svn commit: r826955 - in /commons/proper/lang/trunk/src: java/org/apache/commons/lang/StringUtils.java test/org/apache/commons/lang/StringUtilsTest.java

[ba...@apache.org]

Author: bayard
Date: Tue Oct 20 05:18:57 2009
New Revision: 826955

URL: http://svn.apache.org/viewvc?rev=826955&view=rev
Log:
Adding a StringUtils.repeat(String, String separator, int) method per request in LANG-348

Modified:
    commons/proper/lang/trunk/src/java/org/apache/commons/lang/StringUtils.java
    commons/proper/lang/trunk/src/test/org/apache/commons/lang/StringUtilsTest.java

Modified: commons/proper/lang/trunk/src/java/org/apache/commons/lang/StringUtils.java
URL: http://svn.apache.org/viewvc/commons/proper/lang/trunk/src/java/org/apache/commons/lang/StringUtils.java?rev=826955&r1=826954&r2=826955&view=diff
==============================================================================
--- commons/proper/lang/trunk/src/java/org/apache/commons/lang/StringUtils.java (original)
+++ commons/proper/lang/trunk/src/java/org/apache/commons/lang/StringUtils.java Tue Oct 20 05:18:57 2009
@@ -4018,6 +4018,35 @@
     }
 
     /**
+     * <p>Repeat a String <code>repeat</code> times to form a
+     * new String, with a String separator injected each time. </p>
+     *
+     * <pre>
+     * StringUtils.repeat(null, null, 2) = null
+     * StringUtils.repeat(null, "x", 2)  = null
+     * StringUtils.repeat("", null, 0)   = ""
+     * StringUtils.repeat("", "", 2)     = ""
+     * StringUtils.repeat("", "x", 3)    = "xxx"
+     * StringUtils.repeat("?", ", ", 3)  = "?, ?, ?"
+     * </pre>
+     *
+     * @param str        the String to repeat, may be null
+     * @param separator  the String to inject, may be null
+     * @param repeat     number of times to repeat str, negative treated as zero
+     * @return a new String consisting of the original String repeated,
+     *  <code>null</code> if null String input
+     */
+    public static String repeat(String str, String separator, int repeat) {
+        if(str == null || separator == null) {
+            return repeat(str, repeat);
+        } else {
+            // given that repeat(String, int) is quite optimized, better to rely on it than try and splice this into it
+            String result = repeat(str + separator, repeat);
+            return removeEnd(result, separator);
+        }
+    }
+
+    /**
      * <p>Returns padding using the specified delimiter repeated
      * to a given length.</p>
      *

Modified: commons/proper/lang/trunk/src/test/org/apache/commons/lang/StringUtilsTest.java
URL: http://svn.apache.org/viewvc/commons/proper/lang/trunk/src/test/org/apache/commons/lang/StringUtilsTest.java?rev=826955&r1=826954&r2=826955&view=diff
==============================================================================
--- commons/proper/lang/trunk/src/test/org/apache/commons/lang/StringUtilsTest.java (original)
+++ commons/proper/lang/trunk/src/test/org/apache/commons/lang/StringUtilsTest.java Tue Oct 20 05:18:57 2009
@@ -1153,6 +1153,19 @@
         assertEquals(true, StringUtils.containsOnly(str, new char[] {'a'}));
     }
 
+    public void testRepeat_StringStringInt() {
+        assertEquals(null, StringUtils.repeat(null, null, 2));
+        assertEquals(null, StringUtils.repeat(null, "x", 2));
+        assertEquals("", StringUtils.repeat("", null, 2));
+
+        assertEquals("", StringUtils.repeat("ab", "", 0));
+        assertEquals("", StringUtils.repeat("", "", 2));
+
+        assertEquals("xx", StringUtils.repeat("", "x", 3));
+
+        assertEquals("?, ?, ?", StringUtils.repeat("?", ", ", 3));
+    }
+
     public void testChop() {
 
         String[][] chopCases = {