/*
* Copyright 2002-2004 The Apache Software Foundation.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.lang;
import org.apache.commons.lang.math.NumberUtils;
/**
* <p>Operations on boolean primitives and Boolean objects.</p>
*
* <p>This class tries to handle <code>null</code> input gracefully.
* An exception will not be thrown for a <code>null</code> input.
* Each method documents its behaviour in more detail.</p>
*
* @author Stephen Colebourne
* @author Matthew Hawthorne
* @author Gary Gregory
* @since 2.0
* @version $Id: BooleanUtils.java,v 1.18 2004/02/18 22:59:50 ggregory Exp $
*/
public class BooleanUtils {
/**
* <p><code>BooleanUtils</code> instances should NOT be constructed in standard programming.
* Instead, the class should be used as <code>BooleanUtils.toBooleanObject(true);</code>.</p>
*
* <p>This constructor is public to permit tools that require a JavaBean instance
* to operate.</p>
*/
public BooleanUtils() {
}
// Boolean utilities
//--------------------------------------------------------------------------
/**
* <p>Negates the specified boolean.</p>
*
* <p>If <code>null</code> is passed in, <code>null</code> will be returned.</p>
*
* <pre>
* BooleanUtils.negate(Boolean.TRUE) = Boolean.FALSE;
* BooleanUtils.negate(Boolean.FALSE) = Boolean.TRUE;
* BooleanUtils.negate(null) = null;
* </pre>
*
* @param bool the Boolean to negate, may be null
* @return the negated Boolean, or <code>null</code> if <code>null</code> input
*/
public static Boolean negate(Boolean bool) {
if (bool == null) {
return null;
}
return (bool.booleanValue() ? Boolean.FALSE : Boolean.TRUE);
}
// boolean Boolean methods
//-----------------------------------------------------------------------
/**
* <p>Boolean factory that avoids creating new Boolean objecs all the time.</p>
*
* <p>This method was added to JDK1.4 but is available here for earlier JDKs.</p>
*
* <pre>
* BooleanUtils.toBooleanObject(false) = Boolean.FALSE
* BooleanUtils.toBooleanObject(true) = Boolean.TRUE
* </pre>
*
* @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);
}
/**
* <p>Converts a Boolean to a boolean handling <code>null</code>
* by returning <code>false</code>.</p>
*
* <pre>
* BooleanUtils.toBoolean(Boolean.TRUE) = true
* BooleanUtils.toBoolean(Boolean.FALSE) = false
* BooleanUtils.toBoolean(null) = false
* </pre>
*
* @param bool the boolean to convert
* @return <code>true</code> or <code>false</code>,
* <code>null</code> returns <code>false</code>
*/
public static boolean toBoolean(Boolean bool) {
if (bool == null) {
return false;
}
return (bool.booleanValue() ? true : false);
}
/**
* <p>Converts a Boolean to a boolean handling <code>null</code>.</p>
*
* <pre>
* BooleanUtils.toBooleanDefaultIfNull(Boolean.TRUE, false) = true
* BooleanUtils.toBooleanDefaultIfNull(Boolean.FALSE, true) = false
* BooleanUtils.toBooleanDefaultIfNull(null, true) = true
* </pre>
*
* @param bool the boolean to convert
* @param valueIfNull the boolean value to return if <code>null</code>
* @return <code>true</code> or <code>false</code>
*/
public static boolean toBooleanDefaultIfNull(Boolean bool, boolean valueIfNull) {
if (bool == null) {
return valueIfNull;
}
return (bool.booleanValue() ? true : false);
}
// Integer to Boolean methods
//-----------------------------------------------------------------------
/**
* <p>Converts an int to a boolean using the convention that <code>zero</code>
* is <code>false</code>.</p>
*
* <pre>
* BooleanUtils.toBoolean(0) = false
* BooleanUtils.toBoolean(1) = true
* BooleanUtils.toBoolean(2) = true
* </pre>
*
* @param value the int to convert
* @return <code>true</code> if non-zero, <code>false</code>
* if zero
*/
public static boolean toBoolean(int value) {
return (value == 0 ? false : true);
}
/**
* <p>Converts an int to a Boolean using the convention that <code>zero</code>
* is <code>false</code>.</p>
*
* <pre>
* BooleanUtils.toBoolean(0) = Boolean.FALSE
* BooleanUtils.toBoolean(1) = Boolean.TRUE
* BooleanUtils.toBoolean(2) = Boolean.TRUE
* </pre>
*
* @param value the int to convert
* @return Boolean.TRUE if non-zero, Boolean.FALSE if zero,
* <code>null</code> if <code>null</code>
*/
public static Boolean toBooleanObject(int value) {
return (value == 0 ? Boolean.FALSE : Boolean.TRUE);
}
/**
* <p>Converts an Integer to a Boolean using the convention that <code>zero</code>
* is <code>false</code>.</p>
*
* <p><code>null</code> will be converted to <code>null</code>.</p>
*
* <pre>
* BooleanUtils.toBoolean(new Integer(0)) = Boolean.FALSE
* BooleanUtils.toBoolean(new Integer(1)) = Boolean.TRUE
* BooleanUtils.toBoolean(new Integer(null)) = null
* </pre>
*
* @param value the Integer to convert
* @return Boolean.TRUE if non-zero, Boolean.FALSE if zero,
* <code>null</code> if <code>null</code> input
*/
public static Boolean toBooleanObject(Integer value) {
if (value == null) {
return null;
}
return (value.intValue() == 0 ? Boolean.FALSE : Boolean.TRUE);
}
/**
* <p>Converts an int to a boolean specifying the conversion values.</p>
*
* <pre>
* BooleanUtils.toBoolean(0, 1, 0) = false
* BooleanUtils.toBoolean(1, 1, 0) = true
* BooleanUtils.toBoolean(2, 1, 2) = false
* BooleanUtils.toBoolean(2, 2, 0) = true
* </pre>
*
* @param value the Integer to convert
* @param trueValue the value to match for <code>true</code>
* @param falseValue the value to match for <code>false</code>
* @return <code>true</code> or <code>false</code>
* @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");
}
/**
* <p>Converts an Integer to a boolean specifying the conversion values.</p>
*
* <pre>
* BooleanUtils.toBoolean(new Integer(0), new Integer(1), new Integer(0)) = false
* BooleanUtils.toBoolean(new Integer(1), new Integer(1), new Integer(0)) = true
* BooleanUtils.toBoolean(new Integer(2), new Integer(1), new Integer(2)) = false
* BooleanUtils.toBoolean(new Integer(2), new Integer(2), new Integer(0)) = true
* BooleanUtils.toBoolean(null, null, new Integer(0)) = true
* </pre>
*
* @param value the Integer to convert
* @param trueValue the value to match for <code>true</code>,
* may be <code>null</code>
* @param falseValue the value to match for <code>false</code>,
* may be <code>null</code>
* @return <code>true</code> or <code>false</code>
* @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");
}
/**
* <p>Converts an int to a Boolean specifying the conversion values.</p>
*
* <pre>
* BooleanUtils.toBooleanObject(0, 0, 2, 3) = Boolean.TRUE
* BooleanUtils.toBooleanObject(2, 1, 2, 3) = Boolean.FALSE
* BooleanUtils.toBooleanObject(3, 1, 2, 3) = null
* </pre>
*
* @param value the Integer to convert
* @param trueValue the value to match for <code>true</code>
* @param falseValue the value to match for <code>false</code>
* @param nullValue the value to to match for <code>null</code>
* @return Boolean.TRUE, Boolean.FALSE, or <code>null</code>
* @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");
}
/**
* <p>Converts an Integer to a Boolean specifying the conversion values.</p>
*
* <pre>
* BooleanUtils.toBooleanObject(new Integer(0), new Integer(0), new Integer(2), new Integer(3)) = Boolean.TRUE
* BooleanUtils.toBooleanObject(new Integer(2), new Integer(1), new Integer(2), new Integer(3)) = Boolean.FALSE
* BooleanUtils.toBooleanObject(new Integer(3), new Integer(1), new Integer(2), new Integer(3)) = null
* </pre>
*
* @param value the Integer to convert
* @param trueValue the value to match for <code>true</code>,
* may be <code>null</code>
* @param falseValue the value to match for <code>false</code>,
* may be <code>null</code>
* @param nullValue the value to to match for <code>null</code>,
* may be <code>null</code>
* @return Boolean.TRUE, Boolean.FALSE, or <code>null</code>
* @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
//-----------------------------------------------------------------------
/**
* <p>Converts a boolean to an int using the convention that
* <code>zero</code> is <code>false</code>.</p>
*
* <pre>
* BooleanUtils.toInteger(true) = 1
* BooleanUtils.toInteger(false) = 0
* </pre>
*
* @param bool the boolean to convert
* @return one if <code>true</code>, zero if <code>false</code>
*/
public static int toInteger(boolean bool) {
return (bool ? 1 : 0);
}
/**
* <p>Converts a boolean to an Integer using the convention that
* <code>zero</code> is <code>false</code>.</p>
*
* <pre>
* BooleanUtils.toIntegerObject(true) = new Integer(1)
* BooleanUtils.toIntegerObject(false) = new Integer(0)
* </pre>
*
* @param bool the boolean to convert
* @return one if <code>true</code>, zero if <code>false</code>
*/
public static Integer toIntegerObject(boolean bool) {
return (bool ? NumberUtils.INTEGER_ONE : NumberUtils.INTEGER_ZERO);
}
/**
* <p>Converts a Boolean to a Integer using the convention that
* <code>zero</code> is <code>false</code>.</p>
*
* <p><code>null</code> will be converted to <code>null</code>.</p>
*
* <pre>
* BooleanUtils.toIntegerObject(Boolean.TRUE) = new Integer(1)
* BooleanUtils.toIntegerObject(Boolean.FALSE) = new Integer(0)
* </pre>
*
* @param bool the Boolean to convert
* @return one if Boolean.TRUE, zero if Boolean.FALSE, <code>null</code> if <code>null</code>
*/
public static Integer toIntegerObject(Boolean bool) {
if (bool == null) {
return null;
}
return (bool.booleanValue() ? NumberUtils.INTEGER_ONE : NumberUtils.INTEGER_ZERO);
}
/**
* <p>Converts a boolean to an int specifying the conversion values.</p>
*
* <pre>
* BooleanUtils.toInteger(true, 1, 0) = 1
* BooleanUtils.toInteger(false, 1, 0) = 0
* </pre>
*
* @param bool the to convert
* @param trueValue the value to return if <code>true</code>
* @param falseValue the value to return if <code>false</code>
* @return the appropriate value
*/
public static int toInteger(boolean bool, int trueValue, int falseValue) {
return (bool ? trueValue : falseValue);
}
/**
* <p>Converts a Boolean to an int specifying the conversion values.</p>
*
* <pre>
* BooleanUtils.toInteger(Boolean.TRUE, 1, 0, 2) = 1
* BooleanUtils.toInteger(Boolean.FALSE, 1, 0, 2) = 0
* BooleanUtils.toInteger(null, 1, 0, 2) = 2
* </pre>
*
* @param bool the Boolean to convert
* @param trueValue the value to return if <code>true</code>
* @param falseValue the value to return if <code>false</code>
* @param nullValue the value to return if <code>null</code>
* @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);
}
/**
* <p>Converts a boolean to an Integer specifying the conversion values.</p>
*
* <pre>
* BooleanUtils.toIntegerObject(true, new Integer(1), new Integer(0)) = new Integer(1)
* BooleanUtils.toIntegerObject(false, new Integer(1), new Integer(0)) = new Integer(0)
* </pre>
*
* @param bool the to convert
* @param trueValue the value to return if <code>true</code>,
* may be <code>null</code>
* @param falseValue the value to return if <code>false</code>,
* may be <code>null</code>
* @return the appropriate value
*/
public static Integer toIntegerObject(boolean bool, Integer trueValue, Integer falseValue) {
return (bool ? trueValue : falseValue);
}
/**
* <p>Converts a Boolean to an Integer specifying the conversion values.</p>
*
* <pre>
* BooleanUtils.toIntegerObject(Boolean.TRUE, new Integer(1), new Integer(0), new Integer(2)) = new Integer(1)
* BooleanUtils.toIntegerObject(Boolean.FALSE, new Integer(1), new Integer(0), new Integer(2)) = new Integer(0)
* BooleanUtils.toIntegerObject(null, new Integer(1), new Integer(0), new Integer(2)) = new Integer(2)
* </pre>
*
* @param bool the Boolean to convert
* @param trueValue the value to return if <code>true</code>,
* may be <code>null</code>
* @param falseValue the value to return if <code>false</code>,
* may be <code>null</code>
* @param nullValue the value to return if <code>null</code>,
* may be <code>null</code>
* @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
//-----------------------------------------------------------------------
/**
* <p>Converts a String to a Boolean.</p>
*
* <p><code>'true'</code>, <code>'on'</code> or <code>'yes'</code>
* (case insensitive) will return <code>true</code>.
* <code>'false'</code>, <code>'off'</code> or <code>'no'</code>
* (case insensitive) will return <code>false</code>.
* Otherwise, <code>null</code> is returned.</p>
*
* <pre>
* BooleanUtils.toBooleanObject(null) = null
* BooleanUtils.toBooleanObject("true") = Boolean.TRUE
* BooleanUtils.toBooleanObject("false") = Boolean.FALSE
* BooleanUtils.toBooleanObject("on") = Boolean.TRUE
* BooleanUtils.toBooleanObject("ON") = Boolean.TRUE
* BooleanUtils.toBooleanObject("off") = Boolean.FALSE
* BooleanUtils.toBooleanObject("oFf") = Boolean.FALSE
* BooleanUtils.toBooleanObject("blue") = null
* </pre>
*
* @param str the String to check
* @return the Boolean value of the string,
* <code>null</code> if no match or <code>null</code> 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;
}
/**
* <p>Converts a String to a Boolean throwing an exception if no match.</p>
*
* <pre>
* BooleanUtils.toBooleanObject("true", "true", "false", "null") = Boolean.TRUE
* BooleanUtils.toBooleanObject("false", "true", "false", "null") = Boolean.FALSE
* BooleanUtils.toBooleanObject("null", "true", "false", "null") = null
* </pre>
*
* @param str the String to check
* @param trueString the String to match for <code>true</code>
* (case sensitive), may be <code>null</code>
* @param falseString the String to match for <code>false</code>
* (case sensitive), may be <code>null</code>
* @param nullString the String to match for <code>null</code>
* (case sensitive), may be <code>null</code>
* @return the Boolean value of the string,
* <code>null</code> if no match or <code>null</code> 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
//-----------------------------------------------------------------------
/**
* <p>Converts a String to a boolean (optimised for performance).</p>
*
* <p><code>'true'</code>, <code>'on'</code> or <code>'yes'</code>
* (case insensitive) will return <code>true</code>. Otherwise,
* <code>false</code> is returned.</p>
*
* <p>This method performs 4 times faster (JDK1.4) than
* <code>Boolean.valueOf(String)</code>. However, this method accepts
* 'on' and 'yes' as true values.
*
* <pre>
* BooleanUtils.toBoolean(null) = false
* BooleanUtils.toBoolean("true") = true
* BooleanUtils.toBoolean("TRUE") = true
* BooleanUtils.toBoolean("tRUe") = true
* BooleanUtils.toBoolean("on") = true
* BooleanUtils.toBoolean("yes") = true
* BooleanUtils.toBoolean("false") = false
* BooleanUtils.toBoolean("x gti") = false
* </pre>
*
* @param str the String to check
* @return the boolean value of the string, <code>false</code> if no match
*/
public static boolean toBoolean(String str) {
// Previously used equalsIgnoreCase, which was fast for interned 'true'.
// Non interned 'true' matched 15 times slower.
//
// Optimisation provides same performance as before for interned 'true'.
// Similar performance for null, 'false', and other strings not length 2/3/4.
// 'true'/'TRUE' match 4 times slower, 'tRUE'/'True' 7 times slower.
if (str == "true") {
return true;
}
if (str == null) {
return false;
}
switch (str.length()) {
case 2: {
char ch0 = str.charAt(0);
char ch1 = str.charAt(1);
return
(ch0 == 'o' || ch0 == 'O') &&
(ch1 == 'n' || ch1 == 'N');
}
case 3: {
char ch = str.charAt(0);
if (ch == 'y') {
return
(str.charAt(1) == 'e' || str.charAt(1) == 'E') &&
(str.charAt(2) == 's' || str.charAt(2) == 'S');
}
if (ch == 'Y') {
return
(str.charAt(1) == 'E' || str.charAt(1) == 'e') &&
(str.charAt(2) == 'S' || str.charAt(2) == 's');
}
}
case 4: {
char ch = str.charAt(0);
if (ch == 't') {
return
(str.charAt(1) == 'r' || str.charAt(1) == 'R') &&
(str.charAt(2) == 'u' || str.charAt(2) == 'U') &&
(str.charAt(3) == 'e' || str.charAt(3) == 'E');
}
if (ch == 'T') {
return
(str.charAt(1) == 'R' || str.charAt(1) == 'r') &&
(str.charAt(2) == 'U' || str.charAt(2) == 'u') &&
(str.charAt(3) == 'E' || str.charAt(3) == 'e');
}
}
}
return false;
}
// public static void main(String[] args) {
// long start = System.currentTimeMillis();
// boolean flag = true;
// int count = 0;
// for (int i = 0; i < 100000000; i++) {
// flag = toBoolean("YES");
// }
// long end = System.currentTimeMillis();
// System.out.println((end - start) + " " + flag + " " + count);
// }
/**
* <p>Converts a String to a Boolean throwing an exception if no match found.</p>
*
* <p>null is returned if there is no match.</p>
*
* <pre>
* BooleanUtils.toBoolean("true", "true", "false") = true
* BooleanUtils.toBoolean("false", "true", "false") = false
* </pre>
*
* @param str the String to check
* @param trueString the String to match for <code>true</code>
* (case sensitive), may be <code>null</code>
* @param falseString the String to match for <code>false</code>
* (case sensitive), may be <code>null</code>
* @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
//-----------------------------------------------------------------------
/**
* <p>Converts a Boolean to a String returning <code>'true'</code>,
* <code>'false'</code>, or <code>null</code>.</p>
*
* <pre>
* BooleanUtils.toStringTrueFalse(Boolean.TRUE) = "true"
* BooleanUtils.toStringTrueFalse(Boolean.FALSE) = "false"
* BooleanUtils.toStringTrueFalse(null) = null;
* </pre>
*
* @param bool the Boolean to check
* @return <code>'true'</code>, <code>'false'</code>,
* or <code>null</code>
*/
public static String toStringTrueFalse(Boolean bool) {
return toString(bool, "true", "false", null);
}
/**
* <p>Converts a Boolean to a String returning <code>'on'</code>,
* <code>'off'</code>, or <code>null</code>.</p>
*
* <pre>
* BooleanUtils.toStringOnOff(Boolean.TRUE) = "on"
* BooleanUtils.toStringOnOff(Boolean.FALSE) = "off"
* BooleanUtils.toStringOnOff(null) = null;
* </pre>
*
* @param bool the Boolean to check
* @return <code>'on'</code>, <code>'off'</code>,
* or <code>null</code>
*/
public static String toStringOnOff(Boolean bool) {
return toString(bool, "on", "off", null);
}
/**
* <p>Converts a Boolean to a String returning <code>'yes'</code>,
* <code>'no'</code>, or <code>null</code>.</p>
*
* <pre>
* BooleanUtils.toStringYesNo(Boolean.TRUE) = "yes"
* BooleanUtils.toStringYesNo(Boolean.FALSE) = "no"
* BooleanUtils.toStringYesNo(null) = null;
* </pre>
*
* @param bool the Boolean to check
* @return <code>'yes'</code>, <code>'no'</code>,
* or <code>null</code>
*/
public static String toStringYesNo(Boolean bool) {
return toString(bool, "yes", "no", null);
}
/**
* <p>Converts a Boolean to a String returning one of the input Strings.</p>
*
* <pre>
* BooleanUtils.toString(Boolean.TRUE, "true", "false", null) = "true"
* BooleanUtils.toString(Boolean.FALSE, "true", "false", null) = "false"
* BooleanUtils.toString(null, "true", "false", null) = null;
* </pre>
*
* @param bool the Boolean to check
* @param trueString the String to return if <code>true</code>,
* may be <code>null</code>
* @param falseString the String to return if <code>false</code>,
* may be <code>null</code>
* @param nullString the String to return if <code>null</code>,
* may be <code>null</code>
* @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
//-----------------------------------------------------------------------
/**
* <p>Converts a boolean to a String returning <code>'true'</code>
* or <code>'false'</code>.</p>
*
* <pre>
* BooleanUtils.toStringTrueFalse(true) = "true"
* BooleanUtils.toStringTrueFalse(false) = "false"
* </pre>
*
* @param bool the Boolean to check
* @return <code>'true'</code>, <code>'false'</code>,
* or <code>null</code>
*/
public static String toStringTrueFalse(boolean bool) {
return toString(bool, "true", "false");
}
/**
* <p>Converts a boolean to a String returning <code>'on'</code>
* or <code>'off'</code>.</p>
*
* <pre>
* BooleanUtils.toStringOnOff(true) = "on"
* BooleanUtils.toStringOnOff(false) = "off"
* </pre>
*
* @param bool the Boolean to check
* @return <code>'on'</code>, <code>'off'</code>,
* or <code>null</code>
*/
public static String toStringOnOff(boolean bool) {
return toString(bool, "on", "off");
}
/**
* <p>Converts a boolean to a String returning <code>'yes'</code>
* or <code>'no'</code>.</p>
*
* <pre>
* BooleanUtils.toStringYesNo(true) = "yes"
* BooleanUtils.toStringYesNo(false) = "no"
* </pre>
*
* @param bool the Boolean to check
* @return <code>'yes'</code>, <code>'no'</code>,
* or <code>null</code>
*/
public static String toStringYesNo(boolean bool) {
return toString(bool, "yes", "no");
}
/**
* <p>Converts a boolean to a String returning one of the input Strings.</p>
*
* <pre>
* BooleanUtils.toString(true, "true", "false") = "true"
* BooleanUtils.toString(false, "true", "false") = "false"
* </pre>
*
* @param bool the Boolean to check
* @param trueString the String to return if <code>true</code>,
* may be <code>null</code>
* @param falseString the String to return if <code>false</code>,
* may be <code>null</code>
* @return one of the two input Strings
*/
public static String toString(boolean bool, String trueString, String falseString) {
return (bool ? trueString : falseString);
}
// xor methods
// ----------------------------------------------------------------------
/**
* <p>Performs an xor on a set of booleans.</p>
*
* <pre>
* BooleanUtils.xor(new boolean[] { true, true }) = false
* BooleanUtils.xor(new boolean[] { false, false }) = false
* BooleanUtils.xor(new boolean[] { true, false }) = true
* </pre>
*
* @param array an array of <code>boolean<code>s
* @return <code>true</code> if the xor is successful.
* @throws IllegalArgumentException if <code>array</code> is <code>null</code>
* @throws IllegalArgumentException if <code>array</code> 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;
}
/**
* <p>Performs an xor on an array of Booleans.</p>
*
* <pre>
* BooleanUtils.xor(new Boolean[] { Boolean.TRUE, Boolean.TRUE }) = Boolean.FALSE
* BooleanUtils.xor(new Boolean[] { Boolean.FALSE, Boolean.FALSE }) = Boolean.FALSE
* BooleanUtils.xor(new Boolean[] { Boolean.TRUE, Boolean.FALSE }) = Boolean.TRUE
* </pre>
*
* @param array an array of <code>Boolean<code>s
* @return <code>true</code> if the xor is successful.
* @throws IllegalArgumentException if <code>array</code> is <code>null</code>
* @throws IllegalArgumentException if <code>array</code> is empty.
* @throws IllegalArgumentException if <code>array</code> contains a <code>null</code>
*/
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 contain any null elements");
}
return (xor(primitive) ? Boolean.TRUE : Boolean.FALSE);
}
}
