/*
* 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.ketayao.fensy.util;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
public class StringUtils {
/**
* 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 = "";
public static boolean equals(CharSequence cs1, CharSequence cs2) {
return cs1 == null ? cs2 == null : cs1.equals(cs2);
}
/**
* Tests if this string ends with the specified suffix.
*
* @param src String to test
* @param subS suffix
*
* @return <code>true</code> if the character sequence represented by the argument is
* a suffix of the character sequence represented by this object;
* <code>false</code> otherwise.
*/
public static boolean endsWithIgnoreCase(String src, String subS) {
if (src == null || subS == null) {
return src == subS;
}
String sub = subS.toLowerCase();
int sublen = sub.length();
int j = 0;
int i = src.length() - sublen;
if (i < 0) {
return false;
}
while (j < sublen) {
char source = Character.toLowerCase(src.charAt(i));
if (sub.charAt(j) != source) {
return false;
}
j++;
i++;
}
return true;
}
/**
* <p>Checks if a CharSequence is whitespace, empty ("") or null.</p>
*
* <pre>
* StringUtils.isBlank(null) = true
* StringUtils.isBlank("") = true
* StringUtils.isBlank(" ") = true
* StringUtils.isBlank("bob") = false
* StringUtils.isBlank(" bob ") = false
* </pre>
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if the CharSequence is null, empty or whitespace
* @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)) == false) {
return false;
}
}
return true;
}
public static String[] split(final String str) {
return split(str, null, -1);
}
/**
* <p>Splits the provided text into an array, separators specified.
* This is an alternative to using StringTokenizer.</p>
*
* <p>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.</p>
*
* <p>A {@code null} input String returns {@code null}.
* A {@code null} separatorChars splits on whitespace.</p>
*
* <pre>
* 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"]
* </pre>
*
* @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);
}
public static String[] split(final String str, final String separatorChars, final int max) {
return splitWorker(str, separatorChars, max, false);
}
/**
* <p>Splits the provided text into an array, separator specified.
* This is an alternative to using StringTokenizer.</p>
*
* <p>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.</p>
*
* <p>A {@code null} input String returns {@code null}.</p>
*
* <pre>
* 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"]
* </pre>
*
* @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);
}
/**
* 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<String> list = new ArrayList<String>();
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()]);
}
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<String> list = new ArrayList<String>();
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()]);
}
/**
* <p>Checks if a CharSequence is not empty (""), not null and not whitespace only.</p>
*
* <pre>
* StringUtils.isNotBlank(null) = false
* StringUtils.isNotBlank("") = false
* StringUtils.isNotBlank(" ") = false
* StringUtils.isNotBlank("bob") = true
* StringUtils.isNotBlank(" bob ") = true
* </pre>
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if the CharSequence is
* not empty and not null and not whitespace
* @since 2.0
* @since 3.0 Changed signature from isNotBlank(String) to isNotBlank(CharSequence)
*/
public static boolean isNotBlank(final CharSequence cs) {
return !isBlank(cs);
}
public static boolean isEmpty(final CharSequence cs) {
return cs == null || cs.length() == 0;
}
/**
* <p>Gets the substring after the first occurrence of a separator.
* The separator is not returned.</p>
*
* <p>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}.</p>
*
* <p>If nothing is found, the empty string is returned.</p>
*
* <pre>
* 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"
* </pre>
*
* @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());
}
/**
* <p>Gets the substring before the last occurrence of a separator.
* The separator is not returned.</p>
*
* <p>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.</p>
*
* <p>If nothing is found, the string input is returned.</p>
*
* <pre>
* 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"
* </pre>
*
* @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);
}
/**
* <p>Gets the substring before the first occurrence of a separator.
* The separator is not returned.</p>
*
* <p>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.</p>
*
* <p>If nothing is found, the string input is returned.</p>
*
* <pre>
* 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"
* </pre>
*
* @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);
}
/**
* Finds first occurrence of a substring in the given source but within limited range [start, end).
* It is fastest possible code, but still original <code>String.indexOf(String, int)</code>
* is much faster (since it uses char[] value directly) and should be used when no range is needed.
*
* @param src source string for examination
* @param sub substring to find
* @param startIndex starting index
* @param endIndex ending index
* @return index of founded substring or -1 if substring not found
*/
public static int indexOf(String src, String sub, int startIndex, int endIndex) {
if (startIndex < 0) {
startIndex = 0;
}
int srclen = src.length();
if (endIndex > srclen) {
endIndex = srclen;
}
int sublen = sub.length();
if (sublen == 0) {
return startIndex > srclen ? srclen : startIndex;
}
int total = endIndex - sublen + 1;
char c = sub.charAt(0);
mainloop: for (int i = startIndex; i < total; i++) {
if (src.charAt(i) != c) {
continue;
}
int j = 1;
int k = i + 1;
while (j < sublen) {
if (sub.charAt(j) != src.charAt(k)) {
continue mainloop;
}
j++;
k++;
}
return i;
}
return -1;
}
/**
* Finds the first occurrence of a character in the given source but within limited range (start, end].
*/
public static int indexOf(String src, char c, int startIndex, int endIndex) {
if (startIndex < 0) {
startIndex = 0;
}
int srclen = src.length();
if (endIndex > srclen) {
endIndex = srclen;
}
for (int i = startIndex; i < endIndex; i++) {
if (src.charAt(i) == c) {
return i;
}
}
return -1;
}
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());
}
/**
* <p>Checks if the CharSequence contains only Unicode digits.
* A decimal point is not a Unicode digit and returns false.</p>
*
* <p>{@code null} will return {@code false}.
* An empty CharSequence (length()=0) will return {@code false}.</p>
*
* <p>Note that the method does not allow for a leading sign, either positive or negative.
* Also, if a String passes the numeric test, it may still generate a NumberFormatException
* when parsed by Integer.parseInt or Long.parseLong, e.g. if the value is outside the range
* for int or long respectively.</p>
*
* <pre>
* StringUtils.isNumeric(null) = false
* StringUtils.isNumeric("") = false
* StringUtils.isNumeric(" ") = false
* StringUtils.isNumeric("123") = true
* StringUtils.isNumeric("\u0967\u0968\u0969") = true
* StringUtils.isNumeric("12 3") = false
* StringUtils.isNumeric("ab2c") = false
* StringUtils.isNumeric("12-3") = false
* StringUtils.isNumeric("12.3") = false
* StringUtils.isNumeric("-123") = false
* StringUtils.isNumeric("+123") = false
* </pre>
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if only contains digits, and is non-null
* @since 3.0 Changed signature from isNumeric(String) to isNumeric(CharSequence)
* @since 3.0 Changed "" to return false and not true
*/
public static boolean isNumeric(final CharSequence cs) {
if (isEmpty(cs)) {
return false;
}
final int sz = cs.length();
for (int i = 0; i < sz; i++) {
if (Character.isDigit(cs.charAt(i)) == false) {
return false;
}
}
return true;
}
/**
* <p>Checks if the CharSequence contains only lowercase characters.</p>
*
* <p>{@code null} will return {@code false}.
* An empty CharSequence (length()=0) will return {@code false}.</p>
*
* <pre>
* StringUtils.isAllLowerCase(null) = false
* StringUtils.isAllLowerCase("") = false
* StringUtils.isAllLowerCase(" ") = false
* StringUtils.isAllLowerCase("abc") = true
* StringUtils.isAllLowerCase("abC") = false
* StringUtils.isAllLowerCase("ab c") = false
* StringUtils.isAllLowerCase("ab1c") = false
* StringUtils.isAllLowerCase("ab/c") = false
* </pre>
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if only contains lowercase characters, and is non-null
* @since 2.5
* @since 3.0 Changed signature from isAllLowerCase(String) to isAllLowerCase(CharSequence)
*/
public static boolean isAllLowerCase(final CharSequence cs) {
if (cs == null || isEmpty(cs)) {
return false;
}
final int sz = cs.length();
for (int i = 0; i < sz; i++) {
if (Character.isLowerCase(cs.charAt(i)) == false) {
return false;
}
}
return true;
}
/**
* <p>Checks if the CharSequence contains only uppercase characters.</p>
*
* <p>{@code null} will return {@code false}.
* An empty String (length()=0) will return {@code false}.</p>
*
* <pre>
* StringUtils.isAllUpperCase(null) = false
* StringUtils.isAllUpperCase("") = false
* StringUtils.isAllUpperCase(" ") = false
* StringUtils.isAllUpperCase("ABC") = true
* StringUtils.isAllUpperCase("aBC") = false
* StringUtils.isAllUpperCase("A C") = false
* StringUtils.isAllUpperCase("A1C") = false
* StringUtils.isAllUpperCase("A/C") = false
* </pre>
*
* @param cs the CharSequence to check, may be null
* @return {@code true} if only contains uppercase characters, and is non-null
* @since 2.5
* @since 3.0 Changed signature from isAllUpperCase(String) to isAllUpperCase(CharSequence)
*/
public static boolean isAllUpperCase(final CharSequence cs) {
if (cs == null || isEmpty(cs)) {
return false;
}
final int sz = cs.length();
for (int i = 0; i < sz; i++) {
if (Character.isUpperCase(cs.charAt(i)) == false) {
return false;
}
}
return true;
}
/**
* <p>Joins the elements of the provided {@code Iterator} into
* a single String containing the provided elements.</p>
*
* <p>No delimiter is added before or after the list.
* A {@code null} separator is the same as an empty String ("").</p>
*
* <p>See the examples here: {@link #join(Object[],String)}. </p>
*
* @param iterator the {@code Iterator} of values to join together, may be null
* @param separator the separator character to use, null treated as ""
* @return the joined String, {@code null} if null iterator input
*/
public static String join(final Iterator<?> iterator, final String 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 first == null ? "" : first.toString();
}
// two or more elements
final StringBuilder buf = new StringBuilder(256); // Java default is 16, probably too small
if (first != null) {
buf.append(first);
}
while (iterator.hasNext()) {
if (separator != null) {
buf.append(separator);
}
final Object obj = iterator.next();
if (obj != null) {
buf.append(obj);
}
}
return buf.toString();
}
/**
* <p>Joins the elements of the provided {@code Iterator} into
* a single String containing the provided elements.</p>
*
* <p>No delimiter is added before or after the list. Null objects or empty
* strings within the iteration are represented by empty strings.</p>
*
* <p>See the examples here: {@link #join(Object[],char)}. </p>
*
* @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 first == null ? "" : first.toString();
}
// two or more elements
final StringBuilder buf = new StringBuilder(256); // 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();
}
/**
*
* @param kvs
* @param separator
* @return
*/
public static String join(List<String> kvs, char separator) {
if (kvs == null) {
return null;
}
return join(kvs.iterator(), separator);
}
}