java实现生成MD5码

import java.security.MessageDigest;import java.security.NoSuchAlgorithmException;/** * @author anyone * @version 1.0.0.0/2011-8-8 */public class MD5 {private static final byte RESULT_32 = 32;private static final byte RESULT_16 = 16;public static String encode32(String text){return encodeText(text, RESULT_32);}public static String encode16(String text){return encodeText(text, RESULT_16);}public static String encode32(byte[] bytes){return encodeBytes(bytes, RESULT_32);}public static String encode16(byte[] bytes){return encodeBytes(bytes, RESULT_16);}private static String encode(byte[] bytes, byte result){String resultStr = encode(bytes);if(RESULT_32 == result){return resultStr;}return resultStr.substring(8, 24);}private static String encodeBytes(byte[] bytes, byte result) {byte[] originalBytes = null;                   try {originalBytes = getBytes(bytes);} catch (NoSuchAlgorithmException e) {e.printStackTrace();}return encode(originalBytes, result);}private static String encodeText(String plainText, byte result) {byte[] originalBytes = null;                   try {originalBytes = getBytes(plainText);} catch (NoSuchAlgorithmException e) {e.printStackTrace();}return encode(originalBytes, result);}private static String encode(byte bytes[]){int i;StringBuffer buf = new StringBuffer();for (int offset = 0; offset < bytes.length; offset++) {i = bytes[offset];if (i < 0)i += 256;if (i < 16)buf.append("0");buf.append(Integer.toHexString(i));}return buf.toString();}private static byte[] getBytes(String plainText) throws NoSuchAlgorithmException{MessageDigest md5 = MessageDigest.getInstance("MD5");md5.update(plainText.getBytes());return md5.digest();}private static byte[] getBytes(byte[] bytes) throws NoSuchAlgorithmException{MessageDigest md5 = MessageDigest.getInstance("MD5");md5.update(bytes);return md5.digest();}//public static void main(String[] args){//System.out.println(MD5.encode32("abc")); // 900150983cd24fb0d6963f7d28e17f72//System.out.println(MD5.encode32("abc".getBytes())); // 900150983cd24fb0d6963f7d28e17f72//System.out.println(MD5.encode32("")); // d41d8cd98f00b204e9800998ecf8427e//System.out.println(MD5.encode32("".getBytes())); // d41d8cd98f00b204e9800998ecf8427e//System.out.println(MD5.encode32("abcdefghijklmnopqrstuvwxyz")); // c3fcd3d76192e4007dfb496cca67e13b//System.out.println(MD5.encode32("abcdefghijklmnopqrstuvwxyz".getBytes())); // c3fcd3d76192e4007dfb496cca67e13b//System.out.println(MD5.encode32("message digest"));// f96b697d7cb7938d525a2f31aaf161d0//System.out.println(MD5.encode32("message digest".getBytes()));// f96b697d7cb7938d525a2f31aaf161d0//}}