Java tutorial
//package com.java2s; /* * Copyright (C) 2016 android@19code.com * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.io.IOException; import java.io.InputStream; import java.security.DigestInputStream; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; public class Main { public static String encode(String input) { try { MessageDigest messageDigest = MessageDigest.getInstance("MD5"); byte[] inputByteArray = input.getBytes(); messageDigest.update(inputByteArray); byte[] resultByteArray = messageDigest.digest(); char[] hexDigits = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' }; char[] resultCharArray = new char[resultByteArray.length * 2]; int index = 0; for (byte b : resultByteArray) { resultCharArray[index++] = hexDigits[b >>> 4 & 0xf]; resultCharArray[index++] = hexDigits[b & 0xf]; } return new String(resultCharArray); } catch (NoSuchAlgorithmException e) { return null; } } public static String encode(InputStream in) { int bufferSize = 256 * 1024; DigestInputStream digestInputStream = null; try { MessageDigest messageDigest = MessageDigest.getInstance("MD5"); digestInputStream = new DigestInputStream(in, messageDigest); byte[] buffer = new byte[bufferSize]; while (digestInputStream.read(buffer) > 0) ; messageDigest = digestInputStream.getMessageDigest(); byte[] resultByteArray = messageDigest.digest(); char[] hexDigits = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' }; char[] resultCharArray = new char[resultByteArray.length * 2]; int index = 0; for (byte b : resultByteArray) { resultCharArray[index++] = hexDigits[b >>> 4 & 0xf]; resultCharArray[index++] = hexDigits[b & 0xf]; } return new String(resultCharArray); } catch (NoSuchAlgorithmException e) { return null; } catch (IOException e) { e.printStackTrace(); } finally { try { if (digestInputStream != null) digestInputStream.close(); } catch (Exception e) { e.printStackTrace(); } } return null; } }