org.owasp.html.Strings Maven / Gradle / Ivy
// Copyright (c) 2011, Mike Samuel
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
// Redistributions of source code must retain the above copyright
// notice, this list of conditions and the following disclaimer.
// Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
// Neither the name of the OWASP nor the names of its contributors may
// be used to endorse or promote products derived from this software
// without specific prior written permission.
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
// FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
// COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
// ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
package org.owasp.html;
/**
* Locale independent versions of String case-insensitive operations.
*
* The normal case insensitive operators {@link String#toLowerCase}
* and {@link String#equalsIgnoreCase} depend upon the current locale.
* They will fold the letters "i" and "I" differently if the locale is
* Turkish than if it is English.
*
* These operations ignore all case folding for non-Roman letters, and are
* independent of the current locale.
* Lower-casing is exactly equivalent to {@code tr/A-Z/a-z/}, upper-casing to
* {@code tr/a-z/A-Z/}, and case insensitive comparison is equivalent to
* lower-casing both then comparing by code-unit.
*
* Because of this simpler case folding, it is the case that for all Strings s
*
* Strings.toUpperCase(s).equals(Strings.toUpperCase(Strings.toLowerCase(s)))
* .
*
* @author Mike Samuel ([email protected])
*/
final class Strings {
/*
public static boolean equalsIgnoreCase(
@Nullable String a, @Nullable String b) {
if (a == null) { return b == null; }
if (b == null) { return false; }
int length = a.length();
if (b.length() != length) { return false; }
for (int i = length; --i >= 0;) {
char c = a.charAt(i), d = b.charAt(i);
if (c != d) {
if (c <= 'z' && c >= 'A') {
if (c <= 'Z') { c |= 0x20; }
if (d <= 'Z' && d >= 'A') { d |= 0x20; }
if (c == d) { continue; }
}
return false;
}
}
return true;
}
*/
public static boolean regionMatchesIgnoreCase(
CharSequence a, int aoffset, CharSequence b, int boffset, int n) {
if (aoffset + n > a.length() || boffset + n > b.length()) { return false; }
for (int i = n; --i >= 0;) {
char c = a.charAt(aoffset + i), d = b.charAt(boffset + i);
if (c != d) {
if (c <= 'z' && c >= 'A') {
if (c <= 'Z') { c |= 0x20; }
if (d <= 'Z' && d >= 'A') { d |= 0x20; }
if (c == d) { continue; }
}
return false;
}
}
return true;
}
/** True iff {@code s.equals(String.toLowerCase(s))}. */
/*
public static boolean isLowerCase(CharSequence s) {
for (int i = s.length(); --i >= 0;) {
char c = s.charAt(i);
if (c <= 'Z' && c >= 'A') {
return false;
}
}
return true;
}
*/
private static final char[] LCASE_CHARS = new char['Z' + 1];
private static final char[] UCASE_CHARS = new char['z' + 1];
static {
for (int i = 0; i < 'A'; ++i) { LCASE_CHARS[i] = (char) i; }
for (int i = 'A'; i <= 'Z'; ++i) { LCASE_CHARS[i] = (char) (i | 0x20); }
for (int i = 0; i < 'a'; ++i) { UCASE_CHARS[i] = (char) i; }
for (int i = 'a'; i <= 'z'; ++i) { UCASE_CHARS[i] = (char) (i & ~0x20); }
}
public static String toLowerCase(String s) {
for (int i = s.length(); --i >= 0;) {
char c = s.charAt(i);
if (c <= 'Z' && c >= 'A') {
char[] chars = s.toCharArray();
chars[i] = LCASE_CHARS[c];
while (--i >= 0) {
c = chars[i];
if (c <= 'Z') {
chars[i] = LCASE_CHARS[c];
}
}
return String.valueOf(chars);
}
}
return s;
}
/*
public static String toUpperCase(String s) {
for (int i = s.length(); --i >= 0;) {
char c = s.charAt(i);
if (c <= 'z' && c >= 'a') {
char[] chars = s.toCharArray();
chars[i] = UCASE_CHARS[c];
while (--i >= 0) {
c = chars[i];
if (c <= 'z') {
chars[i] = UCASE_CHARS[c];
}
}
return String.valueOf(chars);
}
}
return s;
}
*/
private static final long HTML_SPACE_CHAR_BITMASK =
(1L << ' ')
| (1L << '\t')
| (1L << '\n')
| (1L << '\u000c')
| (1L << '\r');
static boolean isHtmlSpace(int ch) {
return ch <= 0x20 && (HTML_SPACE_CHAR_BITMASK & (1L << ch)) != 0;
}
static boolean containsHtmlSpace(String s) {
for (int i = 0, n = s.length(); i < n; ++i) {
if (isHtmlSpace(s.charAt(i))) { return true; }
}
return false;
}
static String stripHtmlSpaces(String s) {
int i = 0, n = s.length();
for (; n > i; --n) {
if (!isHtmlSpace(s.charAt(n - 1))) {
break;
}
}
for (; i < n; ++i) {
if (!isHtmlSpace(s.charAt(i))) {
break;
}
}
if (i == 0 && n == s.length()) {
return s;
}
return s.substring(i, n);
}
/**
* Parses a valid floating point number per the HTML5 spec.
* https://html.spec.whatwg.org/multipage/common-microsyntaxes.html#valid-floating-point-number
*
* @param start the start of the floating point number on s.
* @return the end of the floating point number if valid or -1 if not.
*/
static int skipValidFloatingPointNumber(String value, int start) {
// A string is a valid floating-point number if it consists of:
int i = start;
final int n = value.length();
if (i >= n) {
return -1;
}
// 1. Optionally, a U+002D HYPHEN-MINUS character (-).
if (value.charAt(i) == '-') {
++i;
}
// 2. One or both of the following, in the given order:
boolean hasMantissa = false;
// 1. A series of one or more ASCII digits.
while (i < n) {
char ch = value.charAt(i);
if ('0' <= ch && ch <= '9') {
++i;
hasMantissa = true;
} else {
break;
}
}
// 2. Both of the following, in the given order:
// 1. A single U+002E FULL STOP character (.).
// 2. A series of one or more ASCII digits.
if (i < n && value.charAt(i) == '.') {
++i;
// Even if there's an integer, you need digits after the decimal point.
hasMantissa = false;
while (i < n) {
char ch = value.charAt(i);
if ('0' <= ch && ch <= '9') {
++i;
hasMantissa = true;
} else {
break;
}
}
}
if (!hasMantissa) {
return -1;
}
// 3. Optionally:
// 1. Either a U+0065 LATIN SMALL LETTER E character (e)
// or a U+0045 LATIN CAPITAL LETTER E character (E).
if (i < n && (value.charAt(i) | 32) == 'e') {
++i;
// 2. Optionally, a U+002D HYPHEN-MINUS character (-) or
// U+002B PLUS SIGN character (+).
if (i < n) {
char ch = value.charAt(i);
if (ch == '+' || ch == '-') {
++i;
}
}
// 3. A series of one or more ASCII digits.
boolean hasExponent = false;
while (i < n) {
char ch = value.charAt(i);
if ('0' <= ch && ch <= '9') {
++i;
hasExponent = true;
} else {
break;
}
}
if (!hasExponent) {
return -1;
}
}
return i;
}
private Strings() { /* uninstantiable */ }
}