Add Java snippet to print spiral of 2d array

.gitignore

@@ -96,6 +96,7 @@
 #!language/java/project/sa-calculator/
 !language/java/snippet/
 !language/java/snippet/DoubleBraceInitialization.java
+!language/java/snippet/PrintSpiral.java
 !language/java/snippet/TwoPlusTwoEqualsFive.java
 !language/javascript/
 !language/haskell/

language/java/snippet/PrintSpiral.java

@@ -0,0 +1,33 @@
+public class PrintSpiral {
+
+  public static void main(String[] args) {
+    int[][] arr = {{1, 2, 3, 4, 5},
+                    {6, 7, 8, 9, 10},
+                    {11, 12, 13, 14, 15},
+                    {16, 17, 18, 19, 20},
+                    {21, 22, 23, 24, 25}};
+    String spiralOrder = printSpriral(arr);
+    System.out.println("spiralOrder=" + spiralOrder);
+  }
+
+  public static String printSpriral(int[][] arr) {
+    int rowMin = 0;
+    int colMin = 0;
+    int rowMax = arr.length - 1;
+    int colMax = arr[0].length - 1;
+    int direction = 0; // right, down, left, up
+    StringBuilder sb = new StringBuilder();
+    for (int row = rowMin, col = colMin; rowMin <= rowMax && colMin <= colMax; ) {
+      sb.append(arr[row][col]).append(" ");
+      // Navigate direction.
+      switch (direction) {
+        case 0: if (col < colMax) { col++; } else { direction = 1; row++; rowMin++; } break;
+        case 1: if (row < rowMax) { row++; } else { direction = 2; col--; colMax--; } break;
+        case 2: if (col > colMin) { col--; } else { direction = 3; row--; rowMax--; } break;
+        case 3: if (row > rowMin) { row--; } else { direction = 0; col++; colMin++; } break;
+      }
+    }
+    return sb.toString();
+  }
+
+}