[LANG-1119] Add rotate(string, int) method to StringUtils

• Type: New Feature
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.5
• Component/s: lang.*
• Assignee: Benedikt Ritter
• Reporter: Loic Guibert
• Created: 26/Apr/15 12:55
• Updated: 19/Oct/16 07:01
• Resolved: 28/Apr/15 19:58

Description

Add a method to rotate (circular shift) a String into StringUtils.

/**
 * <p>Rotate (circular shift) a String of {@code shift} characters.</p>
 * <ul>
 *  <li>If {@code shift > 0}, right circular shift (ex : ABCDEF =&gt; FABCDE)</li>
 *  <li>If {@code shift < 0}, left circular shift (ex : ABCDEF =&gt; BCDEFA)</li>
 * </ul>
 *
 * <pre>
 * StringUtils.rotate(null, *)        = null
 * StringUtils.rotate("", *)          = ""
 * StringUtils.rotate("abcdefg", 0)   = "abcdefg"
 * StringUtils.rotate("abcdefg", 2)   = "fgabcde"
 * StringUtils.rotate("abcdefg", -2)  = "cdefgab"
 * StringUtils.rotate("abcdefg", 7)   = "abcdefg"
 * StringUtils.rotate("abcdefg", -7)  = "abcdefg"
 * StringUtils.rotate("abcdefg", 9)   = "fgabcde"
 * StringUtils.rotate("abcdefg", -9)  = "cdefgab"
 * </pre>
 *
 * @param str  the String to rotate, may be null
 * @param shift  number of time to shift (positive : right shift, negative : left shift)
 * @return the rotated String,
 *          or the original String if {@code shift == 0},
 *          or {@code null} if null String input
 */
public static String rotate(String str, int shift);

See PR #71 : https://github.com/apache/commons-lang/pull/71