cl.core.util.Strings Maven / Gradle / Ivy
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package cl.core.util;
import java.util.function.IntPredicate;
/**
* String utilities.
*/
public final class Strings {
private Strings() {}
/**
* Capitalize the first character of the string. The rest of the string will hold it's original case.
* Return null if the input is null.
*/
public static String capitalize(CharSequence s) {
return capitalize(s, false);
}
/**
* Capitalize the first character of the string. Optionally, bring the rest
* of the string to lower case.
*
* @param s input string
* @param forceLowercase if true bring the rest of the string to lower case,
* leave original case otherwise
*/
public static String capitalize(CharSequence s, boolean forceLowercase) {
if (s == null) return null;
if (s.length() == 0) return "";
return new StringBuilder()
.append(Character.toUpperCase(s.charAt(0)))
.append(forceLowercase ?
s.subSequence(1, s.length()).toString().toLowerCase() :
s.subSequence(1, s.length()))
.toString();
}
/**
* Convert a string in so called "snake" case (f.e. this_is_my_snake_case_string)
* into a string in Camel case.
*
* This method merely removes underscores and capitalizes characters after them.
* It will not make any changes to other characters' case, nor it will remove
* spaces.
*/
public static String snakeToCamel(CharSequence s) {
return delimitedToCamel(s, ch -> ch == '_', false);
}
/**
* Convert a string in Camel case into a string in snake case.
*/
public static String camelToSnake(CharSequence s) {
return camelToDelimited(s, '_');
}
/**
* Convert a dash-separated string (f.e. this-is-my-dash-separated-string)
* into a string in Camel case.
*
*
This method merely removes dashes and capitalizes characters after them.
* It will not make any changes to other characters' case, nor it will remove
* spaces.
*/
public static String dashedToCamel(CharSequence s) {
return delimitedToCamel(s, ch -> ch == '-', false);
}
/**
* Convert a string in Camel case into a string where words are separated by dashes.
*/
public static String camelToDashed(CharSequence s) {
return camelToDelimited(s, '-');
}
/**
* Convert a dot-separated string (f.e. this.is.my.dot.separated.string)
* into a string in Camel case.
*
*
This method merely removes dots and capitalizes characters after them.
* It will not make any changes to other characters' case, nor it will remove
* spaces.
*/
public static String dottedToCamel(CharSequence s) {
return delimitedToCamel(s, ch -> ch == '.', false);
}
/**
* Convert a string in Camel case into a string where words are separated by dots.
*/
public static String camelToDotted(CharSequence s) {
return camelToDelimited(s, '.');
}
/**
* Convert a whitespace-separated string into a string in Camel case.
* The characters which follow white space characters will be capitalized,
* while the rest of the characters will be brought to lower case.
*/
public static String spacedToCamel(CharSequence s) {
return delimitedToCamel(s, ch -> Character.isWhitespace(ch), true);
}
/**
* Convert a string in Camel case into a string where words are separated by spaces.
*/
public static String camelToSpaced(CharSequence s) {
return camelToDelimited(s, ' ');
}
/**
* Convert a Pascal case string into a Camel case string. It returns
* the same string as input but with the first character in lower case.
*/
public static String pascalToCamel(CharSequence s) {
if (s == null) return null;
if (s.length() == 0) return "";
return new StringBuilder()
.append(Character.toLowerCase(s.charAt(0)))
.append(s.subSequence(1, s.length()))
.toString();
}
private static String delimitedToCamel(
CharSequence s, IntPredicate delimiterTest, boolean forceLowercase) {
if (s == null) return null;
if (s.length() == 0) return "";
StringBuilder sb = new StringBuilder();
boolean lastWasDelimiter = false;
for (char ch : s.toString().toCharArray()) {
if (delimiterTest.test(ch)) {
lastWasDelimiter = true;
} else {
if (lastWasDelimiter) {
sb.append(Character.toUpperCase(ch));
lastWasDelimiter = false;
} else {
sb.append(forceLowercase ? Character.toLowerCase(ch) : ch);
}
}
}
return sb.toString();
}
private static String camelToDelimited(CharSequence s, char delimiter) {
if (s == null) return null;
if (s.length() == 0) return "";
StringBuilder sb = new StringBuilder();
for (char ch : s.toString().toCharArray()) {
if (Character.isUpperCase(ch)) {
sb.append(delimiter);
sb.append(Character.toLowerCase(ch));
} else {
sb.append(ch);
}
}
return sb.toString();
}
}