package com.john.j2se.util;??? ?
/**?? ?
?* MD5加密算法 ,是一種單向加密算法。 ?
?*/?? ?
import java.security.MessageDigest;??? ?
?? ?
public class MD5Util {??? ?
??? public final static String MD5(String s) {??? ?
??????? char hexDigits[] = { '0', '1', '2', '3', '4',??? ?
???????????????????????????? '5', '6', '7', '8', '9',??? ?
???????????????????????????? 'A', 'B', 'C', 'D', 'E', 'F'};??? ?
??????? try {??? ?
??????????? byte[] btInput = s.getBytes();??? ?
??????????? MessageDigest mdInst = MessageDigest.getInstance("MD5");??? ?
??????????? mdInst.update(btInput);??? ?
??????????? byte[] md = mdInst.digest();??? ?
??????????? int j = md.length;??? ?
??????????? char str[] = new char[j * 2];??? ?
??????????? int k = 0;??? ?
??????????? for (int i = 0; i < j; i++) {??? ?
??????????????? byte byte0 = md[i];??? ?
??????????????? str[k++] = hexDigits[byte0 >>> 4 & 0xf];??? ?
??????????????? str[k++] = hexDigits[byte0 & 0xf];??? ?
??????????? }??? ?
??????????? return new String(str);??? ?
??????? }??? ?
??????? catch (Exception e) {??? ?
??????????? e.printStackTrace();??? ?
??????????? return null;??? ?
??????? }??? ?
??? }??? ?
}?


/**
?* Base64 是一種雙向加密算法
?*/
import java.io.UnsupportedEncodingException;????
??
public class Base64 {????
??? private static char[] base64EncodeChars = new char[] {????
??????? 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',????
??????? 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',????
??????? 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',????
??????? 'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',????
??????? 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',????
??????? 'o', 'p', 'q', 'r', 's', 't', 'u', 'v',????
??????? 'w', 'x', 'y', 'z', '0', '1', '2', '3',????
??????? '4', '5', '6', '7', '8', '9', '+', '/' };????
???
??? private static byte[] base64DecodeChars = new byte[] {????
??? -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,????
??? -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,????
??? -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,????
??? 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,????
??? -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,????
??? 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,????
??? -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,????
??? 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1 };

? //編碼??? ?
??? public static String encode(byte[] data) {??? ?
??????? StringBuffer sb = new StringBuffer();??? ?
??????? int len = data.length;??? ?
??????? int i = 0;??? ?
??????? int b1, b2, b3;??? ?
??????? while (i < len) {??? ?
??????????? b1 = data[i++] & 0xff;??? ?
??????????? if (i == len)??? ?
??????????? {??? ?
??????????????? sb.append(base64EncodeChars[b1 >>> 2]);??? ?
??????????????? sb.append(base64EncodeChars[(b1 & 0x3) << 4]);??? ?
??????????????? sb.append("==");??? ?
??????????????? break;??? ?
??????????? }??? ?
??????????? b2 = data[i++] & 0xff;??? ?
??????????? if (i == len)??? ?
??????????? {??? ?
??????????????? sb.append(base64EncodeChars[b1 >>> 2]);??? ?
??????????????? sb.append(base64EncodeChars[((b1 & 0x03) << 4) | ((b2 & 0xf0) >>> 4)]);??? ?
??????????????? sb.append(base64EncodeChars[(b2 & 0x0f) << 2]);??? ?
??????????????? sb.append("=");??? ?
??????????????? break;??? ?
??????????? }??? ?
??????????? b3 = data[i++] & 0xff;??? ?
??????????? sb.append(base64EncodeChars[b1 >>> 2]);??? ?
??????????? sb.append(base64EncodeChars[((b1 & 0x03) << 4) | ((b2 & 0xf0) >>> 4)]);??? ?
??????????? sb.append(base64EncodeChars[((b2 & 0x0f) << 2) | ((b3 & 0xc0) >>> 6)]);??? ?
??????????? sb.append(base64EncodeChars[b3 & 0x3f]);??? ?
??????? }??? ?
??????? return sb.toString();??? ?
??? }??? ?
??? //解碼??? ?
??? public static byte[] decode(String str) throws UnsupportedEncodingException {??? ?
??????? StringBuffer sb = new StringBuffer();??? ?
??????? byte[] data = str.getBytes("US-ASCII");??? ?
??????? int len = data.length;??? ?
??????? int i = 0;??? ?
??????? int b1, b2, b3, b4;??? ?
??????? while (i < len) {??? ?
??????????? /* b1 */?? ?
??????????? do {??? ?
??????????????? b1 = base64DecodeChars[data[i++]];??? ?
??????????? } while (i < len && b1 == -1);??? ?
??????????? if (b1 == -1) break;??? ?
??????????? /* b2 */?? ?
??????????? do {??? ?
??????????????? b2 = base64DecodeChars[data[i++]];???????????????
? ? ? ? ?? } while (i < len && b2 == -1);??? ?
??????????? if (b2 == -1) break;????
??????????? sb.append((char)((b1 << 2) | ((b2 & 0x30) >>> 4)));????
??????????? /* b3 */???
??????????? do {????
??????????????? b3 = data[i++];????
??????????????? if (b3 == 61) return sb.toString().getBytes("iso8859-1");????
??????????????? b3 = base64DecodeChars[b3];????
??????????? } while (i < len && b3 == -1);????
??????????? if (b3 == -1) break;????
??????????? sb.append((char)(((b2 & 0x0f) << 4) | ((b3 & 0x3c) >>> 2)));????
??????????? /* b4 */???
??????????? do {????
??????????????? b4 = data[i++];????
??????????????? if (b4 == 61) return sb.toString().getBytes("iso8859-1");????
??????????????? b4 = base64DecodeChars[b4];????
??????????? } while (i < len && b4 == -1);????
??????????? if (b4 == -1) break;????
??????????? sb.append((char)(((b3 & 0x03) << 6) | b4));????
??????? }????
??????? return sb.toString().getBytes("iso8859-1");????
??? }????
}??