Here you can find the source of sha1ToHex(String input, String encoding)
public static String sha1ToHex(String input, String encoding) throws Exception
//package com.java2s; import java.security.MessageDigest; public class Main { /**/*from w w w .j a v a 2s . c o m*/ * Used to build output as Hex */ private static final char[] DIGITS_LOWER = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' }; public static String sha1ToHex(String input, String encoding) throws Exception { byte[] digestResult = digest(input, "sha-1", encoding); return encodeHexString(digestResult); } private static byte[] digest(String input, String algorithm, String encoding) throws Exception { MessageDigest messageDigest = MessageDigest.getInstance(algorithm); return messageDigest.digest(input.getBytes(encoding)); } /** * Converts an array of bytes into a String representing the hexadecimal values of each byte in order. The returned * String will be double the length of the passed array, as it takes two characters to represent any given byte. * * @param data * a byte[] to convert to Hex characters * @return A String containing hexadecimal characters * @since 1.4 */ public static String encodeHexString(byte[] data) { return new String(encodeHex(data)); } /** * Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order. * The returned array will be double the length of the passed array, as it takes two characters to represent any * given byte. * * @param data * a byte[] to convert to Hex characters * @return A char[] containing hexadecimal characters */ public static char[] encodeHex(byte[] data) { return encodeHex(data, true); } /** * Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order. * The returned array will be double the length of the passed array, as it takes two characters to represent any * given byte. * * @param data * a byte[] to convert to Hex characters * @param toLowerCase * <code>true</code> converts to lowercase, <code>false</code> to uppercase * @return A char[] containing hexadecimal characters * @since 1.4 */ public static char[] encodeHex(byte[] data, boolean toLowerCase) { return encodeHex(data, DIGITS_LOWER); } /** * Converts an array of bytes into an array of characters representing the hexadecimal values of each byte in order. * The returned array will be double the length of the passed array, as it takes two characters to represent any * given byte. * * @param data * a byte[] to convert to Hex characters * @param toDigits * the output alphabet * @return A char[] containing hexadecimal characters * @since 1.4 */ protected static char[] encodeHex(byte[] data, char[] toDigits) { int l = data.length; char[] out = new char[l << 1]; // two characters form the hex value. for (int i = 0, j = 0; i < l; i++) { out[j++] = toDigits[(0xF0 & data[i]) >>> 4]; out[j++] = toDigits[0x0F & data[i]]; } return out; } }