Java tutorial
//package com.java2s; import java.io.UnsupportedEncodingException; public class Main { public static String stringToHexString(String input, String encoding) throws UnsupportedEncodingException { return input != null ? toHex(input.getBytes(encoding)) : null; } public static String stringToHexString(String input) { try { return stringToHexString(input, "UTF-8"); } catch (UnsupportedEncodingException e) { throw new IllegalStateException("UTF-8 encoding is not supported by JVM"); } } public static String toHex(byte input[]) { if (input == null) return null; StringBuffer output = new StringBuffer(input.length * 2); for (int i = 0; i < input.length; i++) { int current = input[i] & 0xff; if (current < 16) output.append("0"); output.append(Integer.toString(current, 16)); } return output.toString(); } }