com.ctc.wstx.util.StringUtil Maven / Gradle / Ivy
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package com.ctc.wstx.util;
import java.util.Collection;
import java.util.Iterator;
public final class StringUtil
{
final static char CHAR_SPACE = ' '; // 0x0020
private final static char INT_SPACE = 0x0020;
static String sLF = null;
public static String getLF()
{
String lf = sLF;
if (lf == null) {
try {
lf = System.getProperty("line.separator");
sLF = (lf == null) ? "\n" : lf;
} catch (Throwable t) {
// Doh.... whatever; most likely SecurityException
sLF = lf = "\n";
}
}
return lf;
}
public static void appendLF(StringBuilder sb) {
sb.append(getLF());
}
public static String concatEntries(Collection coll, String sep, String lastSep) {
if (lastSep == null) {
lastSep = sep;
}
int len = coll.size();
StringBuilder sb = new StringBuilder(16 + (len << 3));
Iterator it = coll.iterator();
int i = 0;
while (it.hasNext()) {
if (i == 0) {
;
} else if (i == (len - 1)) {
sb.append(lastSep);
} else {
sb.append(sep);
}
++i;
sb.append(it.next());
}
return sb.toString();
}
/**
* Method that will check character array passed, and remove all
* "extra" spaces (leading and trailing space), and normalize
* other white space (more than one consequtive space character
* replaced with a single space).
*
* NOTE: we only remove explicit space characters (char code 0x0020);
* the reason being that other white space must have come from
* non-normalizable sources, ie. via entity expansion, and is thus
* not to be normalized
*
* @param buf Buffer that contains the String to check
* @param origStart Offset of the first character of the text to check
* in the buffer
* @param origEnd Offset of the character following the last character
* of the text (as per usual Java API convention)
*
* @return Normalized String, if any white space was removed or
* normalized; null if no changes were necessary.
*/
public static String normalizeSpaces(char[] buf, int origStart, int origEnd)
{
--origEnd;
int start = origStart;
int end = origEnd;
// First let's trim start...
while (start <= end && buf[start] == CHAR_SPACE) {
++start;
}
// Was it all empty?
if (start > end) {
return "";
}
/* Nope, need to trim from the end then (note: it's known that char
* at index 'start' is not a space, at this point)
*/
while (end > start && buf[end] == CHAR_SPACE) {
--end;
}
/* Ok, may have changes or not: now need to normalize
* intermediate duplicate spaces. We also now that the
* first and last characters can not be spaces.
*/
int i = start+1;
while (i < end) {
if (buf[i] == CHAR_SPACE) {
if (buf[i+1] == CHAR_SPACE) {
break;
}
// Nah; no hole for these 2 chars!
i += 2;
} else {
++i;
}
}
// Hit the end?
if (i >= end) {
// Any changes?
if (start == origStart && end == origEnd) {
return null; // none
}
return new String(buf, start, (end-start)+1);
}
/* Nope, got a hole, need to constuct the damn thing. Shouldn't
* happen too often... so let's just use StringBuilder()
*/
StringBuilder sb = new StringBuilder(end-start); // can't be longer
sb.append(buf, start, i-start); // won't add the starting space
while (i <= end) {
char c = buf[i++];
if (c == CHAR_SPACE) {
sb.append(CHAR_SPACE);
// Need to skip dups
while (true) {
c = buf[i++];
if (c != CHAR_SPACE) {
sb.append(c);
break;
}
}
} else {
sb.append(c);
}
}
return sb.toString();
}
public static boolean isAllWhitespace(String str)
{
for (int i = 0, len = str.length(); i < len; ++i) {
if (str.charAt(i) > CHAR_SPACE) {
return false;
}
}
return true;
}
public static boolean isAllWhitespace(char[] ch, int start, int len)
{
len += start;
for (; start < len; ++start) {
if (ch[start] > CHAR_SPACE) {
return false;
}
}
return true;
}
/**
* Internal constant used to denote END-OF-STRING
*/
private final static int EOS = 0x10000;
/**
* Method that implements a loose String compairon for encoding
* Strings. It will work like {@link String#equalsIgnoreCase},
* except that it will also ignore all hyphen, underscore and
* space characters.
*/
public static boolean equalEncodings(String str1, String str2)
{
final int len1 = str1.length();
final int len2 = str2.length();
// Need to loop completely over both Strings
for (int i1 = 0, i2 = 0; i1 < len1 || i2 < len2; ) {
int c1 = (i1 >= len1) ? EOS : str1.charAt(i1++);
int c2 = (i2 >= len2) ? EOS : str2.charAt(i2++);
// Can first do a quick comparison (usually they are equal)
if (c1 == c2) {
continue;
}
// if not equal, maybe there are WS/hyphen/underscores to skip
while (c1 <= INT_SPACE || c1 == '_' || c1 == '-') {
c1 = (i1 >= len1) ? EOS : str1.charAt(i1++);
}
while (c2 <= INT_SPACE || c2 == '_' || c2 == '-') {
c2 = (i2 >= len2) ? EOS : str2.charAt(i2++);
}
// Ok, how about case differences, then?
if (c1 != c2) {
// If one is EOF, can't match (one is substring of the other)
if (c1 == EOS || c2 == EOS) {
return false;
}
if (c1 < 127) { // ascii is easy...
if (c1 <= 'Z' && c1 >= 'A') {
c1 = c1 + ('a' - 'A');
}
} else {
c1 = Character.toLowerCase((char)c1);
}
if (c2 < 127) { // ascii is easy...
if (c2 <= 'Z' && c2 >= 'A') {
c2 = c2 + ('a' - 'A');
}
} else {
c2 = Character.toLowerCase((char)c2);
}
if (c1 != c2) {
return false;
}
}
}
// If we got this far, we are ok as long as we got through it all
return true;
}
public static boolean encodingStartsWith(String enc, String prefix)
{
int len1 = enc.length();
int len2 = prefix.length();
int i1 = 0, i2 = 0;
// Need to loop completely over both Strings
while (i1 < len1 || i2 < len2) {
int c1 = (i1 >= len1) ? EOS : enc.charAt(i1++);
int c2 = (i2 >= len2) ? EOS : prefix.charAt(i2++);
// Can first do a quick comparison (usually they are equal)
if (c1 == c2) {
continue;
}
// if not equal, maybe there are WS/hyphen/underscores to skip
while (c1 <= CHAR_SPACE || c1 == '_' || c1 == '-') {
c1 = (i1 >= len1) ? EOS : enc.charAt(i1++);
}
while (c2 <= CHAR_SPACE || c2 == '_' || c2 == '-') {
c2 = (i2 >= len2) ? EOS : prefix.charAt(i2++);
}
// Ok, how about case differences, then?
if (c1 != c2) {
if (c2 == EOS) { // Prefix done, good!
return true;
}
if (c1 == EOS) { // Encoding done, not good
return false;
}
if (Character.toLowerCase((char)c1) != Character.toLowerCase((char)c2)) {
return false;
}
}
}
// Ok, prefix was exactly the same as encoding... that's fine
return true;
}
/**
* Method that will remove all non-alphanumeric characters, and optionally
* upper-case included letters, from the given String.
*/
public static String trimEncoding(String str, boolean upperCase)
{
int i = 0;
int len = str.length();
// Let's first check if String is fine as is:
for (; i < len; ++i) {
char c = str.charAt(i);
if (c <= CHAR_SPACE || !Character.isLetterOrDigit(c)) {
break;
}
}
if (i == len) {
return str;
}
// Nope: have to trim it
StringBuilder sb = new StringBuilder();
if (i > 0) {
sb.append(str.substring(0, i));
}
for (; i < len; ++i) {
char c = str.charAt(i);
if (c > CHAR_SPACE && Character.isLetterOrDigit(c)) {
if (upperCase) {
c = Character.toUpperCase(c);
}
sb.append(c);
}
}
return sb.toString();
}
public static boolean matches(String str, char[] cbuf, int offset, int len)
{
if (str.length() != len) {
return false;
}
for (int i = 0; i < len; ++i) {
if (str.charAt(i) != cbuf[offset+i]) {
return false;
}
}
return true;
}
/**
*
* Note that it is assumed that any "weird" white space
* (xml 1.1 LSEP and NEL) have been replaced by canonical
* alternatives (linefeed for element content, regular space
* for attributes)
*/
@SuppressWarnings("cast")
public final static boolean isSpace(char c)
{
return ((int) c) <= 0x0020;
}
}