Mainly for internal use within the framework; consider + * Jakarta's Commons Lang + * for a more comprehensive suite of String utilities. + * + *
This class delivers some simple functionality that should really
+ * be provided by the core Java String and {@link StringBuffer}
+ * classes, such as the ability to {@link #replace} all occurrences of a given
+ * substring in a target string. It also provides easy-to-use methods to convert
+ * between delimited strings, such as CSV strings, and collections and arrays.
+ *
+ * @author Rod Johnson
+ * @author Juergen Hoeller
+ * @author Keith Donald
+ * @author Rob Harrop
+ * @author Rick Evans
+ * @since 16 April 2001
+ * @see org.apache.commons.lang.StringUtils
+ */
+public abstract class StringUtils {
+
+ private static final String FOLDER_SEPARATOR = "/";
+
+ private static final String WINDOWS_FOLDER_SEPARATOR = "\\";
+
+ private static final String TOP_PATH = "..";
+
+ private static final String CURRENT_PATH = ".";
+
+ private static final char EXTENSION_SEPARATOR = '.';
+
+
+ //---------------------------------------------------------------------
+ // General convenience methods for working with Strings
+ //---------------------------------------------------------------------
+
+ /**
+ * Check that the given CharSequence is neither null nor of length 0.
+ * Note: Will return true for a CharSequence that purely consists of whitespace.
+ *
+ * StringUtils.hasLength(null) = false
+ * StringUtils.hasLength("") = false
+ * StringUtils.hasLength(" ") = true
+ * StringUtils.hasLength("Hello") = true
+ *
+ * @param str the CharSequence to check (may be null)
+ * @return true if the CharSequence is not null and has length
+ * @see #hasText(String)
+ */
+ public static boolean hasLength(CharSequence str) {
+ return (str != null && str.length() > 0);
+ }
+
+ /**
+ * Check that the given String is neither null nor of length 0.
+ * Note: Will return true for a String that purely consists of whitespace.
+ * @param str the String to check (may be null)
+ * @return true if the String is not null and has length
+ * @see #hasLength(CharSequence)
+ */
+ public static boolean hasLength(String str) {
+ return hasLength((CharSequence) str);
+ }
+
+ /**
+ * Check whether the given CharSequence has actual text.
+ * More specifically, returns true if the string not null,
+ * its length is greater than 0, and it contains at least one non-whitespace character.
+ *
+ * StringUtils.hasText(null) = false
+ * StringUtils.hasText("") = false
+ * StringUtils.hasText(" ") = false
+ * StringUtils.hasText("12345") = true
+ * StringUtils.hasText(" 12345 ") = true
+ *
+ * @param str the CharSequence to check (may be null)
+ * @return true if the CharSequence is not null,
+ * its length is greater than 0, and it does not contain whitespace only
+ * @see java.lang.Character#isWhitespace
+ */
+ public static boolean hasText(CharSequence str) {
+ if (!hasLength(str)) {
+ return false;
+ }
+ int strLen = str.length();
+ for (int i = 0; i < strLen; i++) {
+ if (!Character.isWhitespace(str.charAt(i))) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ /**
+ * Check whether the given String has actual text.
+ * More specifically, returns true if the string not null,
+ * its length is greater than 0, and it contains at least one non-whitespace character.
+ * @param str the String to check (may be null)
+ * @return true if the String is not null, its length is
+ * greater than 0, and it does not contain whitespace only
+ * @see #hasText(CharSequence)
+ */
+ public static boolean hasText(String str) {
+ return hasText((CharSequence) str);
+ }
+
+ /**
+ * Check whether the given CharSequence contains any whitespace characters.
+ * @param str the CharSequence to check (may be null)
+ * @return true if the CharSequence is not empty and
+ * contains at least 1 whitespace character
+ * @see java.lang.Character#isWhitespace
+ */
+ public static boolean containsWhitespace(CharSequence str) {
+ if (!hasLength(str)) {
+ return false;
+ }
+ int strLen = str.length();
+ for (int i = 0; i < strLen; i++) {
+ if (Character.isWhitespace(str.charAt(i))) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ /**
+ * Check whether the given String contains any whitespace characters.
+ * @param str the String to check (may be null)
+ * @return true if the String is not empty and
+ * contains at least 1 whitespace character
+ * @see #containsWhitespace(CharSequence)
+ */
+ public static boolean containsWhitespace(String str) {
+ return containsWhitespace((CharSequence) str);
+ }
+
+ /**
+ * Trim leading and trailing whitespace from the given String.
+ * @param str the String to check
+ * @return the trimmed String
+ * @see java.lang.Character#isWhitespace
+ */
+ public static String trimWhitespace(String str) {
+ if (!hasLength(str)) {
+ return str;
+ }
+ StringBuffer buf = new StringBuffer(str);
+ while (buf.length() > 0 && Character.isWhitespace(buf.charAt(0))) {
+ buf.deleteCharAt(0);
+ }
+ while (buf.length() > 0 && Character.isWhitespace(buf.charAt(buf.length() - 1))) {
+ buf.deleteCharAt(buf.length() - 1);
+ }
+ return buf.toString();
+ }
+
+ /**
+ * Trim all whitespace from the given String:
+ * leading, trailing, and inbetween characters.
+ * @param str the String to check
+ * @return the trimmed String
+ * @see java.lang.Character#isWhitespace
+ */
+ public static String trimAllWhitespace(String str) {
+ if (!hasLength(str)) {
+ return str;
+ }
+ StringBuffer buf = new StringBuffer(str);
+ int index = 0;
+ while (buf.length() > index) {
+ if (Character.isWhitespace(buf.charAt(index))) {
+ buf.deleteCharAt(index);
+ }
+ else {
+ index++;
+ }
+ }
+ return buf.toString();
+ }
+
+ /**
+ * Trim leading whitespace from the given String.
+ * @param str the String to check
+ * @return the trimmed String
+ * @see java.lang.Character#isWhitespace
+ */
+ public static String trimLeadingWhitespace(String str) {
+ if (!hasLength(str)) {
+ return str;
+ }
+ StringBuffer buf = new StringBuffer(str);
+ while (buf.length() > 0 && Character.isWhitespace(buf.charAt(0))) {
+ buf.deleteCharAt(0);
+ }
+ return buf.toString();
+ }
+
+ /**
+ * Trim trailing whitespace from the given String.
+ * @param str the String to check
+ * @return the trimmed String
+ * @see java.lang.Character#isWhitespace
+ */
+ public static String trimTrailingWhitespace(String str) {
+ if (!hasLength(str)) {
+ return str;
+ }
+ StringBuffer buf = new StringBuffer(str);
+ while (buf.length() > 0 && Character.isWhitespace(buf.charAt(buf.length() - 1))) {
+ buf.deleteCharAt(buf.length() - 1);
+ }
+ return buf.toString();
+ }
+
+ /**
+ * Trim all occurences of the supplied leading character from the given String.
+ * @param str the String to check
+ * @param leadingCharacter the leading character to be trimmed
+ * @return the trimmed String
+ */
+ public static String trimLeadingCharacter(String str, char leadingCharacter) {
+ if (!hasLength(str)) {
+ return str;
+ }
+ StringBuffer buf = new StringBuffer(str);
+ while (buf.length() > 0 && buf.charAt(0) == leadingCharacter) {
+ buf.deleteCharAt(0);
+ }
+ return buf.toString();
+ }
+
+ /**
+ * Trim all occurences of the supplied trailing character from the given String.
+ * @param str the String to check
+ * @param trailingCharacter the trailing character to be trimmed
+ * @return the trimmed String
+ */
+ public static String trimTrailingCharacter(String str, char trailingCharacter) {
+ if (!hasLength(str)) {
+ return str;
+ }
+ StringBuffer buf = new StringBuffer(str);
+ while (buf.length() > 0 && buf.charAt(buf.length() - 1) == trailingCharacter) {
+ buf.deleteCharAt(buf.length() - 1);
+ }
+ return buf.toString();
+ }
+
+
+ /**
+ * Test if the given String starts with the specified prefix,
+ * ignoring upper/lower case.
+ * @param str the String to check
+ * @param prefix the prefix to look for
+ * @see java.lang.String#startsWith
+ */
+ public static boolean startsWithIgnoreCase(String str, String prefix) {
+ if (str == null || prefix == null) {
+ return false;
+ }
+ if (str.startsWith(prefix)) {
+ return true;
+ }
+ if (str.length() < prefix.length()) {
+ return false;
+ }
+ String lcStr = str.substring(0, prefix.length()).toLowerCase();
+ String lcPrefix = prefix.toLowerCase();
+ return lcStr.equals(lcPrefix);
+ }
+
+ /**
+ * Test if the given String ends with the specified suffix,
+ * ignoring upper/lower case.
+ * @param str the String to check
+ * @param suffix the suffix to look for
+ * @see java.lang.String#endsWith
+ */
+ public static boolean endsWithIgnoreCase(String str, String suffix) {
+ if (str == null || suffix == null) {
+ return false;
+ }
+ if (str.endsWith(suffix)) {
+ return true;
+ }
+ if (str.length() < suffix.length()) {
+ return false;
+ }
+
+ String lcStr = str.substring(str.length() - suffix.length()).toLowerCase();
+ String lcSuffix = suffix.toLowerCase();
+ return lcStr.equals(lcSuffix);
+ }
+
+ /**
+ * Test whether the given string matches the given substring
+ * at the given index.
+ * @param str the original string (or StringBuffer)
+ * @param index the index in the original string to start matching against
+ * @param substring the substring to match at the given index
+ */
+ public static boolean substringMatch(CharSequence str, int index, CharSequence substring) {
+ for (int j = 0; j < substring.length(); j++) {
+ int i = index + j;
+ if (i >= str.length() || str.charAt(i) != substring.charAt(j)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ /**
+ * Count the occurrences of the substring in string s.
+ * @param str string to search in. Return 0 if this is null.
+ * @param sub string to search for. Return 0 if this is null.
+ */
+ public static int countOccurrencesOf(String str, String sub) {
+ if (str == null || sub == null || str.length() == 0 || sub.length() == 0) {
+ return 0;
+ }
+ int count = 0, pos = 0, idx = 0;
+ while ((idx = str.indexOf(sub, pos)) != -1) {
+ ++count;
+ pos = idx + sub.length();
+ }
+ return count;
+ }
+
+ /**
+ * Replace all occurences of a substring within a string with
+ * another string.
+ * @param inString String to examine
+ * @param oldPattern String to replace
+ * @param newPattern String to insert
+ * @return a String with the replacements
+ */
+ public static String replace(String inString, String oldPattern, String newPattern) {
+ if (!hasLength(inString) || !hasLength(oldPattern) || newPattern == null) {
+ return inString;
+ }
+ StringBuffer sbuf = new StringBuffer();
+ // output StringBuffer we'll build up
+ int pos = 0; // our position in the old string
+ int index = inString.indexOf(oldPattern);
+ // the index of an occurrence we've found, or -1
+ int patLen = oldPattern.length();
+ while (index >= 0) {
+ sbuf.append(inString.substring(pos, index));
+ sbuf.append(newPattern);
+ pos = index + patLen;
+ index = inString.indexOf(oldPattern, pos);
+ }
+ sbuf.append(inString.substring(pos));
+ // remember to append any characters to the right of a match
+ return sbuf.toString();
+ }
+
+ /**
+ * Delete all occurrences of the given substring.
+ * @param inString the original String
+ * @param pattern the pattern to delete all occurrences of
+ * @return the resulting String
+ */
+ public static String delete(String inString, String pattern) {
+ return replace(inString, pattern, "");
+ }
+
+ /**
+ * Delete any character in a given String.
+ * @param inString the original String
+ * @param charsToDelete a set of characters to delete.
+ * E.g. "az\n" will delete 'a's, 'z's and new lines.
+ * @return the resulting String
+ */
+ public static String deleteAny(String inString, String charsToDelete) {
+ if (!hasLength(inString) || !hasLength(charsToDelete)) {
+ return inString;
+ }
+ StringBuffer out = new StringBuffer();
+ for (int i = 0; i < inString.length(); i++) {
+ char c = inString.charAt(i);
+ if (charsToDelete.indexOf(c) == -1) {
+ out.append(c);
+ }
+ }
+ return out.toString();
+ }
+
+
+ //---------------------------------------------------------------------
+ // Convenience methods for working with formatted Strings
+ //---------------------------------------------------------------------
+
+ /**
+ * Quote the given String with single quotes.
+ * @param str the input String (e.g. "myString")
+ * @return the quoted String (e.g. "'myString'"),
+ * or null if the input was null
+ */
+ public static String quote(String str) {
+ return (str != null ? "'" + str + "'" : null);
+ }
+
+ /**
+ * Turn the given Object into a String with single quotes
+ * if it is a String; keeping the Object as-is else.
+ * @param obj the input Object (e.g. "myString")
+ * @return the quoted String (e.g. "'myString'"),
+ * or the input object as-is if not a String
+ */
+ public static Object quoteIfString(Object obj) {
+ return (obj instanceof String ? quote((String) obj) : obj);
+ }
+
+ /**
+ * Unqualify a string qualified by a '.' dot character. For example,
+ * "this.name.is.qualified", returns "qualified".
+ * @param qualifiedName the qualified name
+ */
+ public static String unqualify(String qualifiedName) {
+ return unqualify(qualifiedName, '.');
+ }
+
+ /**
+ * Unqualify a string qualified by a separator character. For example,
+ * "this:name:is:qualified" returns "qualified" if using a ':' separator.
+ * @param qualifiedName the qualified name
+ * @param separator the separator
+ */
+ public static String unqualify(String qualifiedName, char separator) {
+ return qualifiedName.substring(qualifiedName.lastIndexOf(separator) + 1);
+ }
+
+ /**
+ * Capitalize a String, changing the first letter to
+ * upper case as per {@link Character#toUpperCase(char)}.
+ * No other letters are changed.
+ * @param str the String to capitalize, may be null
+ * @return the capitalized String, null if null
+ */
+ public static String capitalize(String str) {
+ return changeFirstCharacterCase(str, true);
+ }
+
+ /**
+ * Uncapitalize a String, changing the first letter to
+ * lower case as per {@link Character#toLowerCase(char)}.
+ * No other letters are changed.
+ * @param str the String to uncapitalize, may be null
+ * @return the uncapitalized String, null if null
+ */
+ public static String uncapitalize(String str) {
+ return changeFirstCharacterCase(str, false);
+ }
+
+ private static String changeFirstCharacterCase(String str, boolean capitalize) {
+ if (str == null || str.length() == 0) {
+ return str;
+ }
+ StringBuffer buf = new StringBuffer(str.length());
+ if (capitalize) {
+ buf.append(Character.toUpperCase(str.charAt(0)));
+ }
+ else {
+ buf.append(Character.toLowerCase(str.charAt(0)));
+ }
+ buf.append(str.substring(1));
+ return buf.toString();
+ }
+
+ /**
+ * Extract the filename from the given path,
+ * e.g. "mypath/myfile.txt" -> "myfile.txt".
+ * @param path the file path (may be null)
+ * @return the extracted filename, or null if none
+ */
+ public static String getFilename(String path) {
+ if (path == null) {
+ return null;
+ }
+ int separatorIndex = path.lastIndexOf(FOLDER_SEPARATOR);
+ return (separatorIndex != -1 ? path.substring(separatorIndex + 1) : path);
+ }
+
+ /**
+ * Extract the filename extension from the given path,
+ * e.g. "mypath/myfile.txt" -> "txt".
+ * @param path the file path (may be null)
+ * @return the extracted filename extension, or null if none
+ */
+ public static String getFilenameExtension(String path) {
+ if (path == null) {
+ return null;
+ }
+ int sepIndex = path.lastIndexOf(EXTENSION_SEPARATOR);
+ return (sepIndex != -1 ? path.substring(sepIndex + 1) : null);
+ }
+
+ /**
+ * Strip the filename extension from the given path,
+ * e.g. "mypath/myfile.txt" -> "mypath/myfile".
+ * @param path the file path (may be null)
+ * @return the path with stripped filename extension,
+ * or null if none
+ */
+ public static String stripFilenameExtension(String path) {
+ if (path == null) {
+ return null;
+ }
+ int sepIndex = path.lastIndexOf(EXTENSION_SEPARATOR);
+ return (sepIndex != -1 ? path.substring(0, sepIndex) : path);
+ }
+
+ /**
+ * Apply the given relative path to the given path,
+ * assuming standard Java folder separation (i.e. "/" separators);
+ * @param path the path to start from (usually a full file path)
+ * @param relativePath the relative path to apply
+ * (relative to the full file path above)
+ * @return the full file path that results from applying the relative path
+ */
+ public static String applyRelativePath(String path, String relativePath) {
+ int separatorIndex = path.lastIndexOf(FOLDER_SEPARATOR);
+ if (separatorIndex != -1) {
+ String newPath = path.substring(0, separatorIndex);
+ if (!relativePath.startsWith(FOLDER_SEPARATOR)) {
+ newPath += FOLDER_SEPARATOR;
+ }
+ return newPath + relativePath;
+ }
+ else {
+ return relativePath;
+ }
+ }
+
+ /**
+ * Normalize the path by suppressing sequences like "path/.." and
+ * inner simple dots.
+ * The result is convenient for path comparison. For other uses,
+ * notice that Windows separators ("\") are replaced by simple slashes.
+ * @param path the original path
+ * @return the normalized path
+ */
+ public static String cleanPath(String path) {
+ if (path == null) {
+ return null;
+ }
+ String pathToUse = replace(path, WINDOWS_FOLDER_SEPARATOR, FOLDER_SEPARATOR);
+
+ // Strip prefix from path to analyze, to not treat it as part of the
+ // first path element. This is necessary to correctly parse paths like
+ // "file:core/../core/io/Resource.class", where the ".." should just
+ // strip the first "core" directory while keeping the "file:" prefix.
+ int prefixIndex = pathToUse.indexOf(":");
+ String prefix = "";
+ if (prefixIndex != -1) {
+ prefix = pathToUse.substring(0, prefixIndex + 1);
+ pathToUse = pathToUse.substring(prefixIndex + 1);
+ }
+ if (pathToUse.startsWith(FOLDER_SEPARATOR)) {
+ prefix = prefix + FOLDER_SEPARATOR;
+ pathToUse = pathToUse.substring(1);
+ }
+
+ String[] pathArray = delimitedListToStringArray(pathToUse, FOLDER_SEPARATOR);
+ List pathElements = new LinkedList();
+ int tops = 0;
+
+ for (int i = pathArray.length - 1; i >= 0; i--) {
+ String element = pathArray[i];
+ if (CURRENT_PATH.equals(element)) {
+ // Points to current directory - drop it.
+ }
+ else if (TOP_PATH.equals(element)) {
+ // Registering top path found.
+ tops++;
+ }
+ else {
+ if (tops > 0) {
+ // Merging path element with element corresponding to top path.
+ tops--;
+ }
+ else {
+ // Normal path element found.
+ pathElements.add(0, element);
+ }
+ }
+ }
+
+ // Remaining top paths need to be retained.
+ for (int i = 0; i < tops; i++) {
+ pathElements.add(0, TOP_PATH);
+ }
+
+ return prefix + collectionToDelimitedString(pathElements, FOLDER_SEPARATOR);
+ }
+
+ /**
+ * Compare two paths after normalization of them.
+ * @param path1 first path for comparison
+ * @param path2 second path for comparison
+ * @return whether the two paths are equivalent after normalization
+ */
+ public static boolean pathEquals(String path1, String path2) {
+ return cleanPath(path1).equals(cleanPath(path2));
+ }
+
+ /**
+ * Parse the given localeString into a {@link Locale}.
+ *
This is the inverse operation of {@link Locale#toString Locale's toString}.
+ * @param localeString the locale string, following Locale's
+ * toString() format ("en", "en_UK", etc);
+ * also accepts spaces as separators, as an alternative to underscores
+ * @return a corresponding Locale instance
+ */
+ public static Locale parseLocaleString(String localeString) {
+ String[] parts = tokenizeToStringArray(localeString, "_ ", false, false);
+ String language = (parts.length > 0 ? parts[0] : "");
+ String country = (parts.length > 1 ? parts[1] : "");
+ String variant = "";
+ if (parts.length >= 2) {
+ // There is definitely a variant, and it is everything after the country
+ // code sans the separator between the country code and the variant.
+ int endIndexOfCountryCode = localeString.indexOf(country) + country.length();
+ // Strip off any leading '_' and whitespace, what's left is the variant.
+ variant = trimLeadingWhitespace(localeString.substring(endIndexOfCountryCode));
+ if (variant.startsWith("_")) {
+ variant = trimLeadingCharacter(variant, '_');
+ }
+ }
+ return (language.length() > 0 ? new Locale(language, country, variant) : null);
+ }
+
+ /**
+ * Determine the RFC 3066 compliant language tag,
+ * as used for the HTTP "Accept-Language" header.
+ * @param locale the Locale to transform to a language tag
+ * @return the RFC 3066 compliant language tag as String
+ */
+ public static String toLanguageTag(Locale locale) {
+ return locale.getLanguage() + (hasText(locale.getCountry()) ? "-" + locale.getCountry() : "");
+ }
+
+
+ //---------------------------------------------------------------------
+ // Convenience methods for working with String arrays
+ //---------------------------------------------------------------------
+
+ /**
+ * Append the given String to the given String array, returning a new array
+ * consisting of the input array contents plus the given String.
+ * @param array the array to append to (can be null)
+ * @param str the String to append
+ * @return the new array (never null)
+ */
+ public static String[] addStringToArray(String[] array, String str) {
+ if (ObjectUtils.isEmpty(array)) {
+ return new String[] {str};
+ }
+ String[] newArr = new String[array.length + 1];
+ System.arraycopy(array, 0, newArr, 0, array.length);
+ newArr[array.length] = str;
+ return newArr;
+ }
+
+ /**
+ * Concatenate the given String arrays into one,
+ * with overlapping array elements included twice.
+ *
The order of elements in the original arrays is preserved.
+ * @param array1 the first array (can be null)
+ * @param array2 the second array (can be null)
+ * @return the new array (null if both given arrays were null)
+ */
+ public static String[] concatenateStringArrays(String[] array1, String[] array2) {
+ if (ObjectUtils.isEmpty(array1)) {
+ return array2;
+ }
+ if (ObjectUtils.isEmpty(array2)) {
+ return array1;
+ }
+ String[] newArr = new String[array1.length + array2.length];
+ System.arraycopy(array1, 0, newArr, 0, array1.length);
+ System.arraycopy(array2, 0, newArr, array1.length, array2.length);
+ return newArr;
+ }
+
+ /**
+ * Merge the given String arrays into one, with overlapping
+ * array elements only included once.
+ *
The order of elements in the original arrays is preserved
+ * (with the exception of overlapping elements, which are only
+ * included on their first occurence).
+ * @param array1 the first array (can be null)
+ * @param array2 the second array (can be null)
+ * @return the new array (null if both given arrays were null)
+ */
+ public static String[] mergeStringArrays(String[] array1, String[] array2) {
+ if (ObjectUtils.isEmpty(array1)) {
+ return array2;
+ }
+ if (ObjectUtils.isEmpty(array2)) {
+ return array1;
+ }
+ List result = new ArrayList();
+ result.addAll(Arrays.asList(array1));
+ for (int i = 0; i < array2.length; i++) {
+ String str = array2[i];
+ if (!result.contains(str)) {
+ result.add(str);
+ }
+ }
+ return toStringArray(result);
+ }
+
+ /**
+ * Turn given source String array into sorted array.
+ * @param array the source array
+ * @return the sorted array (never null)
+ */
+ public static String[] sortStringArray(String[] array) {
+ if (ObjectUtils.isEmpty(array)) {
+ return new String[0];
+ }
+ Arrays.sort(array);
+ return array;
+ }
+
+ /**
+ * Copy the given Collection into a String array.
+ * The Collection must contain String elements only.
+ * @param collection the Collection to copy
+ * @return the String array (null if the passed-in
+ * Collection was null)
+ */
+ public static String[] toStringArray(Collection collection) {
+ if (collection == null) {
+ return null;
+ }
+ return (String[]) collection.toArray(new String[collection.size()]);
+ }
+
+ /**
+ * Copy the given Enumeration into a String array.
+ * The Enumeration must contain String elements only.
+ * @param enumeration the Enumeration to copy
+ * @return the String array (null if the passed-in
+ * Enumeration was null)
+ */
+ public static String[] toStringArray(Enumeration enumeration) {
+ if (enumeration == null) {
+ return null;
+ }
+ List list = Collections.list(enumeration);
+ return (String[]) list.toArray(new String[list.size()]);
+ }
+
+ /**
+ * Trim the elements of the given String array,
+ * calling String.trim() on each of them.
+ * @param array the original String array
+ * @return the resulting array (of the same size) with trimmed elements
+ */
+ public static String[] trimArrayElements(String[] array) {
+ if (ObjectUtils.isEmpty(array)) {
+ return new String[0];
+ }
+ String[] result = new String[array.length];
+ for (int i = 0; i < array.length; i++) {
+ String element = array[i];
+ result[i] = (element != null ? element.trim() : null);
+ }
+ return result;
+ }
+
+ /**
+ * Remove duplicate Strings from the given array.
+ * Also sorts the array, as it uses a TreeSet.
+ * @param array the String array
+ * @return an array without duplicates, in natural sort order
+ */
+ public static String[] removeDuplicateStrings(String[] array) {
+ if (ObjectUtils.isEmpty(array)) {
+ return array;
+ }
+ Set set = new TreeSet();
+ for (int i = 0; i < array.length; i++) {
+ set.add(array[i]);
+ }
+ return toStringArray(set);
+ }
+
+ /**
+ * Split a String at the first occurrence of the delimiter.
+ * Does not include the delimiter in the result.
+ * @param toSplit the string to split
+ * @param delimiter to split the string up with
+ * @return a two element array with index 0 being before the delimiter, and
+ * index 1 being after the delimiter (neither element includes the delimiter);
+ * or null if the delimiter wasn't found in the given input String
+ */
+ public static String[] split(String toSplit, String delimiter) {
+ if (!hasLength(toSplit) || !hasLength(delimiter)) {
+ return null;
+ }
+ int offset = toSplit.indexOf(delimiter);
+ if (offset < 0) {
+ return null;
+ }
+ String beforeDelimiter = toSplit.substring(0, offset);
+ String afterDelimiter = toSplit.substring(offset + delimiter.length());
+ return new String[] {beforeDelimiter, afterDelimiter};
+ }
+
+ /**
+ * Take an array Strings and split each element based on the given delimiter.
+ * A Properties instance is then generated, with the left of the
+ * delimiter providing the key, and the right of the delimiter providing the value.
+ *
Will trim both the key and value before adding them to the
+ * Properties instance.
+ * @param array the array to process
+ * @param delimiter to split each element using (typically the equals symbol)
+ * @return a Properties instance representing the array contents,
+ * or null if the array to process was null or empty
+ */
+ public static Properties splitArrayElementsIntoProperties(String[] array, String delimiter) {
+ return splitArrayElementsIntoProperties(array, delimiter, null);
+ }
+
+ /**
+ * Take an array Strings and split each element based on the given delimiter.
+ * A Properties instance is then generated, with the left of the
+ * delimiter providing the key, and the right of the delimiter providing the value.
+ *
Will trim both the key and value before adding them to the
+ * Properties instance.
+ * @param array the array to process
+ * @param delimiter to split each element using (typically the equals symbol)
+ * @param charsToDelete one or more characters to remove from each element
+ * prior to attempting the split operation (typically the quotation mark
+ * symbol), or null if no removal should occur
+ * @return a Properties instance representing the array contents,
+ * or null if the array to process was null or empty
+ */
+ public static Properties splitArrayElementsIntoProperties(
+ String[] array, String delimiter, String charsToDelete) {
+
+ if (ObjectUtils.isEmpty(array)) {
+ return null;
+ }
+ Properties result = new Properties();
+ for (int i = 0; i < array.length; i++) {
+ String element = array[i];
+ if (charsToDelete != null) {
+ element = deleteAny(array[i], charsToDelete);
+ }
+ String[] splittedElement = split(element, delimiter);
+ if (splittedElement == null) {
+ continue;
+ }
+ result.setProperty(splittedElement[0].trim(), splittedElement[1].trim());
+ }
+ return result;
+ }
+
+ /**
+ * Tokenize the given String into a String array via a StringTokenizer.
+ * Trims tokens and omits empty tokens.
+ *
The given delimiters string is supposed to consist of any number of
+ * delimiter characters. Each of those characters can be used to separate
+ * tokens. A delimiter is always a single character; for multi-character
+ * delimiters, consider using delimitedListToStringArray
+ * @param str the String to tokenize
+ * @param delimiters the delimiter characters, assembled as String
+ * (each of those characters is individually considered as delimiter).
+ * @return an array of the tokens
+ * @see java.util.StringTokenizer
+ * @see java.lang.String#trim()
+ * @see #delimitedListToStringArray
+ */
+ public static String[] tokenizeToStringArray(String str, String delimiters) {
+ return tokenizeToStringArray(str, delimiters, true, true);
+ }
+
+ /**
+ * Tokenize the given String into a String array via a StringTokenizer.
+ *
The given delimiters string is supposed to consist of any number of
+ * delimiter characters. Each of those characters can be used to separate
+ * tokens. A delimiter is always a single character; for multi-character
+ * delimiters, consider using delimitedListToStringArray
+ * @param str the String to tokenize
+ * @param delimiters the delimiter characters, assembled as String
+ * (each of those characters is individually considered as delimiter)
+ * @param trimTokens trim the tokens via String's trim
+ * @param ignoreEmptyTokens omit empty tokens from the result array
+ * (only applies to tokens that are empty after trimming; StringTokenizer
+ * will not consider subsequent delimiters as token in the first place).
+ * @return an array of the tokens (null if the input String
+ * was null)
+ * @see java.util.StringTokenizer
+ * @see java.lang.String#trim()
+ * @see #delimitedListToStringArray
+ */
+ public static String[] tokenizeToStringArray(
+ String str, String delimiters, boolean trimTokens, boolean ignoreEmptyTokens) {
+
+ if (str == null) {
+ return null;
+ }
+ StringTokenizer st = new StringTokenizer(str, delimiters);
+ List tokens = new ArrayList();
+ while (st.hasMoreTokens()) {
+ String token = st.nextToken();
+ if (trimTokens) {
+ token = token.trim();
+ }
+ if (!ignoreEmptyTokens || token.length() > 0) {
+ tokens.add(token);
+ }
+ }
+ return toStringArray(tokens);
+ }
+
+ /**
+ * Take a String which is a delimited list and convert it to a String array.
+ *
A single delimiter can consists of more than one character: It will still
+ * be considered as single delimiter string, rather than as bunch of potential
+ * delimiter characters - in contrast to tokenizeToStringArray.
+ * @param str the input String
+ * @param delimiter the delimiter between elements (this is a single delimiter,
+ * rather than a bunch individual delimiter characters)
+ * @return an array of the tokens in the list
+ * @see #tokenizeToStringArray
+ */
+ public static String[] delimitedListToStringArray(String str, String delimiter) {
+ return delimitedListToStringArray(str, delimiter, null);
+ }
+
+ /**
+ * Take a String which is a delimited list and convert it to a String array.
+ *
A single delimiter can consists of more than one character: It will still
+ * be considered as single delimiter string, rather than as bunch of potential
+ * delimiter characters - in contrast to tokenizeToStringArray.
+ * @param str the input String
+ * @param delimiter the delimiter between elements (this is a single delimiter,
+ * rather than a bunch individual delimiter characters)
+ * @param charsToDelete a set of characters to delete. Useful for deleting unwanted
+ * line breaks: e.g. "\r\n\f" will delete all new lines and line feeds in a String.
+ * @return an array of the tokens in the list
+ * @see #tokenizeToStringArray
+ */
+ public static String[] delimitedListToStringArray(String str, String delimiter, String charsToDelete) {
+ if (str == null) {
+ return new String[0];
+ }
+ if (delimiter == null) {
+ return new String[] {str};
+ }
+ List result = new ArrayList();
+ if ("".equals(delimiter)) {
+ for (int i = 0; i < str.length(); i++) {
+ result.add(deleteAny(str.substring(i, i + 1), charsToDelete));
+ }
+ }
+ else {
+ int pos = 0;
+ int delPos = 0;
+ while ((delPos = str.indexOf(delimiter, pos)) != -1) {
+ result.add(deleteAny(str.substring(pos, delPos), charsToDelete));
+ pos = delPos + delimiter.length();
+ }
+ if (str.length() > 0 && pos <= str.length()) {
+ // Add rest of String, but not in case of empty input.
+ result.add(deleteAny(str.substring(pos), charsToDelete));
+ }
+ }
+ return toStringArray(result);
+ }
+
+ /**
+ * Convert a CSV list into an array of Strings.
+ * @param str the input String
+ * @return an array of Strings, or the empty array in case of empty input
+ */
+ public static String[] commaDelimitedListToStringArray(String str) {
+ return delimitedListToStringArray(str, ",");
+ }
+
+ /**
+ * Convenience method to convert a CSV string list to a set.
+ * Note that this will suppress duplicates.
+ * @param str the input String
+ * @return a Set of String entries in the list
+ */
+ public static Set commaDelimitedListToSet(String str) {
+ Set set = new TreeSet();
+ String[] tokens = commaDelimitedListToStringArray(str);
+ for (int i = 0; i < tokens.length; i++) {
+ set.add(tokens[i]);
+ }
+ return set;
+ }
+
+ /**
+ * Convenience method to return a Collection as a delimited (e.g. CSV)
+ * String. E.g. useful for toString() implementations.
+ * @param coll the Collection to display
+ * @param delim the delimiter to use (probably a ",")
+ * @param prefix the String to start each element with
+ * @param suffix the String to end each element with
+ * @return the delimited String
+ */
+ public static String collectionToDelimitedString(Collection coll, String delim, String prefix, String suffix) {
+ if (CollectionUtils.isEmpty(coll)) {
+ return "";
+ }
+ StringBuffer sb = new StringBuffer();
+ Iterator it = coll.iterator();
+ while (it.hasNext()) {
+ sb.append(prefix).append(it.next()).append(suffix);
+ if (it.hasNext()) {
+ sb.append(delim);
+ }
+ }
+ return sb.toString();
+ }
+
+ /**
+ * Convenience method to return a Collection as a delimited (e.g. CSV)
+ * String. E.g. useful for toString() implementations.
+ * @param coll the Collection to display
+ * @param delim the delimiter to use (probably a ",")
+ * @return the delimited String
+ */
+ public static String collectionToDelimitedString(Collection coll, String delim) {
+ return collectionToDelimitedString(coll, delim, "", "");
+ }
+
+ /**
+ * Convenience method to return a Collection as a CSV String.
+ * E.g. useful for toString() implementations.
+ * @param coll the Collection to display
+ * @return the delimited String
+ */
+ public static String collectionToCommaDelimitedString(Collection coll) {
+ return collectionToDelimitedString(coll, ",");
+ }
+
+ /**
+ * Convenience method to return a String array as a delimited (e.g. CSV)
+ * String. E.g. useful for toString() implementations.
+ * @param arr the array to display
+ * @param delim the delimiter to use (probably a ",")
+ * @return the delimited String
+ */
+ public static String arrayToDelimitedString(Object[] arr, String delim) {
+ if (ObjectUtils.isEmpty(arr)) {
+ return "";
+ }
+ StringBuffer sb = new StringBuffer();
+ for (int i = 0; i < arr.length; i++) {
+ if (i > 0) {
+ sb.append(delim);
+ }
+ sb.append(arr[i]);
+ }
+ return sb.toString();
+ }
+
+ /**
+ * Convenience method to return a String array as a CSV String.
+ * E.g. useful for toString() implementations.
+ * @param arr the array to display
+ * @return the delimited String
+ */
+ public static String arrayToCommaDelimitedString(Object[] arr) {
+ return arrayToDelimitedString(arr, ",");
+ }
+
+}