Android编程之MD5加密算法实例分析

package com.tencent.utils;import java.security.MessageDigest;import java.security.NoSuchAlgorithmException;/**  * 对外提供getMD5(String)方法  * @author randyjia  *  */ public class MD5 { public static String getMD5(String val) throws NoSuchAlgorithmException{  MessageDigest md5 = MessageDigest.getInstance("MD5");  md5.update(val.getBytes());  byte[] m = md5.digest();//加密  return getString(m);} private static String getString(byte[] b){  StringBuffer sb = new StringBuffer();   for(int i = 0; i < b.length; i ++){   sb.append(b[i]);   }   return sb.toString();}}

/* * MD5加密 */ private String getMD5Str(String str) {  MessageDigest messageDigest = null;  try {   messageDigest = MessageDigest.getInstance("MD5");   messageDigest.reset();   messageDigest.update(str.getBytes("UTF-8"));  } catch (NoSuchAlgorithmException e) {   System.out.println("NoSuchAlgorithmException caught!");   System.exit(-1);  } catch (UnsupportedEncodingException e) {   e.printStackTrace();  }  byte[] byteArray = messageDigest.digest();  StringBuffer md5StrBuff = new StringBuffer();  for (int i = 0; i < byteArray.length; i++) {   if (Integer.toHexString(0xFF & byteArray[i]).length() == 1)    md5StrBuff.append("0").append(Integer.toHexString(0xFF & byteArray[i]));   else    md5StrBuff.append(Integer.toHexString(0xFF & byteArray[i]));  } //16位加密，从第9位到25位  return md5StrBuff.substring(8, 24).toString().toUpperCase();}

public static String md5(String string) { byte[] hash; try {  hash = MessageDigest.getInstance("MD5").digest(string.getBytes("UTF-8")); } catch (NoSuchAlgorithmException e) {  throw new RuntimeException("Huh, MD5 should be supported?", e); } catch (UnsupportedEncodingException e) {  throw new RuntimeException("Huh, UTF-8 should be supported?", e); } StringBuilder hex = new StringBuilder(hash.length * 2); for (byte b : hash) {  if ((b & 0xFF) < 0x10) hex.append("0");  hex.append(Integer.toHexString(b & 0xFF)); } return hex.toString();}