Added HexToAscii example.

core-java/src/main/java/com/baeldung/hextToAscii/HexToAscii.java

@@ -0,0 +1,38 @@
+package com.baeldung.hexToAscii;
+
+public class HexToAscii {
+
+    public static void main(String[] args) {
+
+        String demoString = "http://www.baeldung.com/jackson-serialize-dates";
+
+        System.out.println("Original statement: " + demoString);
+
+        String hexEquivalent = asciiToHex(demoString);
+        System.out.println("Hex equivalent: " + hexEquivalent);
+
+        String asciiEquivalent = hexToASCII(hexEquivalent);
+        System.out.println("Ascii equivalent: " + asciiEquivalent);
+    }
+
+    private static String asciiToHex(String asciiStr) {
+
+        char[] chars = asciiStr.toCharArray();
+        StringBuilder hex = new StringBuilder();
+        for (char ch : chars) {
+            hex.append(Integer.toHexString((int) ch));
+        }
+
+        return hex.toString();
+    }
+
+    private static String hexToASCII(String hexStr) {
+
+        StringBuilder output = new StringBuilder("");
+        for (int i = 0; i < hexStr.length(); i += 2) {
+            String str = hexStr.substring(i, i + 2);
+            output.append((char) Integer.parseInt(str, 16));
+        }
+        return output.toString();
+    }
+}