nl.siegmann.epublib.util.StringUtil Maven / Gradle / Ivy
package nl.siegmann.epublib.util;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
/**
* Various String utility functions.
*
* Most of the functions herein are re-implementations of the ones in apache
* commons StringUtils. The reason for re-implementing this is that the
* functions are fairly simple and using my own implementation saves the
* inclusion of a 200Kb jar file.
*
* @author paul.siegmann
*
*/
public class StringUtil {
/**
* Changes a path containing '..', '.' and empty dirs into a path that
* doesn't. X/foo/../Y is changed into 'X/Y', etc. Does not handle invalid
* paths like "../".
*
* @param path
* @return the normalized path
*/
public static String collapsePathDots(String path) {
String[] stringParts = path.split("/");
List parts = new ArrayList(Arrays.asList(stringParts));
for (int i = 0; i < parts.size() - 1; i++) {
String currentDir = parts.get(i);
if (currentDir.length() == 0 || currentDir.equals(".")) {
parts.remove(i);
i--;
} else if (currentDir.equals("..")) {
parts.remove(i - 1);
parts.remove(i - 1);
i -= 2;
}
}
StringBuilder result = new StringBuilder();
if (path.startsWith("/")) {
result.append('/');
}
for (int i = 0; i < parts.size(); i++) {
result.append(parts.get(i));
if (i < (parts.size() - 1)) {
result.append('/');
}
}
return result.toString();
}
/**
* Whether the String is not null, not zero-length and does not contain of
* only whitespace.
*
* @param text
* @return Whether the String is not null, not zero-length and does not contain of
*/
public static boolean isNotBlank(String text) {
return !isBlank(text);
}
/**
* Whether the String is null, zero-length and does contain only whitespace.
*
* @return Whether the String is null, zero-length and does contain only whitespace.
*/
public static boolean isBlank(String text) {
if (isEmpty(text)) {
return true;
}
for (int i = 0; i < text.length(); i++) {
if (!Character.isWhitespace(text.charAt(i))) {
return false;
}
}
return true;
}
/**
* Whether the given string is null or zero-length.
*
* @param text the input for this method
* @return Whether the given string is null or zero-length.
*/
public static boolean isEmpty(String text) {
return (text == null) || (text.length() == 0);
}
/**
* Whether the given source string ends with the given suffix, ignoring
* case.
*
* @param source
* @param suffix
* @return Whether the given source string ends with the given suffix, ignoring case.
*/
public static boolean endsWithIgnoreCase(String source, String suffix) {
if (isEmpty(suffix)) {
return true;
}
if (isEmpty(source)) {
return false;
}
if (suffix.length() > source.length()) {
return false;
}
return source.substring(source.length() - suffix.length())
.toLowerCase().endsWith(suffix.toLowerCase());
}
/**
* If the given text is null return "", the original text otherwise.
*
* @param text
* @return If the given text is null "", the original text otherwise.
*/
public static String defaultIfNull(String text) {
return defaultIfNull(text, "");
}
/**
* If the given text is null return "", the given defaultValue otherwise.
*
* @param text
* @param defaultValue
* @return If the given text is null "", the given defaultValue otherwise.
*/
public static String defaultIfNull(String text, String defaultValue) {
if (text == null) {
return defaultValue;
}
return text;
}
/**
* Null-safe string comparator
*
* @param text1
* @param text2
* @return whether the two strings are equal
*/
public static boolean equals(String text1, String text2) {
if (text1 == null) {
return (text2 == null);
}
return text1.equals(text2);
}
/**
* Pretty toString printer.
*
* @param keyValues
* @return a string representation of the input values
*/
public static String toString(Object... keyValues) {
StringBuilder result = new StringBuilder();
result.append('[');
for (int i = 0; i < keyValues.length; i += 2) {
if (i > 0) {
result.append(", ");
}
result.append(keyValues[i]);
result.append(": ");
Object value = null;
if ((i + 1) < keyValues.length) {
value = keyValues[i + 1];
}
if (value == null) {
result.append("");
} else {
result.append('\'');
result.append(value);
result.append('\'');
}
}
result.append(']');
return result.toString();
}
public static int hashCode(String... values) {
int result = 31;
for (int i = 0; i < values.length; i++) {
result ^= String.valueOf(values[i]).hashCode();
}
return result;
}
/**
* Gives the substring of the given text before the given separator.
*
* If the text does not contain the given separator then the given text is
* returned.
*
* @param text
* @param separator
* @return the substring of the given text before the given separator.
*/
public static String substringBefore(String text, char separator) {
if (isEmpty(text)) {
return text;
}
int sepPos = text.indexOf(separator);
if (sepPos < 0) {
return text;
}
return text.substring(0, sepPos);
}
/**
* Gives the substring of the given text before the last occurrence of the
* given separator.
*
* If the text does not contain the given separator then the given text is
* returned.
*
* @param text
* @param separator
* @return the substring of the given text before the last occurrence of the given separator.
*/
public static String substringBeforeLast(String text, char separator) {
if (isEmpty(text)) {
return text;
}
int cPos = text.lastIndexOf(separator);
if (cPos < 0) {
return text;
}
return text.substring(0, cPos);
}
/**
* Gives the substring of the given text after the last occurrence of the
* given separator.
*
* If the text does not contain the given separator then "" is returned.
*
* @param text
* @param separator
* @return the substring of the given text after the last occurrence of the given separator.
*/
public static String substringAfterLast(String text, char separator) {
if (isEmpty(text)) {
return text;
}
int cPos = text.lastIndexOf(separator);
if (cPos < 0) {
return "";
}
return text.substring(cPos + 1);
}
/**
* Gives the substring of the given text after the given separator.
*
* If the text does not contain the given separator then "" is returned.
*
* @param text the input text
* @param c the separator char
* @return the substring of the given text after the given separator.
*/
public static String substringAfter(String text, char c) {
if (isEmpty(text)) {
return text;
}
int cPos = text.indexOf(c);
if (cPos < 0) {
return "";
}
return text.substring(cPos + 1);
}
}