Fixed #29. Added support for shuffle function

src/main/java/strman/Strman.java

@@ -96,17 +96,8 @@ public abstract class Strman {
      * @return character array
      */
     public static String[] chars(final String value) {
-        /**
-         * The other implementation of this could be using String's split method
-         * String[] chars = value.split("")
-         */
         validate(value, NULL_STRING_PREDICATE, NULL_STRING_MSG_SUPPLIER);
-        int length = value.length();
-        String[] result = new String[length];
-        for (int i = 0; i < length; i++) {
-            result[i] = at(value, i).get();
-        }
-        return result;
+        return value.split("");
     }
 
 
@@ -908,6 +899,25 @@ public abstract class Strman {
         return html.chars().mapToObj(c -> "\\u" + String.format("%04x", c).toUpperCase()).map(e -> HtmlEntities.encodedEntities.get(e)).collect(joining());
     }
 
+    /**
+     * It returns a string with its characters in random order.
+     *
+     * @param value The input String
+     * @return The shuffled String
+     */
+    public static String shuffle(final String value) {
+        validate(value, NULL_STRING_PREDICATE, NULL_STRING_MSG_SUPPLIER);
+        String[] chars = chars(value);
+        Random random = new Random();
+        for (int i = 0; i < chars.length; i++) {
+            int r = random.nextInt(chars.length);
+            String tmp = chars[i];
+            chars[i] = chars[r];
+            chars[r] = tmp;
+        }
+        return Arrays.stream(chars).collect(joining());
+    }
+
     public static String decode(final String value, final int digits, final int radix) {
         validate(value, NULL_STRING_PREDICATE, NULL_STRING_MSG_SUPPLIER);
         return Arrays

src/test/java/strman/StrmanTest.java

@@ -6,12 +6,12 @@ import java.util.Arrays;
 import java.util.Optional;
 
 import static java.util.stream.Collectors.toList;
-import static org.hamcrest.CoreMatchers.equalTo;
-import static org.hamcrest.CoreMatchers.hasItems;
+import static org.hamcrest.CoreMatchers.*;
 import static org.hamcrest.collection.IsArrayContainingInOrder.arrayContaining;
 import static org.hamcrest.collection.IsArrayWithSize.emptyArray;
 import static org.junit.Assert.*;
 import static strman.Strman.*;
+import static strman.Strman.endsWith;
 import static strman.Strman.format;
 
 public class StrmanTest {
@@ -663,4 +663,13 @@ public class StrmanTest {
         assertThat(htmlEncode("Ж"), equalTo("Ж"));
         assertThat(htmlEncode("┐"), equalTo("┐"));
     }
+
+    @Test
+    public void shuffle_shouldShuffleAString() throws Exception {
+        assertThat(shuffle("shekhar"), not(equalTo("shekhar")));
+        assertThat(shuffle("strman"), not(equalTo("strman")));
+        assertThat(shuffle(""), equalTo(""));
+        assertThat(shuffle("s"), equalTo("s"));
+
+    }
 }