package org.googlecode.perftrace.util;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;
import java.util.Locale;
import java.util.Properties;
import java.util.Set;
import java.util.StringTokenizer;
import java.util.TreeSet;
public class StringUtils {
/**
* The empty String <code>""</code>.
*
* @since 2.0
*/
public static final String EMPTY = "";
/**
* An empty immutable <code>String</code> array.
*/
public static final String[] EMPTY_STRING_ARRAY = new String[0];
// startsWith
// -----------------------------------------------------------------------
/**
* <p>
* Check if a String starts with a specified prefix.
* </p>
*
* <p>
* <code>null</code>s are handled without exceptions. Two <code>null</code>
* references are considered to be equal. The comparison is case sensitive.
* </p>
*
* <pre>
* StringUtils.startsWith(null, null) = true
* StringUtils.startsWith(null, "abc") = false
* StringUtils.startsWith("abcdef", null) = false
* StringUtils.startsWith("abcdef", "abc") = true
* StringUtils.startsWith("ABCDEF", "abc") = false
* </pre>
*
* @see java.lang.String#startsWith(String)
* @param str
* the String to check, may be null
* @param prefix
* the prefix to find, may be null
* @return <code>true</code> if the String starts with the prefix, case
* sensitive, or both <code>null</code>
* @since 2.4
*/
public static boolean startsWith(String str, String prefix) {
return startsWith(str, prefix, false);
}
/**
* <p>
* Case insensitive check if a String starts with a specified prefix.
* </p>
*
* <p>
* <code>null</code>s are handled without exceptions. Two <code>null</code>
* references are considered to be equal. The comparison is case
* insensitive.
* </p>
*
* <pre>
* StringUtils.startsWithIgnoreCase(null, null) = true
* StringUtils.startsWithIgnoreCase(null, "abc") = false
* StringUtils.startsWithIgnoreCase("abcdef", null) = false
* StringUtils.startsWithIgnoreCase("abcdef", "abc") = true
* StringUtils.startsWithIgnoreCase("ABCDEF", "abc") = true
* </pre>
*
* @see java.lang.String#startsWith(String)
* @param str
* the String to check, may be null
* @param prefix
* the prefix to find, may be null
* @return <code>true</code> if the String starts with the prefix, case
* insensitive, or both <code>null</code>
* @since 2.4
*/
public static boolean startsWithIgnoreCase(String str, String prefix) {
return startsWith(str, prefix, true);
}
/**
* <p>
* Check if a String starts with a specified prefix (optionally case
* insensitive).
* </p>
*
* @see java.lang.String#startsWith(String)
* @param str
* the String to check, may be null
* @param prefix
* the prefix to find, may be null
* @param ignoreCase
* inidicates whether the compare should ignore case (case
* insensitive) or not.
* @return <code>true</code> if the String starts with the prefix or both
* <code>null</code>
*/
private static boolean startsWith(String str, String prefix,
boolean ignoreCase) {
if (str == null || prefix == null) {
return (str == null && prefix == null);
}
if (prefix.length() > str.length()) {
return false;
}
return str.regionMatches(ignoreCase, 0, prefix, 0, prefix.length());
}
// Splitting
// -----------------------------------------------------------------------
/**
* <p>
* Splits the provided text into an array, using whitespace as the
* separator. Whitespace is defined by {@link Character#isWhitespace(char)}.
* </p>
*
* <p>
* The separator is not included in the returned String array. Adjacent
* separators are treated as one separator. For more control over the split
* use the StrTokenizer class.
* </p>
*
* <p>
* A <code>null</code> input String returns <code>null</code>.
* </p>
*
* <pre>
* StringUtils.split(null) = null
* StringUtils.split("") = []
* StringUtils.split("abc def") = ["abc", "def"]
* StringUtils.split("abc def") = ["abc", "def"]
* StringUtils.split(" abc ") = ["abc"]
* </pre>
*
* @param str
* the String to parse, may be null
* @return an array of parsed Strings, <code>null</code> if null String
* input
*/
public static String[] split(String str) {
return split(str, null, -1);
}
/**
* <p>
* Splits the provided text into an array, separators specified. This is an
* alternative to using StringTokenizer.
* </p>
*
* <p>
* The separator is not included in the returned String array. Adjacent
* separators are treated as one separator. For more control over the split
* use the StrTokenizer class.
* </p>
*
* <p>
* A <code>null</code> input String returns <code>null</code>. A
* <code>null</code> separatorChars splits on whitespace.
* </p>
*
* <pre>
* StringUtils.split(null, *) = null
* StringUtils.split("", *) = []
* StringUtils.split("abc def", null) = ["abc", "def"]
* StringUtils.split("abc def", " ") = ["abc", "def"]
* StringUtils.split("abc def", " ") = ["abc", "def"]
* StringUtils.split("ab:cd:ef", ":") = ["ab", "cd", "ef"]
* </pre>
*
* @param str
* the String to parse, may be null
* @param separatorChars
* the characters used as the delimiters, <code>null</code>
* splits on whitespace
* @return an array of parsed Strings, <code>null</code> if null String
* input
*/
public static String[] split(String str, String separatorChars) {
return splitWorker(str, separatorChars, -1, false);
}
/**
* <p>
* Splits the provided text into an array with a maximum length, separators
* specified.
* </p>
*
* <p>
* The separator is not included in the returned String array. Adjacent
* separators are treated as one separator.
* </p>
*
* <p>
* A <code>null</code> input String returns <code>null</code>. A
* <code>null</code> separatorChars splits on whitespace.
* </p>
*
* <p>
* If more than <code>max</code> delimited substrings are found, the last
* returned string includes all characters after the first
* <code>max - 1</code> returned strings (including separator characters).
* </p>
*
* <pre>
* StringUtils.split(null, *, *) = null
* StringUtils.split("", *, *) = []
* StringUtils.split("ab de fg", null, 0) = ["ab", "cd", "ef"]
* StringUtils.split("ab de fg", null, 0) = ["ab", "cd", "ef"]
* StringUtils.split("ab:cd:ef", ":", 0) = ["ab", "cd", "ef"]
* StringUtils.split("ab:cd:ef", ":", 2) = ["ab", "cd:ef"]
* </pre>
*
* @param str
* the String to parse, may be null
* @param separatorChars
* the characters used as the delimiters, <code>null</code>
* splits on whitespace
* @param max
* the maximum number of elements to include in the array. A zero
* or negative value implies no limit
* @return an array of parsed Strings, <code>null</code> if null String
* input
*/
public static String[] split(String str, String separatorChars, int max) {
return splitWorker(str, separatorChars, max, false);
}
/**
* Performs the logic for the <code>split</code> and
* <code>splitPreserveAllTokens</code> methods that return a maximum array
* length.
*
* @param str
* the String to parse, may be <code>null</code>
* @param separatorChars
* the separate character
* @param max
* the maximum number of elements to include in the array. A zero
* or negative value implies no limit.
* @param preserveAllTokens
* if <code>true</code>, adjacent separators are treated as empty
* token separators; if <code>false</code>, adjacent separators
* are treated as one separator.
* @return an array of parsed Strings, <code>null</code> if null String
* input
*/
private static String[] splitWorker(String str, String separatorChars,
int max, boolean preserveAllTokens) {
// Performance tuned for 2.0 (JDK1.4)
// Direct code is quicker than StringTokenizer.
// Also, StringTokenizer uses isSpace() not isWhitespace()
if (str == null) {
return null;
}
int len = str.length();
if (len == 0) {
return EMPTY_STRING_ARRAY;
}
List list = new ArrayList();
int sizePlus1 = 1;
int i = 0, start = 0;
boolean match = false;
boolean lastMatch = false;
if (separatorChars == null) {
// Null separator means use whitespace
while (i < len) {
if (Character.isWhitespace(str.charAt(i))) {
if (match || preserveAllTokens) {
lastMatch = true;
if (sizePlus1++ == max) {
i = len;
lastMatch = false;
}
list.add(str.substring(start, i));
match = false;
}
start = ++i;
continue;
}
lastMatch = false;
match = true;
i++;
}
} else if (separatorChars.length() == 1) {
// Optimise 1 character case
char sep = separatorChars.charAt(0);
while (i < len) {
if (str.charAt(i) == sep) {
if (match || preserveAllTokens) {
lastMatch = true;
if (sizePlus1++ == max) {
i = len;
lastMatch = false;
}
list.add(str.substring(start, i));
match = false;
}
start = ++i;
continue;
}
lastMatch = false;
match = true;
i++;
}
} else {
// standard case
while (i < len) {
if (separatorChars.indexOf(str.charAt(i)) >= 0) {
if (match || preserveAllTokens) {
lastMatch = true;
if (sizePlus1++ == max) {
i = len;
lastMatch = false;
}
list.add(str.substring(start, i));
match = false;
}
start = ++i;
continue;
}
lastMatch = false;
match = true;
i++;
}
}
if (match || (preserveAllTokens && lastMatch)) {
list.add(str.substring(start, i));
}
return (String[]) list.toArray(new String[list.size()]);
}
/**
* <p>
* Joins the elements of the provided array into a single String containing
* the provided list of elements.
* </p>
*
* <p>
* No delimiter is added before or after the list. A <code>null</code>
* separator is the same as an empty String (""). Null objects or empty
* strings within the array are represented by empty strings.
* </p>
*
* <pre>
* StringUtils.join(null, *) = null
* StringUtils.join([], *) = ""
* StringUtils.join([null], *) = ""
* StringUtils.join(["a", "b", "c"], "--") = "a--b--c"
* StringUtils.join(["a", "b", "c"], null) = "abc"
* StringUtils.join(["a", "b", "c"], "") = "abc"
* StringUtils.join([null, "", "a"], ',') = ",,a"
* </pre>
*
* @param array
* the array of values to join together, may be null
* @param separator
* the separator character to use, null treated as ""
* @return the joined String, <code>null</code> if null array input
*/
public static String join(Object[] array, String separator) {
if (array == null) {
return null;
}
return join(array, separator, 0, array.length);
}
/**
* <p>
* Joins the elements of the provided array into a single String containing
* the provided list of elements.
* </p>
*
* <p>
* No delimiter is added before or after the list. A <code>null</code>
* separator is the same as an empty String (""). Null objects or empty
* strings within the array are represented by empty strings.
* </p>
*
* <pre>
* StringUtils.join(null, *) = null
* StringUtils.join([], *) = ""
* StringUtils.join([null], *) = ""
* StringUtils.join(["a", "b", "c"], "--") = "a--b--c"
* StringUtils.join(["a", "b", "c"], null) = "abc"
* StringUtils.join(["a", "b", "c"], "") = "abc"
* StringUtils.join([null, "", "a"], ',') = ",,a"
* </pre>
*
* @param array
* the array of values to join together, may be null
* @param separator
* the separator character to use, null treated as ""
* @param startIndex
* the first index to start joining from. It is an error to pass
* in an end index past the end of the array
* @param endIndex
* the index to stop joining from (exclusive). It is an error to
* pass in an end index past the end of the array
* @return the joined String, <code>null</code> if null array input
*/
public static String join(Object[] array, String separator, int startIndex,
int endIndex) {
if (array == null) {
return null;
}
if (separator == null) {
separator = EMPTY;
}
// endIndex - startIndex > 0: Len = NofStrings *(len(firstString) +
// len(separator))
// (Assuming that all Strings are roughly equally long)
int bufSize = (endIndex - startIndex);
if (bufSize <= 0) {
return EMPTY;
}
bufSize *= ((array[startIndex] == null ? 16 : array[startIndex]
.toString().length()) + separator.length());
StringBuffer buf = new StringBuffer(bufSize);
for (int i = startIndex; i < endIndex; i++) {
if (i > startIndex) {
buf.append(separator);
}
if (array[i] != null) {
buf.append(array[i]);
}
}
return buf.toString();
}
/**
* <p>
* Checks if a String is whitespace, empty ("") or null.
* </p>
*
* <pre>
* StringUtils.isBlank(null) = true
* StringUtils.isBlank("") = true
* StringUtils.isBlank(" ") = true
* StringUtils.isBlank("bob") = false
* StringUtils.isBlank(" bob ") = false
* </pre>
*
* @param str
* the String to check, may be null
* @return <code>true</code> if the String is null, empty or whitespace
* @since 2.0
*/
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)) == false)) {
return false;
}
}
return true;
}
// Stripping
// -----------------------------------------------------------------------
/**
* <p>
* Strips whitespace from the start and end of a String.
* </p>
*
* <p>
* This is similar to {@link #trim(String)} but removes whitespace.
* Whitespace is defined by {@link Character#isWhitespace(char)}.
* </p>
*
* <p>
* A <code>null</code> input String returns <code>null</code>.
* </p>
*
* <pre>
* StringUtils.strip(null) = null
* StringUtils.strip("") = ""
* StringUtils.strip(" ") = ""
* StringUtils.strip("abc") = "abc"
* StringUtils.strip(" abc") = "abc"
* StringUtils.strip("abc ") = "abc"
* StringUtils.strip(" abc ") = "abc"
* StringUtils.strip(" ab c ") = "ab c"
* </pre>
*
* @param str
* the String to remove whitespace from, may be null
* @return the stripped String, <code>null</code> if null String input
*/
public static String strip(String str) {
return strip(str, null);
}
/**
* <p>
* Strips whitespace from the start and end of a String returning
* <code>null</code> if the String is empty ("") after the strip.
* </p>
*
* <p>
* This is similar to {@link #trimToNull(String)} but removes whitespace.
* Whitespace is defined by {@link Character#isWhitespace(char)}.
* </p>
*
* <pre>
* StringUtils.stripToNull(null) = null
* StringUtils.stripToNull("") = null
* StringUtils.stripToNull(" ") = null
* StringUtils.stripToNull("abc") = "abc"
* StringUtils.stripToNull(" abc") = "abc"
* StringUtils.stripToNull("abc ") = "abc"
* StringUtils.stripToNull(" abc ") = "abc"
* StringUtils.stripToNull(" ab c ") = "ab c"
* </pre>
*
* @param str
* the String to be stripped, may be null
* @return the stripped String, <code>null</code> if whitespace, empty or
* null String input
* @since 2.0
*/
public static String stripToNull(String str) {
if (str == null) {
return null;
}
str = strip(str, null);
return str.length() == 0 ? null : str;
}
/**
* <p>
* Strips whitespace from the start and end of a String returning an empty
* String if <code>null</code> input.
* </p>
*
* <p>
* This is similar to {@link #trimToEmpty(String)} but removes whitespace.
* Whitespace is defined by {@link Character#isWhitespace(char)}.
* </p>
*
* <pre>
* StringUtils.stripToEmpty(null) = ""
* StringUtils.stripToEmpty("") = ""
* StringUtils.stripToEmpty(" ") = ""
* StringUtils.stripToEmpty("abc") = "abc"
* StringUtils.stripToEmpty(" abc") = "abc"
* StringUtils.stripToEmpty("abc ") = "abc"
* StringUtils.stripToEmpty(" abc ") = "abc"
* StringUtils.stripToEmpty(" ab c ") = "ab c"
* </pre>
*
* @param str
* the String to be stripped, may be null
* @return the trimmed String, or an empty String if <code>null</code> input
* @since 2.0
*/
public static String stripToEmpty(String str) {
return str == null ? EMPTY : strip(str, null);
}
/**
* <p>
* Strips any of a set of characters from the start and end of a String.
* This is similar to {@link String#trim()} but allows the characters to be
* stripped to be controlled.
* </p>
*
* <p>
* A <code>null</code> input String returns <code>null</code>. An empty
* string ("") input returns the empty string.
* </p>
*
* <p>
* If the stripChars String is <code>null</code>, whitespace is stripped as
* defined by {@link Character#isWhitespace(char)}. Alternatively use
* {@link #strip(String)}.
* </p>
*
* <pre>
* StringUtils.strip(null, *) = null
* StringUtils.strip("", *) = ""
* StringUtils.strip("abc", null) = "abc"
* StringUtils.strip(" abc", null) = "abc"
* StringUtils.strip("abc ", null) = "abc"
* StringUtils.strip(" abc ", null) = "abc"
* StringUtils.strip(" abcyx", "xyz") = " abc"
* </pre>
*
* @param str
* the String to remove characters from, may be null
* @param stripChars
* the characters to remove, null treated as whitespace
* @return the stripped String, <code>null</code> if null String input
*/
public static String strip(String str, String stripChars) {
if (isEmpty(str)) {
return str;
}
str = stripStart(str, stripChars);
return stripEnd(str, stripChars);
}
/**
* <p>
* Strips any of a set of characters from the start of a String.
* </p>
*
* <p>
* A <code>null</code> input String returns <code>null</code>. An empty
* string ("") input returns the empty string.
* </p>
*
* <p>
* If the stripChars String is <code>null</code>, whitespace is stripped as
* defined by {@link Character#isWhitespace(char)}.
* </p>
*
* <pre>
* StringUtils.stripStart(null, *) = null
* StringUtils.stripStart("", *) = ""
* StringUtils.stripStart("abc", "") = "abc"
* StringUtils.stripStart("abc", null) = "abc"
* StringUtils.stripStart(" abc", null) = "abc"
* StringUtils.stripStart("abc ", null) = "abc "
* StringUtils.stripStart(" abc ", null) = "abc "
* StringUtils.stripStart("yxabc ", "xyz") = "abc "
* </pre>
*
* @param str
* the String to remove characters from, may be null
* @param stripChars
* the characters to remove, null treated as whitespace
* @return the stripped String, <code>null</code> if null String input
*/
public static String stripStart(String str, String stripChars) {
int strLen;
if (str == null || (strLen = str.length()) == 0) {
return str;
}
int start = 0;
if (stripChars == null) {
while ((start != strLen)
&& Character.isWhitespace(str.charAt(start))) {
start++;
}
} else if (stripChars.length() == 0) {
return str;
} else {
while ((start != strLen)
&& (stripChars.indexOf(str.charAt(start)) != -1)) {
start++;
}
}
return str.substring(start);
}
/**
* <p>
* Strips any of a set of characters from the end of a String.
* </p>
*
* <p>
* A <code>null</code> input String returns <code>null</code>. An empty
* string ("") input returns the empty string.
* </p>
*
* <p>
* If the stripChars String is <code>null</code>, whitespace is stripped as
* defined by {@link Character#isWhitespace(char)}.
* </p>
*
* <pre>
* StringUtils.stripEnd(null, *) = null
* StringUtils.stripEnd("", *) = ""
* StringUtils.stripEnd("abc", "") = "abc"
* StringUtils.stripEnd("abc", null) = "abc"
* StringUtils.stripEnd(" abc", null) = " abc"
* StringUtils.stripEnd("abc ", null) = "abc"
* StringUtils.stripEnd(" abc ", null) = " abc"
* StringUtils.stripEnd(" abcyx", "xyz") = " abc"
* </pre>
*
* @param str
* the String to remove characters from, may be null
* @param stripChars
* the characters to remove, null treated as whitespace
* @return the stripped String, <code>null</code> if null String input
*/
public static String stripEnd(String str, String stripChars) {
int end;
if (str == null || (end = str.length()) == 0) {
return str;
}
if (stripChars == null) {
while ((end != 0) && Character.isWhitespace(str.charAt(end - 1))) {
end--;
}
} else if (stripChars.length() == 0) {
return str;
} else {
while ((end != 0)
&& (stripChars.indexOf(str.charAt(end - 1)) != -1)) {
end--;
}
}
return str.substring(0, end);
}
// Empty checks
// -----------------------------------------------------------------------
/**
* <p>
* Checks if a String is empty ("") or null.
* </p>
*
* <pre>
* StringUtils.isEmpty(null) = true
* StringUtils.isEmpty("") = true
* StringUtils.isEmpty(" ") = false
* StringUtils.isEmpty("bob") = false
* StringUtils.isEmpty(" bob ") = false
* </pre>
*
* <p>
* NOTE: This method changed in Lang version 2.0. It no longer trims the
* String. That functionality is available in isBlank().
* </p>
*
* @param str
* the String to check, may be null
* @return <code>true</code> if the String is empty or null
*/
public static boolean isEmpty(String str) {
return str == null || str.length() == 0;
}
// Equals
// -----------------------------------------------------------------------
/**
* <p>
* Compares two Strings, returning <code>true</code> if they are equal.
* </p>
*
* <p>
* <code>null</code>s are handled without exceptions. Two <code>null</code>
* references are considered to be equal. The comparison is case sensitive.
* </p>
*
* <pre>
* StringUtils.equals(null, null) = true
* StringUtils.equals(null, "abc") = false
* StringUtils.equals("abc", null) = false
* StringUtils.equals("abc", "abc") = true
* StringUtils.equals("abc", "ABC") = false
* </pre>
*
* @see java.lang.String#equals(Object)
* @param str1
* the first String, may be null
* @param str2
* the second String, may be null
* @return <code>true</code> if the Strings are equal, case sensitive, or
* both <code>null</code>
*/
public static boolean equals(String str1, String str2) {
return str1 == null ? str2 == null : str1.equals(str2);
}
/**
* <p>
* Compares two Strings, returning <code>true</code> if they are equal
* ignoring the case.
* </p>
*
* <p>
* <code>null</code>s are handled without exceptions. Two <code>null</code>
* references are considered equal. Comparison is case insensitive.
* </p>
*
* <pre>
* StringUtils.equalsIgnoreCase(null, null) = true
* StringUtils.equalsIgnoreCase(null, "abc") = false
* StringUtils.equalsIgnoreCase("abc", null) = false
* StringUtils.equalsIgnoreCase("abc", "abc") = true
* StringUtils.equalsIgnoreCase("abc", "ABC") = true
* </pre>
*
* @see java.lang.String#equalsIgnoreCase(String)
* @param str1
* the first String, may be null
* @param str2
* the second String, may be null
* @return <code>true</code> if the Strings are equal, case insensitive, or
* both <code>null</code>
*/
public static boolean equalsIgnoreCase(String str1, String str2) {
return str1 == null ? str2 == null : str1.equalsIgnoreCase(str2);
}
/**
* <p>Joins the elements of the provided <code>Iterator</code> into
* a single String containing the provided elements.</p>
*
* <p>No delimiter is added before or after the list.
* A <code>null</code> separator is the same as an empty String ("").</p>
*
* <p>See the examples here: {@link #join(Object[],String)}. </p>
*
* @param iterator the <code>Iterator</code> of values to join together, may be null
* @param separator the separator character to use, null treated as ""
* @return the joined String, <code>null</code> if null iterator input
*/
public static String join(Iterator iterator, String separator) {
// handle null, zero and one elements before building a buffer
if (iterator == null) {
return null;
}
if (!iterator.hasNext()) {
return EMPTY;
}
Object first = iterator.next();
if (!iterator.hasNext()) {
return first == null ? "" : first.toString();
}
// two or more elements
StringBuffer buf = new StringBuffer(256); // Java default is 16, probably too small
if (first != null) {
buf.append(first);
}
while (iterator.hasNext()) {
if (separator != null) {
buf.append(separator);
}
Object obj = iterator.next();
if (obj != null) {
buf.append(obj);
}
}
return buf.toString();
}
/**
* <p>Joins the elements of the provided <code>Collection</code> into
* a single String containing the provided elements.</p>
*
* <p>No delimiter is added before or after the list.
* A <code>null</code> separator is the same as an empty String ("").</p>
*
* <p>See the examples here: {@link #join(Object[],String)}. </p>
*
* @param collection the <code>Collection</code> of values to join together, may be null
* @param separator the separator character to use, null treated as ""
* @return the joined String, <code>null</code> if null iterator input
* @since 2.3
*/
public static String join(Collection collection, String separator) {
if (collection == null) {
return null;
}
return join(collection.iterator(), separator);
}
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 whether the given String is empty.
* <p>This method accepts any Object as an argument, comparing it to
* {@code null} and the empty String. As a consequence, this method
* will never return {@code true} for a non-null non-String object.
* <p>The Object signature is useful for general attribute handling code
* that commonly deals with Strings but generally has to iterate over
* Objects since attributes may e.g. be primitive value objects as well.
* @param str the candidate String
* @since 3.2.1
*/
public static boolean isEmpty(Object str) {
return (str == null || "".equals(str));
}
/**
* Check that the given CharSequence is neither {@code null} nor of length 0.
* Note: Will return {@code true} for a CharSequence that purely consists of whitespace.
* <p><pre>
* StringUtils.hasLength(null) = false
* StringUtils.hasLength("") = false
* StringUtils.hasLength(" ") = true
* StringUtils.hasLength("Hello") = true
* </pre>
* @param str the CharSequence to check (may be {@code null})
* @return {@code 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 {@code null} nor of length 0.
* Note: Will return {@code true} for a String that purely consists of whitespace.
* @param str the String to check (may be {@code null})
* @return {@code 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 {@code true} if the string not {@code null},
* its length is greater than 0, and it contains at least one non-whitespace character.
* <p><pre>
* StringUtils.hasText(null) = false
* StringUtils.hasText("") = false
* StringUtils.hasText(" ") = false
* StringUtils.hasText("12345") = true
* StringUtils.hasText(" 12345 ") = true
* </pre>
* @param str the CharSequence to check (may be {@code null})
* @return {@code true} if the CharSequence is not {@code null},
* its length is greater than 0, and it does not contain whitespace only
* @see 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 {@code true} if the string not {@code null},
* its length is greater than 0, and it contains at least one non-whitespace character.
* @param str the String to check (may be {@code null})
* @return {@code true} if the String is not {@code 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 {@code null})
* @return {@code true} if the CharSequence is not empty and
* contains at least 1 whitespace character
* @see 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 {@code null})
* @return {@code 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;
}
StringBuilder sb = new StringBuilder(str);
while (sb.length() > 0 && Character.isWhitespace(sb.charAt(0))) {
sb.deleteCharAt(0);
}
while (sb.length() > 0 && Character.isWhitespace(sb.charAt(sb.length() - 1))) {
sb.deleteCharAt(sb.length() - 1);
}
return sb.toString();
}
/**
* Trim <i>all</i> 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;
}
StringBuilder sb = new StringBuilder(str);
int index = 0;
while (sb.length() > index) {
if (Character.isWhitespace(sb.charAt(index))) {
sb.deleteCharAt(index);
}
else {
index++;
}
}
return sb.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;
}
StringBuilder sb = new StringBuilder(str);
while (sb.length() > 0 && Character.isWhitespace(sb.charAt(0))) {
sb.deleteCharAt(0);
}
return sb.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;
}
StringBuilder sb = new StringBuilder(str);
while (sb.length() > 0 && Character.isWhitespace(sb.charAt(sb.length() - 1))) {
sb.deleteCharAt(sb.length() - 1);
}
return sb.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;
}
StringBuilder sb = new StringBuilder(str);
while (sb.length() > 0 && sb.charAt(0) == leadingCharacter) {
sb.deleteCharAt(0);
}
return sb.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;
}
StringBuilder sb = new StringBuilder(str);
while (sb.length() > 0 && sb.charAt(sb.length() - 1) == trailingCharacter) {
sb.deleteCharAt(sb.length() - 1);
}
return sb.toString();
}
/**
* 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 StringBuilder)
* @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;
int pos = 0;
int idx;
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;
}
StringBuilder sb = new StringBuilder();
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) {
sb.append(inString.substring(pos, index));
sb.append(newPattern);
pos = index + patLen;
index = inString.indexOf(oldPattern, pos);
}
sb.append(inString.substring(pos));
// remember to append any characters to the right of a match
return sb.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;
}
StringBuilder sb = new StringBuilder();
for (int i = 0; i < inString.length(); i++) {
char c = inString.charAt(i);
if (charsToDelete.indexOf(c) == -1) {
sb.append(c);
}
}
return sb.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 {@code null} if the input was {@code 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 {@code 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 {@code null}
* @return the capitalized String, {@code null} if null
*/
public static String capitalize(String str) {
return changeFirstCharacterCase(str, true);
}
/**
* Uncapitalize a {@code 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 {@code null}
* @return the uncapitalized String, {@code 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;
}
StringBuilder sb = new StringBuilder(str.length());
if (capitalize) {
sb.append(Character.toUpperCase(str.charAt(0)));
}
else {
sb.append(Character.toLowerCase(str.charAt(0)));
}
sb.append(str.substring(1));
return sb.toString();
}
/**
* Extract the filename from the given path,
* e.g. "mypath/myfile.txt" -> "myfile.txt".
* @param path the file path (may be {@code null})
* @return the extracted filename, or {@code 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 {@code null})
* @return the extracted filename extension, or {@code null} if none
*/
public static String getFilenameExtension(String path) {
if (path == null) {
return null;
}
int extIndex = path.lastIndexOf(EXTENSION_SEPARATOR);
if (extIndex == -1) {
return null;
}
int folderIndex = path.lastIndexOf(FOLDER_SEPARATOR);
if (folderIndex > extIndex) {
return null;
}
return path.substring(extIndex + 1);
}
/**
* Strip the filename extension from the given path,
* e.g. "mypath/myfile.txt" -> "mypath/myfile".
* @param path the file path (may be {@code null})
* @return the path with stripped filename extension,
* or {@code null} if none
*/
public static String stripFilenameExtension(String path) {
if (path == null) {
return null;
}
int extIndex = path.lastIndexOf(EXTENSION_SEPARATOR);
if (extIndex == -1) {
return path;
}
int folderIndex = path.lastIndexOf(FOLDER_SEPARATOR);
if (folderIndex > extIndex) {
return path;
}
return path.substring(0, extIndex);
}
/**
* Parse the given {@code localeString} value into a {@link Locale}.
* <p>This is the inverse operation of {@link Locale#toString Locale's toString}.
* @param localeString the locale string, following {@code Locale's}
* {@code toString()} format ("en", "en_UK", etc);
* also accepts spaces as separators, as an alternative to underscores
* @return a corresponding {@code 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] : "");
validateLocalePart(language);
validateLocalePart(country);
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.lastIndexOf(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);
}
private static void validateLocalePart(String localePart) {
for (int i = 0; i < localePart.length(); i++) {
char ch = localePart.charAt(i);
if (ch != '_' && ch != ' ' && !Character.isLetterOrDigit(ch)) {
throw new IllegalArgumentException(
"Locale part \"" + localePart + "\" contains invalid characters");
}
}
}
/**
* 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 {@code null})
* @param str the String to append
* @return the new array (never {@code 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.
* <p>The order of elements in the original arrays is preserved.
* @param array1 the first array (can be {@code null})
* @param array2 the second array (can be {@code null})
* @return the new array ({@code null} if both given arrays were {@code 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.
* <p>The order of elements in the original arrays is preserved
* (with the exception of overlapping elements, which are only
* included on their first occurrence).
* @param array1 the first array (can be {@code null})
* @param array2 the second array (can be {@code null})
* @return the new array ({@code null} if both given arrays were {@code null})
*/
public static String[] mergeStringArrays(String[] array1, String[] array2) {
if (ObjectUtils.isEmpty(array1)) {
return array2;
}
if (ObjectUtils.isEmpty(array2)) {
return array1;
}
List<String> result = new ArrayList<String>();
result.addAll(Arrays.asList(array1));
for (String str : array2) {
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 {@code 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 ({@code null} if the passed-in
* Collection was {@code null})
*/
public static String[] toStringArray(Collection<String> collection) {
if (collection == null) {
return null;
}
return 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 ({@code null} if the passed-in
* Enumeration was {@code null})
*/
public static String[] toStringArray(Enumeration<String> enumeration) {
if (enumeration == null) {
return null;
}
List<String> list = Collections.list(enumeration);
return list.toArray(new String[list.size()]);
}
/**
* Trim the elements of the given String array,
* calling {@code 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<String> set = new TreeSet<String>();
for (String element : array) {
set.add(element);
}
return toStringArray(set);
}
/**
* Take an array Strings and split each element based on the given delimiter.
* A {@code Properties} instance is then generated, with the left of the
* delimiter providing the key, and the right of the delimiter providing the value.
* <p>Will trim both the key and value before adding them to the
* {@code Properties} instance.
* @param array the array to process
* @param delimiter to split each element using (typically the equals symbol)
* @return a {@code Properties} instance representing the array contents,
* or {@code 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 {@code Properties} instance is then generated, with the left of the
* delimiter providing the key, and the right of the delimiter providing the value.
* <p>Will trim both the key and value before adding them to the
* {@code 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 {@code null} if no removal should occur
* @return a {@code Properties} instance representing the array contents,
* or {@code null} if the array to process was {@code null} or empty
*/
public static Properties splitArrayElementsIntoProperties(
String[] array, String delimiter, String charsToDelete) {
if (ObjectUtils.isEmpty(array)) {
return null;
}
Properties result = new Properties();
for (String element : array) {
if (charsToDelete != null) {
element = deleteAny(element, 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.
* <p>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 {@code 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 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.
* <p>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 {@code 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 {@code 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 ({@code null} if the input String
* was {@code null})
* @see java.util.StringTokenizer
* @see 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<String> tokens = new ArrayList<String>();
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.
* <p>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 {@code 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.
* <p>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 {@code 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<String> result = new ArrayList<String>();
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;
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<String> commaDelimitedListToSet(String str) {
Set<String> set = new TreeSet<String>();
String[] tokens = commaDelimitedListToStringArray(str);
for (String token : tokens) {
set.add(token);
}
return set;
}
/**
* Convenience method to return a String array as a delimited (e.g. CSV)
* String. E.g. useful for {@code 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 "";
}
if (arr.length == 1) {
return ObjectUtils.nullSafeToString(arr[0]);
}
StringBuilder sb = new StringBuilder();
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 {@code toString()} implementations.
* @param arr the array to display
* @return the delimited String
*/
public static String arrayToCommaDelimitedString(Object[] arr) {
return arrayToDelimitedString(arr, ",");
}
}