static String[] tokenizeToStringArray(String str, String delimiters) {
return tokenizeToStringArray(str, delimiters, true, true);
}
/**
* Tokenize the given {@code String} into a {@code String} array via a
* {@link StringTokenizer}.
*
The given {@code delimiters} string can consist of any number of
* delimiter characters. Each of those characters can be used to separate
* tokens. A delimiter is always a single character; for multi-character
* delimiters, consider using delimitedListToStringArray.
* @param str the {@code String} to tokenize (potentially {@code null} or empty)
* @param delimiters the delimiter characters, assembled as a {@code String}
* (each of the characters is individually considered as a delimiter)
* @param trimTokens trim the tokens via {@link String#trim()}
* @param ignoreEmptyTokens omit empty tokens from the result array
* (only applies to tokens that are empty after trimming; StringTokenizer
* will not consider subsequent delimiters as token in the first place).
* @return an array of the tokens
* @see java.util.StringTokenizer
* @see String#trim()
*/
public static String[] tokenizeToStringArray(
String str, String delimiters, boolean trimTokens, boolean ignoreEmptyTokens) {
if (str == null) {
return EMPTY_STRING_ARRAY;
}
StringTokenizer st = new StringTokenizer(str, delimiters);
List tokens = new ArrayList<>();
while (st.hasMoreTokens()) {
String token = st.nextToken();
if (trimTokens) {
token = token.trim();
}
if (!ignoreEmptyTokens || token.length() > 0) {
tokens.add(token);
}
}
return toStringArray(tokens);
}
/**
* Copy the given {@link Collection} into a {@code String} array.
* The {@code Collection} must contain {@code String} elements only.
* @param collection the {@code Collection} to copy
* (potentially {@code null} or empty)
* @return the resulting {@code String} array
*/
public static String[] toStringArray(Collection collection) {
return (!CollectionUtils.isEmpty(collection) ? collection.toArray(EMPTY_STRING_ARRAY) : EMPTY_STRING_ARRAY);
}
/**
* Convert a {@link Collection} to a delimited {@code String} (e.g. CSV).
* Useful for {@code toString()} implementations.
* @param coll the {@code Collection} to convert (potentially {@code null} or empty)
* @param delim the delimiter to use (typically a ",")
* @param prefix the {@code String} to start each element with
* @param suffix the {@code String} to end each element with
* @return the delimited {@code String}
*/
public static String collectionToDelimitedString(
Collection coll, String delim, String prefix, String suffix) {
if (CollectionUtils.isEmpty(coll)) {
return "";
}
StringBuilder sb = new StringBuilder();
Iterator it = coll.iterator();
while (it.hasNext()) {
sb.append(prefix).append(it.next()).append(suffix);
if (it.hasNext()) {
sb.append(delim);
}
}
return sb.toString();
}
/**
* Convert a {@code Collection} into a delimited {@code String} (e.g. CSV).
*
Useful for {@code toString()} implementations.
* @param coll the {@code Collection} to convert (potentially {@code null} or empty)
* @param delim the delimiter to use (typically a ",")
* @return the delimited {@code String}
*/
public static String collectionToDelimitedString(Collection coll, String delim) {
return collectionToDelimitedString(coll, delim, "", "");
}
/**
* Convert a {@code Collection} into a delimited {@code String} (e.g., CSV).
*
Useful for {@code toString()} implementations.
* @param coll the {@code Collection} to convert (potentially {@code null} or empty)
* @return the delimited {@code String}
*/
public static String collectionToCommaDelimitedString(Collection coll) {
return collectionToDelimitedString(coll, ",");
}
/**
* Check if a string is numeric.
* @param str input
* @return boolean true is numeric
*/
public static boolean isNumeric(String str) {
if (str == null) {
return false;
}
int sz = str.length();
for (int i = 0; i < sz; i++) {
if (Character.isDigit(str.charAt(i)) == false) {
return false;
}
}
return true;
}
/**
* Check if a string is a JWT token.
* @param str input
* @return boolean true is jwt
*/
public static boolean isJwtToken(String str) {
if (str == null) {
return false;
} else {
// not null
if(str.indexOf("eyJ") >= 0 && str.indexOf(".") > 0) {
return true;
} else {
return false;
}
}
}
/**
* Mask the first half of a string with asterisks for sensitive data before logging.
* @param str input
* @return masked string
*/
public static String maskHalfString(String str) {
if (str == null) {
return null;
} else {
// not null
int halfLength = str.length() / 2;
String masked = "*".repeat(halfLength) + str.substring(halfLength);
return masked;
}
}
/**
* Match a URL against an OpenAPI endpoint pattern with curly brackets path parameters
* @param requestPath the incoming request path
* @param endpointPattern the OpenAPI endpoint pattern with curly brackets path parameters
* @return boolean true matched
*/
public static boolean matchPathToPattern(String requestPath, String endpointPattern) {
String[] pathPatternParts = endpointPattern.split("/");
String[] pathParts = requestPath.split("/");
boolean isMatch = true;
for (int i = 0; i < pathPatternParts.length; i++) {
String patternPart = pathPatternParts[i];
String urlPart = pathParts[i];
if (patternPart.startsWith("{") && patternPart.endsWith("}")) {
continue; // Wildcard found, move to the next part
}
if (!patternPart.equals(urlPart)) {
isMatch = false; // Part does not match, URLs do not match
break;
}
}
return isMatch;
}
}