com.jdroid.java.utils.StringUtils Maven / Gradle / Ivy
package com.jdroid.java.utils;
import com.jdroid.java.collections.Lists;
import com.jdroid.java.collections.Sets;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
/**
* This class contains functions for managing Strings
*/
public abstract class StringUtils {
public final static String EMPTY = "";
public final static String ELLIPSIS = "...";
public final static String COMMA = ",";
public final static String SPACE = " ";
public final static String DASH = "-";
public final static String SLASH = "/";
public final static String DOT = ".";
public final static String NEW_LINE = "\n";
public final static String UNDERSCORE = "_";
public final static String BANG = "!";
public final static String PIPE = "|";
private final static String PLACEHOLDER_PATTERN = "\\$\\{(.*?)\\}";
private final static String ALPHANUMERIC_PATTERN = "([^\\w\\s])*";
public static String getNotEmptyString(String text) {
return StringUtils.isEmpty(text) ? null : text;
}
public static Boolean equal(String text1, String text2) {
return defaultString(text1).equals(defaultString(text2));
}
public static Boolean isEmpty(String text) {
return text != null ? text.length() == 0 : true;
}
public static Boolean isNotEmpty(String text) {
return !isEmpty(text);
}
/**
*
* Checks if a String is whitespace, empty ("") or null.
*
*
*
* StringUtils.isBlank(null) = true
* StringUtils.isBlank("") = true
* StringUtils.isBlank(" ") = true
* StringUtils.isBlank("bob") = false
* StringUtils.isBlank(" bob ") = false
*
*
* @param str the String to check, may be null
* @return true if the String is null, empty or whitespace
*/
public static boolean isBlank(String str) {
int strLen;
if ((str == null) || ((strLen = str.length()) == 0)) {
return true;
}
for (int i = 0; i < strLen; i++) {
if (!Character.isWhitespace(str.charAt(i))) {
return false;
}
}
return true;
}
/**
*
* Checks if a String is not empty (""), not null and not whitespace only.
*
*
*
* StringUtils.isNotBlank(null) = false
* StringUtils.isNotBlank("") = false
* StringUtils.isNotBlank(" ") = false
* StringUtils.isNotBlank("bob") = true
* StringUtils.isNotBlank(" bob ") = true
*
*
* @param str the String to check, may be null
* @return true if the String is not empty and not null and not whitespace
*/
public static boolean isNotBlank(String str) {
return !StringUtils.isBlank(str);
}
/**
*
* Returns either the passed in String, or if the String is null, an empty String ("").
*
*
*
* StringUtils.defaultString(null) = ""
* StringUtils.defaultString("") = ""
* StringUtils.defaultString("bat") = "bat"
*
*
* @param str the String to check, may be null
* @return the passed in String, or the empty String if it was null
*/
public static String defaultString(String str) {
return defaultString(str, EMPTY);
}
public static String defaultString(String str, String defaultString) {
return str == null ? defaultString : str;
}
public static String capitalize(String text) {
if (isEmpty(text) || (text.length() == 1)) {
return text.toUpperCase();
}
return text.substring(0, 1).toUpperCase() + text.substring(1).toLowerCase();
}
/**
*
* Capitalizes all the whitespace separated words in a String. Only the first letter of each word is changed. To
* convert the rest of each word to lowercase at the same time, use {@link #capitalize(String)}.
*
*
*
* Whitespace is defined by {@link Character#isWhitespace(char)}. A null input String returns
* null. Capitalization uses the unicode title case, normally equivalent to upper case.
*
*
*
* WordUtils.capitalize(null) = null
* WordUtils.capitalize("") = ""
* WordUtils.capitalize("i am FINE") = "I Am FINE"
*
*
* @param str the String to capitalize, may be null
* @return capitalized String, null if null String input
*/
public static String capitalizeWords(String str) {
return capitalizeWords(str, null);
}
/**
*
* Capitalizes all the delimiter separated words in a String. Only the first letter of each word is changed.
*
*
*
* The delimiters represent a set of characters understood to separate words. The first string character and the
* first non-delimiter character after a delimiter will be capitalized.
*
*
*
* A null input String returns null. Capitalization uses the unicode title case, normally
* equivalent to upper case.
*
*
*
* WordUtils.capitalize(null, *) = null
* WordUtils.capitalize("", *) = ""
* WordUtils.capitalize(*, new char[0]) = *
* WordUtils.capitalize("i am fine", null) = "I Am Fine"
* WordUtils.capitalize("i aM.fine", {'.'}) = "I aM.Fine"
*
*
* @param str the String to capitalize, may be null
* @param delimiters set of characters to determine capitalization, null means whitespace
* @return capitalized String, null if null String input
*/
public static String capitalizeWords(String str, char[] delimiters) {
int delimLen = delimiters == null ? -1 : delimiters.length;
if ((str == null) || (str.length() == 0) || (delimLen == 0)) {
return str;
}
int strLen = str.length();
StringBuilder builder = new StringBuilder(strLen);
boolean capitalizeNext = true;
for (int i = 0; i < strLen; i++) {
char ch = str.charAt(i);
if (isDelimiter(ch, delimiters)) {
builder.append(ch);
capitalizeNext = true;
} else if (capitalizeNext) {
builder.append(Character.toTitleCase(ch));
capitalizeNext = false;
} else {
builder.append(ch);
}
}
return builder.toString();
}
/**
* Is the character a delimiter.
*
* @param ch the character to check
* @param delimiters the delimiters
* @return true if it is a delimiter
*/
private static boolean isDelimiter(char ch, char[] delimiters) {
if (delimiters == null) {
return Character.isWhitespace(ch);
}
for (char delimiter : delimiters) {
if (ch == delimiter) {
return true;
}
}
return false;
}
/**
* Joins all the strings in the list in a single one separated by the separator sequence.
*
* @param objectsToJoin The objects to join.
* @param separator The separator sequence.
* @return The joined strings.
*/
public static String join(Collection objectsToJoin, String separator) {
if ((objectsToJoin != null) && !objectsToJoin.isEmpty()) {
StringBuilder builder = new StringBuilder();
for (Object object : objectsToJoin) {
builder.append(object);
builder.append(separator);
}
// Remove the last separator
return builder.substring(0, builder.length() - separator.length());
} else {
return EMPTY;
}
}
/**
* Joins all the strings in the list in a single one separated by ','.
*
* @param objectsToJoin The objects to join.
* @return The joined strings.
*/
public static String join(Collection objectsToJoin) {
return join(objectsToJoin, COMMA);
}
/**
* Truncate the text adding "..." if the truncateWords parameter is true. The ellipsis will be taken into account
* when counting the amount of characters.
*
* @param text The text to truncate
* @param maxCharacters The maximum amount of characters allowed for the returned text
* @param truncateWords True if the words should be truncated
* @return The truncated text
*/
public static String truncate(String text, Integer maxCharacters, Boolean truncateWords) {
if (isNotBlank(text)) {
StringBuilder truncatedTextBuilder = new StringBuilder();
if (text.length() > maxCharacters) {
if (truncateWords) {
// The words are truncated and the ellipsis is added when is possible
if (maxCharacters <= StringUtils.ELLIPSIS.length()) {
truncatedTextBuilder.append(text.substring(0, maxCharacters));
} else {
truncatedTextBuilder.append(text.substring(0, maxCharacters - StringUtils.ELLIPSIS.length()));
truncatedTextBuilder.append(StringUtils.ELLIPSIS);
}
} else {
// The words are not truncated and the ellipsis is not added
List words = Lists.newArrayList(text.split(SPACE));
Iterator it = words.iterator();
int usedChars = 0;
Boolean exit = false;
while (it.hasNext() && !exit) {
String word = it.next();
int increment = usedChars == 0 ? word.length() : word.length() + 1;
if ((usedChars + increment) <= maxCharacters) {
truncatedTextBuilder.append(usedChars == 0 ? word : SPACE + word);
usedChars += increment;
} else {
exit = true;
}
}
}
} else {
truncatedTextBuilder.append(text);
}
return truncatedTextBuilder.toString();
}
return text;
}
/**
* Truncate the text adding "...". The ellipsis will be taken into account when counting the amount of characters.
*
* @param text The text to truncate
* @param maxCharacters The maximum amount of characters allowed for the returned text
* @return The truncated text
*/
public static String truncate(String text, Integer maxCharacters) {
return StringUtils.truncate(text, maxCharacters, true);
}
/**
* Extract all the placeholder's names of the string
*
* @param string The whole string with placeholders
* @return A set with all the placeholder's names
*/
public static Set extractPlaceHolders(String string) {
Matcher matcher = Pattern.compile(StringUtils.PLACEHOLDER_PATTERN).matcher(string);
Set placeHolders = Sets.newHashSet();
while (matcher.find()) {
placeHolders.add(matcher.group(1));
}
return placeHolders;
}
/**
* Transform the received value removing all the not alphanumeric or spaces characters
*
* @param value The string to transform
* @return The transformed string
*/
public static String toAlphanumeric(String value) {
return Pattern.compile(StringUtils.ALPHANUMERIC_PATTERN).matcher(value).replaceAll("");
}
public static List splitToListWithCommaSeparator(String text) {
return Lists.newArrayList(splitToCollection(text, COMMA));
}
public static Collection splitToCollectionWithCommaSeparator(String text) {
return splitToCollection(text, COMMA);
}
public static Collection splitToCollection(String text, String separator) {
Collection values = Lists.newArrayList();
if (isNotEmpty(text)) {
values = Lists.newArrayList(text.split(separator));
}
return values;
}
/**
* Returns the first token of the string if that string can be split by the token, else return the unmodified input
* string
*
* @param string The string to split
* @param token The token to use as splitter
* @return The resultant string
*/
public static String getFirstToken(String string, String token) {
if ((string != null) && string.contains(token)) {
return string.split(token)[0];
}
return string;
}
/**
* Returns the first token of the string if that string can be split by a ",", else return the unmodified input
* string
*
* @param string The string to split
* @return The resultant string
*/
public static String getFirstToken(String string) {
return getFirstToken(string, COMMA);
}
/**
* This method word wrap a text to two lines if the text has multiple words and its length is greater than the
* specified minLength. To do the word wrap, the white space closest to the middle of the string is replaced by a
* "\n" character
*
* @param text A Sting, the text to word wrap to two lines.
* @param minLength The min text length to apply word wrap.
* @return The input text word wrapped to two lines or the original text.
*/
public static String wordWrapToTwoLines(String text, int minLength) {
String wordWrapText = text != null ? text.trim() : null;
if ((wordWrapText != null) && (wordWrapText.length() > minLength)) {
int middle = wordWrapText.length() / 2;
int leftSpaceIndex = wordWrapText.substring(0, middle).lastIndexOf(SPACE);
int rightSpaceIndex = wordWrapText.indexOf(SPACE, middle);
int wordWrapIndex = rightSpaceIndex;
if ((leftSpaceIndex >= 0)
&& ((rightSpaceIndex < 0) || ((middle - leftSpaceIndex) < (rightSpaceIndex - middle)))) {
wordWrapIndex = leftSpaceIndex;
}
if (wordWrapIndex >= 0) {
wordWrapText = wordWrapText.substring(0, wordWrapIndex) + "\n"
+ wordWrapText.substring(wordWrapIndex + 1);
}
}
return wordWrapText;
}
public static String replaceValues(final String template, final Map values) {
final StringBuffer sb = new StringBuffer();
final Pattern pattern = Pattern.compile("\\$\\{(.*?)\\}", Pattern.DOTALL);
final Matcher matcher = pattern.matcher(template);
while (matcher.find()) {
final String key = matcher.group(1);
final String replacement = values.get(key);
if (replacement == null) {
throw new IllegalArgumentException("Template contains unmapped key: " + key);
}
matcher.appendReplacement(sb, replacement);
}
matcher.appendTail(sb);
return sb.toString();
}
public static boolean hasOnlyCharacters(String name) {
return !isEmpty(name) && name.matches("[A-Za-z\\s]*");
}
/**
* @param charSequence a CharSequence, the charSequence to trim.
* @return a CharSequence with whitespace characters removed from the end, including non-breaking spaces ( or
* ) and line separators.
*/
public static CharSequence removeTrailingWhitespaces(CharSequence charSequence) {
CharSequence result = charSequence;
if ((charSequence != null) && (charSequence.length() > 0)) {
int lastIndex = charSequence.length() - 1;
int index = lastIndex;
while ((index >= 0) && isAnySpaceChar(charSequence.charAt(index))) {
index--;
}
if (index < lastIndex) {
result = charSequence.subSequence(0, index + 1);
}
}
return result;
}
/**
* @param character a char
* @return true if the character is a whitespace (including non-breaking spaces and line separators), false
* otherwise.
*/
private static boolean isAnySpaceChar(char character) {
return Character.isSpaceChar(character) || Character.isWhitespace(character);
}
}
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