Fix defaultIsEmpty typing.

git-svn-id: https://svn.apache.org/repos/asf/commons/proper/lang/trunk@922904 13f79535-47bb-0310-9956-ffa450edef68

src/main/java/org/apache/commons/lang3/CharSequenceUtils.java

@@ -38,9 +38,13 @@ public class CharSequenceUtils {
 	}
 
 	/**
-     * <p>Reverses a CharSequence as per {@link StringBuilder#reverse()}.</p>
+	 * <p>
+	 * Reverses a CharSequence as per {@link StringBuilder#reverse()}.
+	 * </p>
 	 * 
-     * <p>A <code>null</code> CharSequence returns <code>null</code>.</p>
+	 * <p>
+	 * A <code>null</code> CharSequence returns <code>null</code>.
+	 * </p>
 	 * 
 	 * <pre>
 	 * CharSequenceUtils.reverse(null) = null
@@ -48,7 +52,8 @@ public class CharSequenceUtils {
 	 * CharSequenceUtils.reverse("bat").toString() = "tab"
 	 * </pre>
 	 * 
-     * @param str  the String to reverse, may be null
+	 * @param str
+	 *            the String to reverse, may be null
 	 * @return the reversed String, <code>null</code> if null String input
 	 */
 	public static CharSequence reverse(CharSequence str) {
@@ -78,4 +83,39 @@ public class CharSequenceUtils {
 	public static CharSequence subSequence(CharSequence cs, int start) {
 		return cs == null ? null : cs.subSequence(start, cs.length());
 	}
+
+	public static int indexOf(CharSequence cs, int ch, int startPos) {
+		int max = cs.length();
+
+		if (startPos < 0) {
+			startPos = 0;
+		} else if (startPos >= max) {
+			return StringUtils.INDEX_NOT_FOUND;
+		}
+
+		if (ch < Character.MIN_SUPPLEMENTARY_CODE_POINT) {
+			for (int i = startPos; i < max; i++) {
+				if (cs.charAt(i) == ch) {
+					return i;
+				}
+			}
+			return StringUtils.INDEX_NOT_FOUND;
+		}
+
+		// supp chars
+		if (ch <= Character.MAX_CODE_POINT) {
+			char[] surrogates = Character.toChars(ch);
+			for (int i = startPos; i < max; i++) {
+				if (cs.charAt(i) == surrogates[0]) {
+					if (i + 1 == max) {
+						break;
+					}
+					if (cs.charAt(i + 1) == surrogates[1]) {
+						return i;
+					}
+				}
+			}
+		}
+		return StringUtils.INDEX_NOT_FOUND;
+	}
 }

src/main/java/org/apache/commons/lang3/StringUtils.java

@@ -5390,7 +5390,7 @@ public class StringUtils {
      *  if the input is empty ("") or <code>null</code>, may be null
      * @return the passed in CharSequence, or the default
      */
-    public static CharSequence defaultIfEmpty(CharSequence str, CharSequence defaultStr) {
+    public static <T extends CharSequence> T defaultIfEmpty(T str, T defaultStr) {
         return StringUtils.isEmpty(str) ? defaultStr : str;
     }
 

src/test/java/org/apache/commons/lang3/StringUtilsTest.java

@@ -1416,24 +1416,36 @@ public class StringUtilsTest extends TestCase {
         assertEquals("NULL", StringUtils.defaultIfEmpty("", "NULL"));
         assertEquals("abc", StringUtils.defaultIfEmpty("abc", "NULL"));
         assertNull(StringUtils.defaultIfEmpty("", null));
+        // Tests compatibility for the API return type
+        String s = StringUtils.defaultIfEmpty("abc", "NULL");
+        assertEquals("abc", s);
     }
 
     public void testDefaultIfEmpty_StringBuilders() {
         assertEquals("NULL", StringUtils.defaultIfEmpty(new StringBuilder(""), new StringBuilder("NULL")).toString());
         assertEquals("abc", StringUtils.defaultIfEmpty(new StringBuilder("abc"), new StringBuilder("NULL")).toString());
         assertNull(StringUtils.defaultIfEmpty(new StringBuilder(""), null));
+        // Tests compatibility for the API return type
+        StringBuilder s = StringUtils.defaultIfEmpty(new StringBuilder("abc"), new StringBuilder("NULL"));
+        assertEquals("abc", s.toString());
     }
 
     public void testDefaultIfEmpty_StringBuffers() {
         assertEquals("NULL", StringUtils.defaultIfEmpty(new StringBuffer(""), new StringBuffer("NULL")).toString());
         assertEquals("abc", StringUtils.defaultIfEmpty(new StringBuffer("abc"), new StringBuffer("NULL")).toString());
         assertNull(StringUtils.defaultIfEmpty(new StringBuffer(""), null));
+        // Tests compatibility for the API return type
+        StringBuffer s = StringUtils.defaultIfEmpty(new StringBuffer("abc"), new StringBuffer("NULL"));
+        assertEquals("abc", s.toString());
     }
 
     public void testDefaultIfEmpty_CharBuffers() {
         assertEquals("NULL", StringUtils.defaultIfEmpty(CharBuffer.wrap(""), CharBuffer.wrap("NULL")).toString());
         assertEquals("abc", StringUtils.defaultIfEmpty(CharBuffer.wrap("abc"), CharBuffer.wrap("NULL")).toString());
         assertNull(StringUtils.defaultIfEmpty(CharBuffer.wrap(""), null));
+        // Tests compatibility for the API return type
+        CharBuffer s = StringUtils.defaultIfEmpty(CharBuffer.wrap("abc"), CharBuffer.wrap("NULL"));
+        assertEquals("abc", s.toString());
     }
 
     //-----------------------------------------------------------------------