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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 io.microsphere.util;
import java.util.StringTokenizer;
import static io.microsphere.util.ArrayUtils.asArray;
import static java.lang.Character.isWhitespace;
import static java.lang.String.valueOf;
/**
* The utilities class for {@link String}
*
* @author Mercy
* @since 1.0.0
*/
public abstract class StringUtils {
public final static String EMPTY = "";
public static final String[] EMPTY_STRING_ARRAY = ArrayUtils.EMPTY_STRING_ARRAY;
public static int length(String value) {
return value == null ? 0 : value.length();
}
public static boolean isEmpty(String value) {
return length(value) == 0;
}
public static boolean isNotEmpty(String value) {
return length(value) > 0;
}
public static boolean isBlank(String value) {
int length = length(value);
if (length < 1) {
return true;
}
for (int i = 0; i < length; i++) {
if (!isWhitespace(value.charAt(i))) {
return false;
}
}
return true;
}
public static boolean isNotBlank(String value) {
return !isBlank(value);
}
public static String[] split(String value, char delimiter) {
return split(value, valueOf(delimiter));
}
public static String[] split(String value, String delimiter) {
if (isEmpty(value)) {
return EMPTY_STRING_ARRAY;
}
StringTokenizer stringTokenizer = new StringTokenizer(value, delimiter);
return (String[]) asArray(stringTokenizer, String.class);
}
public static boolean contains(String value, CharSequence part) {
if (value != null && part != null) {
return value.contains(part);
}
return false;
}
public static boolean startsWith(String value, String part) {
if (value != null && part != null) {
return value.startsWith(part);
}
return false;
}
public static boolean endsWith(String value, String part) {
if (value != null && part != null) {
return value.endsWith(part);
}
return false;
}
// Copy following stuffs from Apache Commons Lang StringUtils
/**
* Represents a failed index search.
*/
public static final int INDEX_NOT_FOUND = -1;
/**
* 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"
*
*
* @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"
*
*
* @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 (isEmpty(text) || isEmpty(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));
StringBuffer buf = new StringBuffer(text.length() + increase);
while (end != INDEX_NOT_FOUND) {
buf.append(text, start, end).append(replacement);
start = end + replLength;
if (--max == 0) {
break;
}
end = text.indexOf(searchString, start);
}
buf.append(text.substring(start));
return buf.toString();
}
/**
* Gets the String that is nested in between two instances of the
* same String.
*
* A null input String returns null.
* A null tag returns null.
*
*
* StringUtils.substringBetween(null, *) = null
* StringUtils.substringBetween("", "") = ""
* StringUtils.substringBetween("", "tag") = null
* StringUtils.substringBetween("tagabctag", null) = null
* StringUtils.substringBetween("tagabctag", "") = ""
* StringUtils.substringBetween("tagabctag", "tag") = "abc"
*
*
* @param str the String containing the substring, may be null
* @param tag the String before and after the substring, may be null
* @return the substring, null if no match
*/
public static String substringBetween(String str, String tag) {
return substringBetween(str, tag, tag);
}
/**
* Gets the String that is nested in between two Strings.
* Only the first match is returned.
*
* A null input String returns null.
* A null open/close returns null (no match).
* An empty ("") open and close returns an empty string.
*
*
* StringUtils.substringBetween("wx[b]yz", "[", "]") = "b"
* StringUtils.substringBetween(null, *, *) = null
* StringUtils.substringBetween(*, null, *) = null
* StringUtils.substringBetween(*, *, null) = null
* StringUtils.substringBetween("", "", "") = ""
* StringUtils.substringBetween("", "", "]") = null
* StringUtils.substringBetween("", "[", "]") = null
* StringUtils.substringBetween("yabcz", "", "") = ""
* StringUtils.substringBetween("yabcz", "y", "z") = "abc"
* StringUtils.substringBetween("yabczyabcz", "y", "z") = "abc"
*
*
* @param str the String containing the substring, may be null
* @param open the String before the substring, may be null
* @param close the String after the substring, may be null
* @return the substring, null if no match
*/
public static String substringBetween(String str, String open, String close) {
if (str == null || open == null || close == null) {
return null;
}
int start = str.indexOf(open);
if (start != INDEX_NOT_FOUND) {
int end = str.indexOf(close, start + open.length());
if (end != INDEX_NOT_FOUND) {
return str.substring(start + open.length(), end);
}
}
return null;
}
/**
* Gets the substring before the first occurrence of a separator.
* The separator is not returned.
*
* A null string input will return null.
* An empty ("") string input will return the empty string.
* A 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,
* null if null String input
*/
public static String substringBefore(String str, String separator) {
if (isEmpty(str) || separator == null) {
return str;
}
if (separator.length() == 0) {
return EMPTY;
}
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 null string input will return null.
* An empty ("") string input will return the empty string.
* A null separator will return the empty string if the
* input string is not 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,
* null if null String input
*/
public static String substringAfter(String str, String separator) {
if (isEmpty(str)) {
return str;
}
if (separator == null) {
return EMPTY;
}
int pos = str.indexOf(separator);
if (pos == INDEX_NOT_FOUND) {
return EMPTY;
}
return str.substring(pos + separator.length());
}
/**
* Gets the substring before the last occurrence of a separator.
* The separator is not returned.
*
* A null string input will return null.
* An empty ("") string input will return the empty string.
* An empty or 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,
* null if null String input
*/
public static String substringBeforeLast(String str, String separator) {
if (isEmpty(str) || isEmpty(separator)) {
return str;
}
int pos = str.lastIndexOf(separator);
if (pos == INDEX_NOT_FOUND) {
return str;
}
return str.substring(0, pos);
}
/**
* Gets the substring after the last occurrence of a separator.
* The separator is not returned.
*
* A null string input will return null.
* An empty ("") string input will return the empty string.
* An empty or null separator will return the empty string if
* the input string is not 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,
* null if null String input
*/
public static String substringAfterLast(String str, String separator) {
if (isEmpty(str)) {
return str;
}
if (isEmpty(separator)) {
return EMPTY;
}
int pos = str.lastIndexOf(separator);
if (pos == INDEX_NOT_FOUND || pos == (str.length() - separator.length())) {
return EMPTY;
}
return str.substring(pos + separator.length());
}
}