Operations on CharSets.
This class handles null input gracefully.
* An exception will not be thrown for a null input.
* Each method documents its behaviour in more detail.
CharSetUtils instances should NOT be constructed in standard programming.
* Instead, the class should be used as CharSetUtils.evaluateSet(null);.
This constructor is public to permit tools that require a JavaBean instance * to operate.
*/ public CharSetUtils() { } // Factory //----------------------------------------------------------------------- /** *Creates a CharSet instance which allows a certain amount of
* set logic to be performed.
The syntax is:
*
* CharSetUtils.evaluateSet(null) = null
* CharSetUtils.evaluateSet([]) = CharSet matching nothing
* CharSetUtils.evaluateSet(["a-e"]) = CharSet matching a,b,c,d,e
*
*
* @param set the set, may be null
* @return a CharSet instance, null if null input
* @deprecated Use {@link CharSet#getInstance(String)}.
* Method will be removed in Commons Lang 3.0.
*/
public static CharSet evaluateSet(String[] set) {
if (set == null) {
return null;
}
return new CharSet(set);
}
// Squeeze
//-----------------------------------------------------------------------
/**
* Squeezes any repititions of a character that is mentioned in the * supplied set.
* *
* CharSetUtils.squeeze(null, *) = null
* CharSetUtils.squeeze("", *) = ""
* CharSetUtils.squeeze(*, null) = *
* CharSetUtils.squeeze(*, "") = *
* CharSetUtils.squeeze("hello", "k-p") = "helo"
* CharSetUtils.squeeze("hello", "a-e") = "hello"
*
*
* @see #evaluateSet(java.lang.String[]) for set-syntax.
* @param str the string to squeeze, may be null
* @param set the character set to use for manipulation, may be null
* @return modified String, null if null string input
*/
public static String squeeze(String str, String set) {
if (str == null || str.length() == 0 || set == null || set.length() == 0) {
return str;
}
String[] strs = new String[1];
strs[0] = set;
return squeeze(str, strs);
}
/**
* Squeezes any repititions of a character that is mentioned in the * supplied set.
* *An example is:
*null if null string input
*/
public static String squeeze(String str, String[] set) {
if (str == null || str.length() == 0 || set == null || set.length == 0) {
return str;
}
CharSet chars = evaluateSet(set);
StringBuffer buffer = new StringBuffer(str.length());
char[] chrs = str.toCharArray();
int sz = chrs.length;
char lastChar = ' ';
char ch = ' ';
for (int i = 0; i < sz; i++) {
ch = chrs[i];
if (chars.contains(ch)) {
if ((ch == lastChar) && (i != 0)) {
continue;
}
}
buffer.append(ch);
lastChar = ch;
}
return buffer.toString();
}
// Count
//-----------------------------------------------------------------------
/**
* Takes an argument in set-syntax, see evaluateSet, * and returns the number of characters present in the specified string.
* *
* CharSetUtils.count(null, *) = 0
* CharSetUtils.count("", *) = 0
* CharSetUtils.count(*, null) = 0
* CharSetUtils.count(*, "") = 0
* CharSetUtils.count("hello", "k-p") = 3
* CharSetUtils.count("hello", "a-e") = 1
*
*
* @see #evaluateSet(java.lang.String[]) for set-syntax.
* @param str String to count characters in, may be null
* @param set String set of characters to count, may be null
* @return character count, zero if null string input
*/
public static int count(String str, String set) {
if (str == null || str.length() == 0 || set == null || set.length() == 0) {
return 0;
}
String[] strs = new String[1];
strs[0] = set;
return count(str, strs);
}
/**
* Takes an argument in set-syntax, see evaluateSet, * and returns the number of characters present in the specified string.
* *An example would be:
*
* CharSetUtils.keep(null, *) = null
* CharSetUtils.keep("", *) = ""
* CharSetUtils.keep(*, null) = ""
* CharSetUtils.keep(*, "") = ""
* CharSetUtils.keep("hello", "hl") = "hll"
* CharSetUtils.keep("hello", "le") = "ell"
*
*
* @see #evaluateSet(java.lang.String[]) for set-syntax.
* @param str String to keep characters from, may be null
* @param set String set of characters to keep, may be null
* @return modified String, null if null string input
* @since 2.0
*/
public static String keep(String str, String set) {
if (str == null) {
return null;
}
if (str.length() == 0 || set == null || set.length() == 0) {
return "";
}
String[] strs = new String[1];
strs[0] = set;
return keep(str, strs);
}
/**
* Takes an argument in set-syntax, see evaluateSet, * and keeps any of characters present in the specified string.
* *An example would be:
*null if null string input
* @since 2.0
*/
public static String keep(String str, String[] set) {
if (str == null) {
return null;
}
if (str.length() == 0 || set == null || set.length == 0) {
return "";
}
return modify(str, set, true);
}
// Delete
//-----------------------------------------------------------------------
/**
* Takes an argument in set-syntax, see evaluateSet, * and deletes any of characters present in the specified string.
* *
* CharSetUtils.delete(null, *) = null
* CharSetUtils.delete("", *) = ""
* CharSetUtils.delete(*, null) = *
* CharSetUtils.delete(*, "") = *
* CharSetUtils.delete("hello", "hl") = "hll"
* CharSetUtils.delete("hello", "le") = "ell"
*
*
* @see #evaluateSet(java.lang.String[]) for set-syntax.
* @param str String to delete characters from, may be null
* @param set String set of characters to delete, may be null
* @return modified String, null if null string input
*/
public static String delete(String str, String set) {
if (str == null || str.length() == 0 || set == null || set.length() == 0) {
return str;
}
String[] strs = new String[1];
strs[0] = set;
return delete(str, strs);
}
/**
* Takes an argument in set-syntax, see evaluateSet, * and deletes any of characters present in the specified string.
* *An example would be:
*null if null string input
*/
public static String delete(String str, String[] set) {
if (str == null || str.length() == 0 || set == null || set.length == 0) {
return str;
}
return modify(str, set, false);
}
//-----------------------------------------------------------------------
// Implementation of delete and keep
private static String modify(String str, String[] set, boolean expect) {
CharSet chars = evaluateSet(set);
StringBuffer buffer = new StringBuffer(str.length());
char[] chrs = str.toCharArray();
int sz = chrs.length;
for(int i=0; iAn example is:
*If the length of characters to search for is greater than the * length of characters to replace, then the last character is * used.
* *
* CharSetUtils.translate(null, *, *) = null
* CharSetUtils.translate("", *, *) = ""
*
*
* @param str String to replace characters in, may be null
* @param searchChars a set of characters to search for, must not be null
* @param replaceChars a set of characters to replace, must not be null or empty ("")
* @return translated String, null if null string input
* @throws NullPointerException if with or repl
* is null
* @throws ArrayIndexOutOfBoundsException if with is empty ("")
* @deprecated Use {@link StringUtils#replaceChars(String, String, String)}.
* Method will be removed in Commons Lang 3.0.
*/
public static String translate(String str, String searchChars, String replaceChars) {
if (str == null || str.length() == 0) {
return str;
}
StringBuffer buffer = new StringBuffer(str.length());
char[] chrs = str.toCharArray();
char[] withChrs = replaceChars.toCharArray();
int sz = chrs.length;
int withMax = replaceChars.length() - 1;
for(int i=0; i