Added ordinalIndexOf() and associated unit tests.

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/lang/trunk@137663 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/lang/StringUtils.java

@@ -145,7 +145,7 @@ import java.util.List;
  * @author Gary Gregory
  * @author Phil Steitz
  * @since 1.0
- * @version $Id: StringUtils.java,v 1.107 2003/08/23 10:39:20 scolebourne Exp $
+ * @version $Id: StringUtils.java,v 1.108 2003/09/04 18:18:18 ggregory Exp $
  */
 public class StringUtils {
     // Performance testing notes (JDK 1.4, Jul03, scolebourne)
@@ -170,6 +170,12 @@ public class StringUtils {
      */
     public static final String EMPTY = "";
 
+    /**
+     * Represents a failed index search.
+     * @since 2.?.?
+     */
+    public static final int INDEX_NOT_FOUND = -1;
+
     /**
      * <p>The maximum size to which the padding constant(s) can expand.</p>
      */
@@ -810,6 +816,52 @@ public class StringUtils {
         return str.indexOf(searchStr);
     }
 
+    /**
+     * <p>Finds the n-th index within a String, handling <code>null</code>.
+     * This method uses {@link String#indexOf(String)}.</p>
+     *
+     * <p>A <code>null</code> String will return <code>-1</code>.</p>
+     * 
+     * <pre>
+     * StringUtils.ordinalIndexOf(null, *, *)          = -1
+     * StringUtils.ordinalIndexOf(*, null, *)          = -1
+     * StringUtils.ordinalIndexOf("", "", *)           = 0
+     * StringUtils.ordinalIndexOf("aabaabaa", "a", 1)  = 0
+     * StringUtils.ordinalIndexOf("aabaabaa", "a", 2)  = 1
+     * StringUtils.ordinalIndexOf("aabaabaa", "b", 1)  = 2
+     * StringUtils.ordinalIndexOf("aabaabaa", "b", 2)  = 5
+     * StringUtils.ordinalIndexOf("aabaabaa", "ab", 1) = 1
+     * StringUtils.ordinalIndexOf("aabaabaa", "ab", 2) = 4
+     * StringUtils.ordinalIndexOf("aabaabaa", "", 1)   = 0
+     * StringUtils.ordinalIndexOf("aabaabaa", "", 2)   = 0
+     * </pre>
+     * 
+     * @param str  the String to check, may be null
+     * @param searchStr  the String to find, may be null
+     * @param ordinal  the n-th <code>searchStr</code> to find
+     * @return the n-th index of the search String,
+     *  <code>-1</code> (<code>INDEX_NOT_FOUND</code>) if no match or <code>null</code> string input
+     * @since 2.?.?
+     */
+    public static int ordinalIndexOf(String str, String searchStr, int ordinal) {
+        if (str == null || searchStr == null || ordinal <= 0) {
+            return INDEX_NOT_FOUND;
+        }
+        if (searchStr.length() == 0) {
+            return 0;
+        }
+        int found = 0;
+        int index = INDEX_NOT_FOUND;
+        do {
+            index = str.indexOf(searchStr, index + 1);
+            if (index < 0) {
+                return index;
+            }
+            found++;
+        } while (found < ordinal);
+        return index;
+    }
+
     /**
      * <p>Finds the first index within a String, handling <code>null</code>.
      * This method uses {@link String#indexOf(String, int)}.</p>
@@ -2256,9 +2308,11 @@ public class StringUtils {
         // ArraySize ==  0: Len = 0
         // ArraySize > 0:   Len = NofStrings *(len(firstString) + len(separator))
         //           (Assuming that all Strings are roughly equally long)
-        int bufSize 
+        int bufSize =
-            = ((arraySize == 0) ? 0 
+            ((arraySize == 0)
-                : arraySize * ((array[0] == null ? 16 : array[0].toString().length()) 
+                ? 0
+                : arraySize
+                    * ((array[0] == null ? 16 : array[0].toString().length())
                         + ((separator != null) ? separator.length() : 0)));
 
         StringBuffer buf = new StringBuffer(bufSize);
@@ -2956,7 +3010,6 @@ public class StringUtils {
         return str.substring(0, lastIdx);
     }
 
-
     // Conversion
     //-----------------------------------------------------------------------
     /**
@@ -3697,8 +3750,7 @@ public class StringUtils {
         }
         int sz = str.length();
         for (int i = 0; i < sz; i++) {
-            if ((Character.isLetter(str.charAt(i)) == false) &&
+            if ((Character.isLetter(str.charAt(i)) == false) && (str.charAt(i) != ' ')) {
-                (str.charAt(i) != ' ')) {
                 return false;
             }
         }
@@ -3765,8 +3817,7 @@ public class StringUtils {
         }
         int sz = str.length();
         for (int i = 0; i < sz; i++) {
-            if ((Character.isLetterOrDigit(str.charAt(i)) == false) &&
+            if ((Character.isLetterOrDigit(str.charAt(i)) == false) && (str.charAt(i) != ' ')) {
-                (str.charAt(i) != ' ')) {
                 return false;
             }
         }
@@ -3836,8 +3887,7 @@ public class StringUtils {
         }
         int sz = str.length();
         for (int i = 0; i < sz; i++) {
-            if ((Character.isDigit(str.charAt(i)) == false) &&
+            if ((Character.isDigit(str.charAt(i)) == false) && (str.charAt(i) != ' ')) {
-                (str.charAt(i) != ' ')) {
                 return false;
             }
         }
@@ -4192,7 +4242,6 @@ public class StringUtils {
         return -1;
     }
 
-
     // Misc
     //-----------------------------------------------------------------------
     /**
@@ -4301,4 +4350,3 @@ public class StringUtils {
     }
 
 }
-

src/test/org/apache/commons/lang/StringUtilsEqualsIndexOfTest.java

@@ -64,7 +64,7 @@ import junit.textui.TestRunner;
  * @author <a href="mailto:scolebourne@joda.org">Stephen Colebourne</a>
  * @author <a href="mailto:ridesmet@users.sourceforge.net">Ringo De Smet</a>
  * @author Phil Steitz
- * @version $Id: StringUtilsEqualsIndexOfTest.java,v 1.8 2003/08/18 02:22:25 bayard Exp $
+ * @version $Id: StringUtilsEqualsIndexOfTest.java,v 1.9 2003/09/04 18:18:18 ggregory Exp $
  */
 public class StringUtilsEqualsIndexOfTest extends TestCase {
     private static final String FOO = "foo";
@@ -146,6 +146,68 @@ public class StringUtilsEqualsIndexOfTest extends TestCase {
         assertEquals(0, StringUtils.indexOf("aabaabaa", ""));
     }
 
+    public void testOrdinalIndexOf() {
+        assertEquals(-1, StringUtils.ordinalIndexOf(null, null, Integer.MIN_VALUE));
+        assertEquals(-1, StringUtils.ordinalIndexOf("", null, Integer.MIN_VALUE));
+        assertEquals(-1, StringUtils.ordinalIndexOf("", "", Integer.MIN_VALUE));
+        assertEquals(-1, StringUtils.ordinalIndexOf("aabaabaa", "a", Integer.MIN_VALUE));
+        assertEquals(-1, StringUtils.ordinalIndexOf("aabaabaa", "b", Integer.MIN_VALUE));
+        assertEquals(-1, StringUtils.ordinalIndexOf("aabaabaa", "ab", Integer.MIN_VALUE));
+        assertEquals(-1, StringUtils.ordinalIndexOf("aabaabaa", "", Integer.MIN_VALUE));
+        
+        assertEquals(-1, StringUtils.ordinalIndexOf(null, null, -1));
+        assertEquals(-1, StringUtils.ordinalIndexOf("", null, -1));
+        assertEquals(-1, StringUtils.ordinalIndexOf("", "", -1));
+        assertEquals(-1, StringUtils.ordinalIndexOf("aabaabaa", "a", -1));
+        assertEquals(-1, StringUtils.ordinalIndexOf("aabaabaa", "b", -1));
+        assertEquals(-1, StringUtils.ordinalIndexOf("aabaabaa", "ab", -1));
+        assertEquals(-1, StringUtils.ordinalIndexOf("aabaabaa", "", -1));
+
+        assertEquals(-1, StringUtils.ordinalIndexOf(null, null, 0));
+        assertEquals(-1, StringUtils.ordinalIndexOf("", null, 0));
+        assertEquals(-1, StringUtils.ordinalIndexOf("", "", 0));
+        assertEquals(-1, StringUtils.ordinalIndexOf("aabaabaa", "a", 0));
+        assertEquals(-1, StringUtils.ordinalIndexOf("aabaabaa", "b", 0));
+        assertEquals(-1, StringUtils.ordinalIndexOf("aabaabaa", "ab", 0));
+        assertEquals(-1, StringUtils.ordinalIndexOf("aabaabaa", "", 0));
+
+        assertEquals(-1, StringUtils.ordinalIndexOf(null, null, 1));
+        assertEquals(-1, StringUtils.ordinalIndexOf("", null, 1));
+        assertEquals(0, StringUtils.ordinalIndexOf("", "", 1));
+        assertEquals(0, StringUtils.ordinalIndexOf("aabaabaa", "a", 1));
+        assertEquals(2, StringUtils.ordinalIndexOf("aabaabaa", "b", 1));
+        assertEquals(1, StringUtils.ordinalIndexOf("aabaabaa", "ab", 1));
+        assertEquals(0, StringUtils.ordinalIndexOf("aabaabaa", "", 1));
+
+        assertEquals(-1, StringUtils.ordinalIndexOf(null, null, 2));
+        assertEquals(-1, StringUtils.ordinalIndexOf("", null, 2));
+        assertEquals(0, StringUtils.ordinalIndexOf("", "", 2));
+        assertEquals(1, StringUtils.ordinalIndexOf("aabaabaa", "a", 2));
+        assertEquals(5, StringUtils.ordinalIndexOf("aabaabaa", "b", 2));
+        assertEquals(4, StringUtils.ordinalIndexOf("aabaabaa", "ab", 2));
+        assertEquals(0, StringUtils.ordinalIndexOf("aabaabaa", "", 2));
+        
+        assertEquals(-1, StringUtils.ordinalIndexOf(null, null, Integer.MAX_VALUE));
+        assertEquals(-1, StringUtils.ordinalIndexOf("", null, Integer.MAX_VALUE));
+        assertEquals(0, StringUtils.ordinalIndexOf("", "", Integer.MAX_VALUE));
+        assertEquals(-1, StringUtils.ordinalIndexOf("aabaabaa", "a", Integer.MAX_VALUE));
+        assertEquals(-1, StringUtils.ordinalIndexOf("aabaabaa", "b", Integer.MAX_VALUE));
+        assertEquals(-1, StringUtils.ordinalIndexOf("aabaabaa", "ab", Integer.MAX_VALUE));
+        assertEquals(0, StringUtils.ordinalIndexOf("aabaabaa", "", Integer.MAX_VALUE));
+        
+        assertEquals(-1, StringUtils.ordinalIndexOf("aaaaaaaaa", "a", 0));
+        assertEquals(0, StringUtils.ordinalIndexOf("aaaaaaaaa", "a", 1));
+        assertEquals(1, StringUtils.ordinalIndexOf("aaaaaaaaa", "a", 2));
+        assertEquals(2, StringUtils.ordinalIndexOf("aaaaaaaaa", "a", 3));
+        assertEquals(3, StringUtils.ordinalIndexOf("aaaaaaaaa", "a", 4));
+        assertEquals(4, StringUtils.ordinalIndexOf("aaaaaaaaa", "a", 5));
+        assertEquals(5, StringUtils.ordinalIndexOf("aaaaaaaaa", "a", 6));
+        assertEquals(6, StringUtils.ordinalIndexOf("aaaaaaaaa", "a", 7));
+        assertEquals(7, StringUtils.ordinalIndexOf("aaaaaaaaa", "a", 8));
+        assertEquals(8, StringUtils.ordinalIndexOf("aaaaaaaaa", "a", 9));
+        assertEquals(-1, StringUtils.ordinalIndexOf("aaaaaaaaa", "a", 10));
+    }
+
     public void testIndexOf_StringInt() {
         assertEquals(-1, StringUtils.indexOf(null, null, 0));
         assertEquals(-1, StringUtils.indexOf(null, null, -1));