Operations on boolean primitives and Boolean objects.
* *This class tries to handle null input gracefully.
* An exception will not be thrown for a null input.
* Each method documents its behaviour in more detail.
BooleanUtils instances should NOT be constructed in standard programming.
* Instead, the class should be used as BooleanUtils.toBooleanObject(true);.
This constructor is public to permit tools that require a JavaBean instance * to operate.
*/ public BooleanUtils() { } // Boolean utilities //-------------------------------------------------------------------------- /** *Negates the specified boolean.
* *If null is passed in, null will be returned.
null if null input
*/
public static Boolean negate(Boolean bool) {
if (bool == null) {
return null;
}
return (bool.booleanValue() ? Boolean.FALSE : Boolean.TRUE);
}
// boolean Boolean methods
//-----------------------------------------------------------------------
/**
* Boolean factory that avoids creating new Boolean objecs all the time.
* *This method was added to JDK1.4 but is available here for earlier JDKs.
* * @param bool the boolean to convert * @return Boolean.TRUE or Boolean.FALSE as appropriate */ public static Boolean toBooleanObject(boolean bool) { return (bool ? Boolean.TRUE : Boolean.FALSE); } /** *Converts a Boolean to a boolean handling null
* by returning false.
true or false,
* null returns false
*/
public static boolean toBoolean(Boolean bool) {
if (bool == null) {
return false;
}
return (bool.booleanValue() ? true : false);
}
/**
* Converts a Boolean to a boolean handling null.
null
* @return true or false
*/
public static boolean toBooleanDefaultIfNull(Boolean bool, boolean valueIfNull) {
if (bool == null) {
return valueIfNull;
}
return (bool.booleanValue() ? true : false);
}
// Integer to Boolean methods
//-----------------------------------------------------------------------
/**
* Converts an int to a boolean using the convention that zero
* is false.
true if non-zero, false
* if zero
*/
public static boolean toBoolean(int value) {
return (value == 0 ? false : true);
}
/**
* Converts an int to a Boolean using the convention that zero
* is false.
null if null
*/
public static Boolean toBooleanObject(int value) {
return (value == 0 ? Boolean.FALSE : Boolean.TRUE);
}
/**
* Converts an Integer to a Boolean using the convention that zero
* is false.
null will be converted to null.
null if null input
*/
public static Boolean toBooleanObject(Integer value) {
if (value == null) {
return null;
}
return (value.intValue() == 0 ? Boolean.FALSE : Boolean.TRUE);
}
/**
* Converts an int to a boolean specifying the conversion values.
* * @param value the Integer to convert * @param trueValue the value to match fortrue
* @param falseValue the value to match for false
* @return true or false
* @throws IllegalArgumentException if no match
*/
public static boolean toBoolean(int value, int trueValue, int falseValue) {
if (value == trueValue) {
return true;
} else if (value == falseValue) {
return false;
}
// no match
throw new IllegalArgumentException("The Integer did not match either specified value");
}
/**
* Converts an Integer to a boolean specifying the conversion values.
* * @param value the Integer to convert * @param trueValue the value to match fortrue,
* may be null
* @param falseValue the value to match for false,
* may be null
* @return true or false
* @throws IllegalArgumentException if no match
*/
public static boolean toBoolean(Integer value, Integer trueValue, Integer falseValue) {
if (value == null) {
if (trueValue == null) {
return true;
} else if (falseValue == null) {
return false;
}
} else if (value.equals(trueValue)) {
return true;
} else if (value.equals(falseValue)) {
return false;
}
// no match
throw new IllegalArgumentException("The Integer did not match either specified value");
}
/**
* Converts an int to a Boolean specifying the conversion values.
* * @param value the Integer to convert * @param trueValue the value to match fortrue
* @param falseValue the value to match for false
* @param nullValue the value to to match for null
* @return Boolean.TRUE, Boolean.FALSE, or null
* @throws IllegalArgumentException if no match
*/
public static Boolean toBooleanObject(int value, int trueValue, int falseValue, int nullValue) {
if (value == trueValue) {
return Boolean.TRUE;
} else if (value == falseValue) {
return Boolean.FALSE;
} else if (value == nullValue) {
return null;
}
// no match
throw new IllegalArgumentException("The Integer did not match any specified value");
}
/**
* Converts an Integer to a Boolean specifying the conversion values.
* * @param value the Integer to convert * @param trueValue the value to match fortrue,
* may be null
* @param falseValue the value to match for false,
* may be null
* @param nullValue the value to to match for null,
* may be null
* @return Boolean.TRUE, Boolean.FALSE, or null
* @throws IllegalArgumentException if no match
*/
public static Boolean toBooleanObject(Integer value, Integer trueValue, Integer falseValue, Integer nullValue) {
if (value == null) {
if (trueValue == null) {
return Boolean.TRUE;
} else if (falseValue == null) {
return Boolean.FALSE;
} else if (nullValue == null) {
return null;
}
} else if (value.equals(trueValue)) {
return Boolean.TRUE;
} else if (value.equals(falseValue)) {
return Boolean.FALSE;
} else if (value.equals(nullValue)) {
return null;
}
// no match
throw new IllegalArgumentException("The Integer did not match any specified value");
}
// Boolean to Integer methods
//-----------------------------------------------------------------------
/**
* Converts a boolean to an int using the convention that
* zero is false.
true, zero if false
*/
public static int toInteger(boolean bool) {
return (bool ? 1 : 0);
}
/**
* Converts a boolean to an Integer using the convention that
* zero is false.
true, zero if false
*/
public static Integer toIntegerObject(boolean bool) {
return (bool ? NumberUtils.INTEGER_ONE : NumberUtils.INTEGER_ZERO);
}
/**
* Converts a Boolean to a Integer using the convention that
* zero is false.
null will be converted to null.
null if null
*/
public static Integer toIntegerObject(Boolean bool) {
if (bool == null) {
return null;
}
return (bool.booleanValue() ? NumberUtils.INTEGER_ONE : NumberUtils.INTEGER_ZERO);
}
/**
* Converts a boolean to an int specifying the conversion values.
* * @param bool the to convert * @param trueValue the value to return iftrue
* @param falseValue the value to return if false
* @return the appropriate value
*/
public static int toInteger(boolean bool, int trueValue, int falseValue) {
return (bool ? trueValue : falseValue);
}
/**
* Converts a Boolean to an int specifying the conversion values.
* * @param bool the Boolean to convert * @param trueValue the value to return iftrue
* @param falseValue the value to return if false
* @param nullValue the value to return if null
* @return the appropriate value
*/
public static int toInteger(Boolean bool, int trueValue, int falseValue, int nullValue) {
if (bool == null) {
return nullValue;
}
return (bool.booleanValue() ? trueValue : falseValue);
}
/**
* Converts a boolean to an Integer specifying the conversion values.
* * @param bool the to convert * @param trueValue the value to return iftrue,
* may be null
* @param falseValue the value to return if false,
* may be null
* @return the appropriate value
*/
public static Integer toIntegerObject(boolean bool, Integer trueValue, Integer falseValue) {
return (bool ? trueValue : falseValue);
}
/**
* Converts a Boolean to an Integer specifying the conversion values.
* * @param bool the Boolean to convert * @param trueValue the value to return iftrue,
* may be null
* @param falseValue the value to return if false,
* may be null
* @param nullValue the value to return if null,
* may be null
* @return the appropriate value
*/
public static Integer toIntegerObject(Boolean bool, Integer trueValue, Integer falseValue, Integer nullValue) {
if (bool == null) {
return nullValue;
}
return (bool.booleanValue() ? trueValue : falseValue);
}
// String to Boolean methods
//-----------------------------------------------------------------------
/**
* Converts a String to a Boolean.
* *'true', 'on' or 'yes'
* (case insensitive) will return true.
* 'false', 'off' or 'no'
* (case insensitive) will return false.
* Otherwise, null is returned.
null if no match or null input
*/
public static Boolean toBooleanObject(String str) {
if ("true".equalsIgnoreCase(str)) {
return Boolean.TRUE;
} else if ("false".equalsIgnoreCase(str)) {
return Boolean.FALSE;
} else if ("on".equalsIgnoreCase(str)) {
return Boolean.TRUE;
} else if ("off".equalsIgnoreCase(str)) {
return Boolean.FALSE;
} else if ("yes".equalsIgnoreCase(str)) {
return Boolean.TRUE;
} else if ("no".equalsIgnoreCase(str)) {
return Boolean.FALSE;
}
// no match
return null;
}
/**
* Converts a String to a Boolean throwing an exception if no match.
* * @param str the String to check * @param trueString the String to match fortrue
* (case sensitive), may be null
* @param falseString the String to match for false
* (case sensitive), may be null
* @param nullString the String to match for null
* (case sensitive), may be null
* @return the Boolean value of the string,
* null if no match or null input
*/
public static Boolean toBooleanObject(String str, String trueString, String falseString, String nullString) {
if (str == null) {
if (trueString == null) {
return Boolean.TRUE;
} else if (falseString == null) {
return Boolean.FALSE;
} else if (nullString == null) {
return null;
}
} else if (str.equals(trueString)) {
return Boolean.TRUE;
} else if (str.equals(falseString)) {
return Boolean.FALSE;
} else if (str.equals(nullString)) {
return null;
}
// no match
throw new IllegalArgumentException("The String did not match any specified value");
}
// String to boolean methods
//-----------------------------------------------------------------------
/**
* Converts a String to a boolean.
* *'true', 'on' or 'yes'
* (case insensitive) will return true. Otherwise,
* false is returned.
false if no match
*/
public static boolean toBoolean(String str) {
if ("true".equalsIgnoreCase(str)) {
return true;
} else if ("on".equalsIgnoreCase(str)) {
return true;
} else if ("yes".equalsIgnoreCase(str)) {
return true;
}
// no match
return false;
}
/**
* Converts a String to a Boolean throwing an exception if no match found.
* *null is returned if there is no match.
* * @param str the String to check * @param trueString the String to match fortrue
* (case sensitive), may be null
* @param falseString the String to match for false
* (case sensitive), may be null
* @return the boolean value of the string
* @throws IllegalArgumentException if the String doesn't match
*/
public static boolean toBoolean(String str, String trueString, String falseString) {
if (str == null) {
if (trueString == null) {
return true;
} else if (falseString == null) {
return false;
}
} else if (str.equals(trueString)) {
return true;
} else if (str.equals(falseString)) {
return false;
}
// no match
throw new IllegalArgumentException("The String did not match either specified value");
}
// Boolean to String methods
//-----------------------------------------------------------------------
/**
* Converts a Boolean to a String returning 'true',
* 'false', or null.
'true', 'false',
* or null
*/
public static String toStringTrueFalse(Boolean bool) {
return toString(bool, "true", "false", null);
}
/**
* Converts a Boolean to a String returning 'on',
* 'off', or null.
'on', 'off',
* or null
*/
public static String toStringOnOff(Boolean bool) {
return toString(bool, "on", "off", null);
}
/**
* Converts a Boolean to a String returning 'yes',
* 'no', or null.
'yes', 'no',
* or null
*/
public static String toStringYesNo(Boolean bool) {
return toString(bool, "yes", "no", null);
}
/**
* Converts a Boolean to a String returning one of the input Strings.
* * @param bool the Boolean to check * @param trueString the String to return iftrue,
* may be null
* @param falseString the String to return if false,
* may be null
* @param nullString the String to return if null,
* may be null
* @return one of the three input Strings
*/
public static String toString(Boolean bool, String trueString, String falseString, String nullString) {
if (bool == null) {
return nullString;
}
return (bool.booleanValue() ? trueString : falseString);
}
// boolean to String methods
//-----------------------------------------------------------------------
/**
* Converts a boolean to a String returning 'true'
* or 'false'.
'true', 'false',
* or null
*/
public static String toStringTrueFalse(boolean bool) {
return toString(bool, "true", "false");
}
/**
* Converts a boolean to a String returning 'on'
* or 'off'.
'on', 'off',
* or null
*/
public static String toStringOnOff(boolean bool) {
return toString(bool, "on", "off");
}
/**
* Converts a boolean to a String returning 'yes'
* or 'no'.
'yes', 'no',
* or null
*/
public static String toStringYesNo(boolean bool) {
return toString(bool, "yes", "no");
}
/**
* Converts a boolean to a String returning one of the input Strings.
* * @param bool the Boolean to check * @param trueString the String to return iftrue,
* may be null
* @param falseString the String to return if false,
* may be null
* @return one of the two input Strings
*/
public static String toString(boolean bool, String trueString, String falseString) {
return (bool ? trueString : falseString);
}
// xor methods
// ----------------------------------------------------------------------
/**
* Performs an xor on a set of booleans.
* * @param array an array ofbooleans
* @return true if the xor is successful.
* @throws IllegalArgumentException if array is null
* @throws IllegalArgumentException if array is empty.
*/
public static boolean xor(boolean[] array) {
// Validates input
if (array == null) {
throw new IllegalArgumentException("The Array must not be null");
} else if (array.length == 0) {
throw new IllegalArgumentException("Array is empty");
}
// Loops through array, comparing each item
int trueCount = 0;
for (int i = 0; i < array.length; i++) {
// If item is true, and trueCount is < 1, increments count
// Else, xor fails
if (array[i]) {
if (trueCount < 1) {
trueCount++;
} else {
return false;
}
}
}
// Returns true if there was exactly 1 true item
return trueCount == 1;
}
/**
* Performs an xor on an array of Booleans.
*
* @param array an array of Booleans
* @return true if the xor is successful.
* @throws IllegalArgumentException if array is null
* @throws IllegalArgumentException if array is empty.
* @throws IllegalArgumentException if array contains a null
*/
public static Boolean xor(Boolean[] array) {
if (array == null) {
throw new IllegalArgumentException("The Array must not be null");
} else if (array.length == 0) {
throw new IllegalArgumentException("Array is empty");
}
boolean[] primitive = null;
try {
primitive = ArrayUtils.toPrimitive(array);
} catch (NullPointerException ex) {
throw new IllegalArgumentException("The array must not conatin any null elements");
}
return (xor(primitive) ? Boolean.TRUE : Boolean.FALSE);
}
}