Improve performance of BooleanUtils.toBoolean(String)
git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/lang/trunk@137686 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Stephen Colebourne
parent
25a4549ceb
commit
d776d26889
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@ -66,7 +66,7 @@ import org.apache.commons.lang.math.NumberUtils;
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* @author Matthew Hawthorne
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* @author Gary Gregory
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* @since 2.0
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* @version $Id: BooleanUtils.java,v 1.16 2003/09/23 19:45:14 fredrik Exp $
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* @version $Id: BooleanUtils.java,v 1.17 2003/10/21 23:23:06 scolebourne Exp $
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*/
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public class BooleanUtils {
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@ -502,12 +502,14 @@ public class BooleanUtils {
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* Otherwise, <code>null</code> is returned.</p>
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*
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* <pre>
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* BooleanUtils.toBooleanObject(null) = null
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* BooleanUtils.toBooleanObject("true") = Boolean.TRUE
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* BooleanUtils.toBooleanObject("false") = Boolean.FALSE
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* BooleanUtils.toBooleanObject("on") = Boolean.TRUE
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* BooleanUtils.toBooleanObject("ON") = Boolean.TRUE
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* BooleanUtils.toBooleanObject("off") = Boolean.FALSE
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* BooleanUtils.toBooleanObject("oFf") = Boolean.FALSE
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* BooleanUtils.toBooleanObject("blue") = null
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* </pre>
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*
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* @param str the String to check
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@ -574,34 +576,94 @@ public class BooleanUtils {
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// String to boolean methods
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//-----------------------------------------------------------------------
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/**
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* <p>Converts a String to a boolean.</p>
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* <p>Converts a String to a boolean (optimised for performance).</p>
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*
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* <p><code>'true'</code>, <code>'on'</code> or <code>'yes'</code>
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* (case insensitive) will return <code>true</code>. Otherwise,
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* <code>false</code> is returned.</p>
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*
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* <p>This method performs 4 times faster (JDK1.4) than
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* <code>Boolean.valueOf(String)</code>. However, this method accepts
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* 'on' and 'yes' as true values.
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*
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* <pre>
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* BooleanUtils.toBoolean(null) = false
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* BooleanUtils.toBoolean("true") = true
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* BooleanUtils.toBoolean("TRUE") = true
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* BooleanUtils.toBoolean("tRUe") = true
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* BooleanUtils.toBoolean("on") = true
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* BooleanUtils.toBoolean("yes") = true
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* BooleanUtils.toBoolean("false") = false
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* BooleanUtils.toBoolean("x gti") = false
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* </pre>
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*
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* @param str the String to check
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* @return the boolean value of the string, <code>false</code> if no match
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*/
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public static boolean toBoolean(String str) {
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if ("true".equalsIgnoreCase(str)) {
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return true;
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} else if ("on".equalsIgnoreCase(str)) {
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return true;
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} else if ("yes".equalsIgnoreCase(str)) {
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// Previously used equalsIgnoreCase, which was fast for interned 'true'.
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// Non interned 'true' matched 15 times slower.
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//
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// Optimisation provides same performance as before for interned 'true'.
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// Similar performance for null, 'false', and other strings not length 2/3/4.
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// 'true'/'TRUE' match 4 times slower, 'tRUE'/'True' 7 times slower.
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if (str == "true") {
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return true;
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}
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// no match
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if (str == null) {
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return false;
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}
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switch (str.length()) {
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case 2: {
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char ch0 = str.charAt(0);
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char ch1 = str.charAt(1);
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return
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(ch0 == 'o' || ch0 == 'O') &&
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(ch1 == 'n' || ch1 == 'N');
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}
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case 3: {
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char ch = str.charAt(0);
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if (ch == 'y') {
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return
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(str.charAt(1) == 'e' || str.charAt(1) == 'E') &&
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(str.charAt(2) == 's' || str.charAt(2) == 'S');
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}
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if (ch == 'Y') {
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return
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(str.charAt(1) == 'E' || str.charAt(1) == 'e') &&
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(str.charAt(2) == 'S' || str.charAt(2) == 's');
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}
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}
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case 4: {
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char ch = str.charAt(0);
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if (ch == 't') {
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return
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(str.charAt(1) == 'r' || str.charAt(1) == 'R') &&
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(str.charAt(2) == 'u' || str.charAt(2) == 'U') &&
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(str.charAt(3) == 'e' || str.charAt(3) == 'E');
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}
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if (ch == 'T') {
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return
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(str.charAt(1) == 'R' || str.charAt(1) == 'r') &&
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(str.charAt(2) == 'U' || str.charAt(2) == 'u') &&
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(str.charAt(3) == 'E' || str.charAt(3) == 'e');
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}
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}
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}
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return false;
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}
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// public static void main(String[] args) {
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// long start = System.currentTimeMillis();
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// boolean flag = true;
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// int count = 0;
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// for (int i = 0; i < 100000000; i++) {
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// flag = toBoolean("YES");
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// }
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// long end = System.currentTimeMillis();
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// System.out.println((end - start) + " " + flag + " " + count);
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// }
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/**
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* <p>Converts a String to a Boolean throwing an exception if no match found.</p>
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*
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@ -66,7 +66,7 @@ import junit.textui.TestRunner;
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*
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* @author Stephen Colebourne
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* @author Matthew Hawthorne
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* @version $Id: BooleanUtilsTest.java,v 1.7 2003/08/18 02:22:25 bayard Exp $
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* @version $Id: BooleanUtilsTest.java,v 1.8 2003/10/21 23:23:06 scolebourne Exp $
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*/
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public class BooleanUtilsTest extends TestCase {
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@ -308,13 +308,39 @@ public class BooleanUtilsTest extends TestCase {
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assertEquals(false, BooleanUtils.toBoolean(""));
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assertEquals(false, BooleanUtils.toBoolean("off"));
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assertEquals(false, BooleanUtils.toBoolean("oof"));
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assertEquals(true, BooleanUtils.toBoolean("true"));
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assertEquals(true, BooleanUtils.toBoolean("yes"));
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assertEquals(true, BooleanUtils.toBoolean("on"));
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assertEquals(false, BooleanUtils.toBoolean("yep"));
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assertEquals(false, BooleanUtils.toBoolean("trux"));
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assertEquals(false, BooleanUtils.toBoolean("false"));
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assertEquals(false, BooleanUtils.toBoolean("a"));
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assertEquals(true, BooleanUtils.toBoolean("true")); // interned handled differently
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assertEquals(true, BooleanUtils.toBoolean(new StringBuffer("tr").append("ue").toString()));
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assertEquals(true, BooleanUtils.toBoolean("truE"));
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assertEquals(true, BooleanUtils.toBoolean("trUe"));
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assertEquals(true, BooleanUtils.toBoolean("trUE"));
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assertEquals(true, BooleanUtils.toBoolean("tRue"));
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assertEquals(true, BooleanUtils.toBoolean("tRuE"));
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assertEquals(true, BooleanUtils.toBoolean("tRUe"));
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assertEquals(true, BooleanUtils.toBoolean("tRUE"));
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assertEquals(true, BooleanUtils.toBoolean("TRUE"));
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assertEquals(true, BooleanUtils.toBoolean("ON"));
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assertEquals(true, BooleanUtils.toBoolean("YES"));
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assertEquals(true, BooleanUtils.toBoolean("TRUe"));
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assertEquals(true, BooleanUtils.toBoolean("TRuE"));
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assertEquals(true, BooleanUtils.toBoolean("TRue"));
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assertEquals(true, BooleanUtils.toBoolean("TrUE"));
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assertEquals(true, BooleanUtils.toBoolean("TrUe"));
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assertEquals(true, BooleanUtils.toBoolean("TruE"));
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assertEquals(true, BooleanUtils.toBoolean("True"));
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assertEquals(true, BooleanUtils.toBoolean("on"));
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assertEquals(true, BooleanUtils.toBoolean("oN"));
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assertEquals(true, BooleanUtils.toBoolean("On"));
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assertEquals(true, BooleanUtils.toBoolean("ON"));
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assertEquals(true, BooleanUtils.toBoolean("yes"));
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assertEquals(true, BooleanUtils.toBoolean("yeS"));
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assertEquals(true, BooleanUtils.toBoolean("yEs"));
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assertEquals(true, BooleanUtils.toBoolean("yES"));
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assertEquals(true, BooleanUtils.toBoolean("Yes"));
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assertEquals(true, BooleanUtils.toBoolean("YeS"));
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assertEquals(true, BooleanUtils.toBoolean("YEs"));
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assertEquals(true, BooleanUtils.toBoolean("YES"));
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}
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public void test_toBoolean_String_String_String() {
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