Consistent hasText checks for CharSequence vs String

Issue: SPR-15540

spring-core/src/main/java/org/springframework/util/StringUtils.java

@@ -139,17 +139,7 @@ public abstract class StringUtils {
 	 * @see Character#isWhitespace
 	 */
 	public static boolean hasText(@Nullable 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;
+		return (hasLength(str) && containsText(str));
 	}
 
 	/**
@@ -163,9 +153,19 @@ public abstract class StringUtils {
 	 * @see #hasText(CharSequence)
 	 */
 	public static boolean hasText(@Nullable String str) {
-		return (str != null && !str.isEmpty() && hasText((CharSequence) str));
+		return (hasLength(str) && containsText(str));
 	}
 
+	private static boolean containsText(CharSequence str) {
+		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 {@code CharSequence} contains any whitespace characters.
 	 * @param str the {@code CharSequence} to check (may be {@code null})

spring-core/src/test/java/org/springframework/util/StringUtilsTests.java

@@ -32,24 +32,24 @@ import static org.junit.Assert.*;
 public class StringUtilsTests {
 
 	@Test
-	public void testHasTextBlank() throws Exception {
+	public void testHasTextBlank() {
 		String blank = "          ";
 		assertEquals(false, StringUtils.hasText(blank));
 	}
 
 	@Test
-	public void testHasTextNullEmpty() throws Exception {
+	public void testHasTextNullEmpty() {
 		assertEquals(false, StringUtils.hasText(null));
 		assertEquals(false, StringUtils.hasText(""));
 	}
 
 	@Test
-	public void testHasTextValid() throws Exception {
+	public void testHasTextValid() {
 		assertEquals(true, StringUtils.hasText("t"));
 	}
 
 	@Test
-	public void testContainsWhitespace() throws Exception {
+	public void testContainsWhitespace() {
 		assertFalse(StringUtils.containsWhitespace(null));
 		assertFalse(StringUtils.containsWhitespace(""));
 		assertFalse(StringUtils.containsWhitespace("a"));
@@ -62,7 +62,7 @@ public class StringUtilsTests {
 	}
 
 	@Test
-	public void testTrimWhitespace() throws Exception {
+	public void testTrimWhitespace() {
 		assertEquals(null, StringUtils.trimWhitespace(null));
 		assertEquals("", StringUtils.trimWhitespace(""));
 		assertEquals("", StringUtils.trimWhitespace(" "));
@@ -75,7 +75,7 @@ public class StringUtilsTests {
 	}
 
 	@Test
-	public void testTrimAllWhitespace() throws Exception {
+	public void testTrimAllWhitespace() {
 		assertEquals("", StringUtils.trimAllWhitespace(""));
 		assertEquals("", StringUtils.trimAllWhitespace(" "));
 		assertEquals("", StringUtils.trimAllWhitespace("\t"));
@@ -87,7 +87,7 @@ public class StringUtilsTests {
 	}
 
 	@Test
-	public void testTrimLeadingWhitespace() throws Exception {
+	public void testTrimLeadingWhitespace() {
 		assertEquals(null, StringUtils.trimLeadingWhitespace(null));
 		assertEquals("", StringUtils.trimLeadingWhitespace(""));
 		assertEquals("", StringUtils.trimLeadingWhitespace(" "));
@@ -100,7 +100,7 @@ public class StringUtilsTests {
 	}
 
 	@Test
-	public void testTrimTrailingWhitespace() throws Exception {
+	public void testTrimTrailingWhitespace() {
 		assertEquals(null, StringUtils.trimTrailingWhitespace(null));
 		assertEquals("", StringUtils.trimTrailingWhitespace(""));
 		assertEquals("", StringUtils.trimTrailingWhitespace(" "));
@@ -113,7 +113,7 @@ public class StringUtilsTests {
 	}
 
 	@Test
-	public void testTrimLeadingCharacter() throws Exception {
+	public void testTrimLeadingCharacter() {
 		assertEquals(null, StringUtils.trimLeadingCharacter(null, ' '));
 		assertEquals("", StringUtils.trimLeadingCharacter("", ' '));
 		assertEquals("", StringUtils.trimLeadingCharacter(" ", ' '));
@@ -126,7 +126,7 @@ public class StringUtilsTests {
 	}
 
 	@Test
-	public void testTrimTrailingCharacter() throws Exception {
+	public void testTrimTrailingCharacter() {
 		assertEquals(null, StringUtils.trimTrailingCharacter(null, ' '));
 		assertEquals("", StringUtils.trimTrailingCharacter("", ' '));
 		assertEquals("", StringUtils.trimTrailingCharacter(" ", ' '));
@@ -166,7 +166,7 @@ public class StringUtilsTests {
 	}
 
 	@Test
-	public void testReplace() throws Exception {
+	public void testReplace() {
 		String inString = "a6AazAaa77abaa";
 		String oldPattern = "aa";
 		String newPattern = "foo";
@@ -189,7 +189,7 @@ public class StringUtilsTests {
 	}
 
 	@Test
-	public void testDelete() throws Exception {
+	public void testDelete() {
 		String inString = "The quick brown fox jumped over the lazy dog";
 
 		String noThe = StringUtils.delete(inString, "the");
@@ -216,7 +216,7 @@ public class StringUtilsTests {
 	}
 
 	@Test
-	public void testDeleteAny() throws Exception {
+	public void testDeleteAny() {
 		String inString = "Able was I ere I saw Elba";
 
 		String res = StringUtils.deleteAny(inString, "I");
@@ -598,7 +598,7 @@ public class StringUtilsTests {
 
 
 	@Test
-	public void testParseLocaleStringSunnyDay() throws Exception {
+	public void testParseLocaleStringSunnyDay() {
 		Locale expectedLocale = Locale.UK;
 		Locale locale = StringUtils.parseLocaleString(expectedLocale.toString());
 		assertNotNull("When given a bona-fide Locale string, must not return null.", locale);
@@ -606,19 +606,19 @@ public class StringUtilsTests {
 	}
 
 	@Test
-	public void testParseLocaleStringWithMalformedLocaleString() throws Exception {
+	public void testParseLocaleStringWithMalformedLocaleString() {
 		Locale locale = StringUtils.parseLocaleString("_banjo_on_my_knee");
 		assertNotNull("When given a malformed Locale string, must not return null.", locale);
 	}
 
 	@Test
-	public void testParseLocaleStringWithEmptyLocaleStringYieldsNullLocale() throws Exception {
+	public void testParseLocaleStringWithEmptyLocaleStringYieldsNullLocale() {
 		Locale locale = StringUtils.parseLocaleString("");
 		assertNull("When given an empty Locale string, must return null.", locale);
 	}
 
 	@Test  // SPR-8637
-	public void testParseLocaleWithMultiSpecialCharactersInVariant() throws Exception {
+	public void testParseLocaleWithMultiSpecialCharactersInVariant() {
 		String variant = "proper-northern";
 		String localeString = "en_GB_" + variant;
 		Locale locale = StringUtils.parseLocaleString(localeString);
@@ -626,7 +626,7 @@ public class StringUtilsTests {
 	}
 
 	@Test  // SPR-3671
-	public void testParseLocaleWithMultiValuedVariant() throws Exception {
+	public void testParseLocaleWithMultiValuedVariant() {
 		String variant = "proper_northern";
 		String localeString = "en_GB_" + variant;
 		Locale locale = StringUtils.parseLocaleString(localeString);
@@ -634,7 +634,7 @@ public class StringUtilsTests {
 	}
 
 	@Test  // SPR-3671
-	public void testParseLocaleWithMultiValuedVariantUsingSpacesAsSeparators() throws Exception {
+	public void testParseLocaleWithMultiValuedVariantUsingSpacesAsSeparators() {
 		String variant = "proper northern";
 		String localeString = "en GB " + variant;
 		Locale locale = StringUtils.parseLocaleString(localeString);
@@ -642,7 +642,7 @@ public class StringUtilsTests {
 	}
 
 	@Test  // SPR-3671
-	public void testParseLocaleWithMultiValuedVariantUsingMixtureOfUnderscoresAndSpacesAsSeparators() throws Exception {
+	public void testParseLocaleWithMultiValuedVariantUsingMixtureOfUnderscoresAndSpacesAsSeparators() {
 		String variant = "proper northern";
 		String localeString = "en_GB_" + variant;
 		Locale locale = StringUtils.parseLocaleString(localeString);
@@ -650,7 +650,7 @@ public class StringUtilsTests {
 	}
 
 	@Test  // SPR-3671
-	public void testParseLocaleWithMultiValuedVariantUsingSpacesAsSeparatorsWithLotsOfLeadingWhitespace() throws Exception {
+	public void testParseLocaleWithMultiValuedVariantUsingSpacesAsSeparatorsWithLotsOfLeadingWhitespace() {
 		String variant = "proper northern";
 		String localeString = "en GB            " + variant;  // lots of whitespace
 		Locale locale = StringUtils.parseLocaleString(localeString);
@@ -658,7 +658,7 @@ public class StringUtilsTests {
 	}
 
 	@Test  // SPR-3671
-	public void testParseLocaleWithMultiValuedVariantUsingUnderscoresAsSeparatorsWithLotsOfLeadingWhitespace() throws Exception {
+	public void testParseLocaleWithMultiValuedVariantUsingUnderscoresAsSeparatorsWithLotsOfLeadingWhitespace() {
 		String variant = "proper_northern";
 		String localeString = "en_GB_____" + variant;  // lots of underscores
 		Locale locale = StringUtils.parseLocaleString(localeString);