对登录实现加密，通用工具类（支持MD5和SHA）

action sql查询：

 List<User> uList = CommonDao.findBySQL("from User where username='"+username+"' and password='"+PWDUtil.getSHA(password)+"'");

 

工具类代码：

 

package com.alpha.util; /** * MD5 ＆ SHA 加密 * @author JavaAlpha * @date 2011-6-21 * @version V 1.0 */ import java.io.UnsupportedEncodingException; import java.security.MessageDigest; import java.security.NoSuchAlgorithmException; public class PWDUtil { public static void main(String[] args) { //md5加密测试 String md5_1 = getMD5("123"); System.out.println(md5_1); System.out.println("md5 length: " + md5_1.length()); //sha加密测试 String sha_1 = getSHA("123"); System.out.println(sha_1); System.out.println("sha length: " + sha_1.length()); } // md5加密 public static String getMD5(String inputText) { return encrypt(inputText, "md5"); } // sha加密 public static String getSHA(String inputText) { return encrypt(inputText, "sha-1"); } /** * md5或者sha-1加密 * * @param inputText * 要加密的内容 * @param algorithmName * 加密算法名称：md5或者sha-1，不区分大小写 * @return */ private static String encrypt(String inputText, String algorithmName) { if (inputText == null || "".equals(inputText.trim())) { throw new IllegalArgumentException("请输入要加密的内容"); } if (algorithmName == null || "".equals(algorithmName.trim())) { algorithmName = "md5"; } String encryptText = null; try { MessageDigest m = MessageDigest.getInstance(algorithmName); m.update(inputText.getBytes("UTF8")); byte s[] = m.digest(); // m.digest(inputText.getBytes("UTF8")); return hex(s); } catch (NoSuchAlgorithmException e) { e.printStackTrace(); } catch (UnsupportedEncodingException e) { e.printStackTrace(); } return encryptText; } // 返回十六进制字符串 private static String hex(byte[] arr) { StringBuffer sb = new StringBuffer(); for (int i = 0; i < arr.length; ++i) { sb.append(Integer.toHexString((arr[i] & 0xFF) | 0x100).substring(1, 3)); } return sb.toString(); } }