Java tutorial
//package com.java2s; //License from project: Apache License import static java.util.Locale.US; import android.text.TextUtils; import java.io.UnsupportedEncodingException; import java.math.BigInteger; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; import java.util.Arrays; public class Main { /** * Length of generated hash */ public static final int HASH_LENGTH = 32; /** * Algorithm used for hashing */ public static final String HASH_ALGORITHM = "MD5"; /** * Charset used for hashing */ public static final String CHARSET = "CP1252"; /** * Get avatar hash for specified e-mail address * * @param email * @return hash */ public static String getHash(String email) { if (TextUtils.isEmpty(email)) return null; email = email.trim().toLowerCase(US); return email.length() > 0 ? digest(email) : null; } private static String digest(final String value) { byte[] digested; try { digested = MessageDigest.getInstance(HASH_ALGORITHM).digest(value.getBytes(CHARSET)); } catch (NoSuchAlgorithmException e) { return null; } catch (UnsupportedEncodingException e) { return null; } String hashed = new BigInteger(1, digested).toString(16); int padding = HASH_LENGTH - hashed.length(); if (padding == 0) return hashed; char[] zeros = new char[padding]; Arrays.fill(zeros, '0'); return new StringBuilder(HASH_LENGTH).append(zeros).append(hashed).toString(); } }